Merge pull request #1 from dualfroz/feat/pending-work-2026-09

feat: land pending September work

src/abilities.lua

@@ -0,0 +1,263 @@
+-- Species-level passive and death-triggered abilities layered on top of the
+-- generic AI behaviours in ai.lua. Declared per species in Monsters.species
+-- so a bestiary entry fully describes what a creature does, not just how
+-- hard it hits or how it moves.
+
+local Status = require("status")
+local Items = require("items")
+local Los = require("los")
+local Combat = require("combat")
+local Durability = require("durability")
+local Momentum = require("momentum")
+
+local Abilities = {}
+
+-- Regeneration: heals `monster.regen` hp at the start of its turn, unless it
+-- is actively burning - fire cauterizes the wound faster than it closes.
+-- Runs after Status.tick so a fresh burn this same turn still suppresses it.
+function Abilities.regenTick(monster)
+  local amount = monster.regen
+  if not amount or not monster:isAlive() then return nil end
+  if Status.has(monster, Status.BURNING) then return nil end
+  local before = monster.hp
+  monster.hp = math.min(monster.maxHp, monster.hp + amount)
+  if monster.hp == before then return nil end
+  return string.format("%s knits its wounds for %d", monster.name, monster.hp - before)
+end
+
+-- On-death bursts: some species release a parting effect on whatever is
+-- adjacent to their corpse - including the player - the instant they die.
+-- Keyed by the `onDeath` tag on the species, run from Game:awardKill so the
+-- burst fires no matter what finished the monster off (melee, spell, thrown
+-- weapon, or a status effect ticking it down).
+local bursts = {
+  spores = function(game, monster)
+    local hit = {}
+    local targets = { game.player }
+    for _, other in ipairs(game:currentEntities()) do targets[#targets + 1] = other end
+    for _, victim in ipairs(targets) do
+      if victim ~= monster and victim:isAlive()
+        and math.abs(victim.x - monster.x) <= 1 and math.abs(victim.y - monster.y) <= 1 then
+        Status.apply(victim, Status.POISON, 4, 2)
+        hit[#hit + 1] = victim.name
+      end
+    end
+    if #hit == 0 then return nil end
+    return string.format("a burst of spores poisons %s", table.concat(hit, ", "))
+  end,
+}
+
+function Abilities.onDeath(game, monster)
+  local burst = monster.onDeath and bursts[monster.onDeath]
+  if not burst then return nil end
+  return burst(game, monster)
+end
+
+-- Turn-start special abilities, keyed by the `ability` tag on the species
+-- (Monsters.species) and stamped onto the entity at creation. Abilities.tryAct
+-- runs from Game:takeMonsterTurn BEFORE the plain ai.lua behaviour: when it
+-- fires it consumes the whole turn and the caller must skip Ai.act; when it
+-- returns false the monster falls through to its ordinary ai tag unchanged.
+-- Range/cooldown constants live here, not on the species, mirroring how
+-- `bursts` above centralises onDeath behaviour by tag rather than by species.
+
+local RANGE = { summon = 6, curse = 5, heal = 5, shriek = 5 }
+local COOLDOWN = { summon = 6, curse = 4, heal = 5, rally = 8, shriek = 6 }
+local MAX_SUMMONED = 2
+
+local EIGHT_DIRS = {
+  { 1, 0 }, { -1, 0 }, { 0, 1 }, { 0, -1 },
+  { 1, 1 }, { 1, -1 }, { -1, 1 }, { -1, -1 },
+}
+
+-- The first free, unoccupied, walkable cell next to (x, y), scanning a fixed
+-- direction order so results are deterministic for a given map state.
+local function freeAdjacent(game, x, y)
+  for _, dir in ipairs(EIGHT_DIRS) do
+    local nx, ny = x + dir[1], y + dir[2]
+    if game.level.map:isWalkable(nx, ny) and not game.level:entityAt(nx, ny)
+      and not (nx == game.player.x and ny == game.player.y) then
+      return nx, ny
+    end
+  end
+  return nil
+end
+
+function Abilities.tickCooldown(monster)
+  if monster.cooldown and monster.cooldown > 0 then
+    monster.cooldown = monster.cooldown - 1
+  end
+end
+
+-- Necromancer-style ability: raises a fresh minion of `summonSpecies` beside
+-- itself, tagged `summonedBy` so the population cap only counts its own brood.
+local function trySummon(game, monster)
+  if not game:canSeePlayer(monster, RANGE.summon) then return false end
+  local count = 0
+  for _, other in ipairs(game.level.entities) do
+    if other:isAlive() and other.summonedBy == monster.id then count = count + 1 end
+  end
+  if count >= MAX_SUMMONED then return false end
+  local x, y = freeAdjacent(game, monster.x, monster.y)
+  if not x then return false end
+  local minion = game:spawnMinion(monster.summonSpecies, x, y)
+  minion.summonedBy = monster.id
+  monster.cooldown = COOLDOWN.summon
+  return true, string.format("%s calls forth a %s", monster.name, minion.name)
+end
+
+-- Shaman-style ability: a ranged bolt that both hurts and weakens the player,
+-- withheld at point-blank range so the caster's ai (flee) kites instead. The
+-- hurt half runs through the exact same Combat.damage the melee/shoot paths
+-- use - mitigated by the player's defense and resistances, breaking Momentum
+-- (see momentum.lua's own "claw, breath or ambush" wording - a curse bolt is
+-- none of those by name but is that in shape) and wearing armor exactly like
+-- monsterShoot's breath already does - rather than a flat, unmitigated
+-- subtraction none of that pipeline ever saw.
+local function tryCurse(game, monster)
+  if game:playerAdjacent(monster) then return false end
+  if not game:canSeePlayer(monster, RANGE.curse) or not game:hasClearShot(monster) then
+    return false
+  end
+  local dealt = Combat.damage(monster, game.player, 1)
+  game.player.hp = game.player.hp - dealt
+  Momentum.onDamaged(game.player)
+  local broke = Durability.wearArmor(game.player)
+  if broke then game.log:add(broke) end
+  Status.apply(game.player, Status.WEAKEN, 6, 3)
+  monster.cooldown = COOLDOWN.curse
+  return true, string.format("%s curses you for %d", monster.name, dealt)
+end
+
+-- Banshee-style ability: a ranged wail that blinds instead of hurting,
+-- withheld point-blank exactly like tryCurse so the caster's own "flee" ai
+-- keeps it at kiting distance rather than trading blows. Status.BLIND
+-- (game.lua's Game:effectiveRadius) was previously only ever inflicted BY
+-- the player - a thrown potion, the blind spell, or a shared trap effect -
+-- never the other way around; this is the first hostile source of it, the
+-- same gap tryShriek's sibling "curse" would leave for WEAKEN if a monster
+-- could apply it but nothing here ever did. Duration outlasts the cooldown
+-- by one turn on purpose (5 vs 6) so a banshee left free to keep casting
+-- keeps you blind almost the whole encounter but not with zero window - the
+-- one turn of clear sight between wails is a player's chance to reposition
+-- or close the distance before the next howl lands.
+local function tryShriek(game, monster)
+  if game:playerAdjacent(monster) then return false end
+  if not game:canSeePlayer(monster, RANGE.shriek) or not game:hasClearShot(monster) then
+    return false
+  end
+  Status.apply(game.player, Status.BLIND, 5, 1)
+  monster.cooldown = COOLDOWN.shriek
+  return true, string.format("%s's wail blinds you", monster.name)
+end
+
+-- Cleric-style ability: mends the neediest hurt ally within range and line of
+-- sight instead of attacking. Ties break on the lowest hp fraction. Filtered
+-- to other.kind == "monster" - the same "hostile" tag every other module
+-- (companions.lua/mercenaries.lua/reanimation.lua's own nearestHostile,
+-- commands.lua's isVisibleHostile) already keys off of - so a dark cleric
+-- mends a fellow monster, never the player's own wounded companion, hireling
+-- or thrall sharing the same entities list.
+local function tryHeal(game, monster)
+  local best, bestRatio = nil, 1
+  for _, other in ipairs(game.level.entities) do
+    if other ~= monster and other.kind == "monster" and other:isAlive() and other.hp < other.maxHp then
+      local dist = math.max(math.abs(other.x - monster.x), math.abs(other.y - monster.y))
+      if dist <= RANGE.heal and Los.clear(game.level.map, monster.x, monster.y, other.x, other.y) then
+        local ratio = other.hp / other.maxHp
+        if ratio < bestRatio then bestRatio, best = ratio, other end
+      end
+    end
+  end
+  if not best then return false end
+  local amount = 6
+  local before = best.hp
+  best.hp = math.min(best.maxHp, best.hp + amount)
+  monster.cooldown = COOLDOWN.heal
+  return true, string.format("%s mends %s for %d", monster.name, best.name, best.hp - before)
+end
+
+-- Chieftain-style ability: grants every adjacent, not-yet-buffed ally (and
+-- itself) a temporary attack boost. No-op once the whole knot is already lit.
+-- Filtered to other.kind == "monster" for the same reason tryHeal above is:
+-- without it a chieftain standing next to the player's companion, hireling
+-- or thrall would rally that ally of the PLAYER's instead of one of its own.
+local function tryRally(game, monster)
+  local buffed = {}
+  for _, other in ipairs(game.level.entities) do
+    if other ~= monster and other.kind == "monster" and other:isAlive() and not Status.has(other, Status.STRENGTH)
+      and math.abs(other.x - monster.x) <= 1 and math.abs(other.y - monster.y) <= 1 then
+      Status.apply(other, Status.STRENGTH, 10, 2)
+      buffed[#buffed + 1] = other.name
+    end
+  end
+  if #buffed == 0 then return false end
+  Status.apply(monster, Status.STRENGTH, 10, 2)
+  monster.cooldown = COOLDOWN.rally
+  return true, string.format("%s rallies %s", monster.name, table.concat(buffed, ", "))
+end
+
+-- Footpad-style ability: not cooldown-gated. Once adjacent it lifts a single
+-- non-essential item (never an equipped key or the amulet, since those never
+-- sit unequipped in inventory) and flees for the rest of the encounter; a
+-- fleeing footpad just keeps running rather than trying again.
+local function trySteal(game, monster)
+  if monster.fleeing then
+    game:stepMonsterAway(monster, game.player.x, game.player.y)
+    return true
+  end
+  if not game:playerAdjacent(monster) then return false end
+  local idx = game:findInInventory(function(item)
+    return item.kind ~= Items.KEY and item.kind ~= Items.AMULET
+  end)
+  if not idx then
+    monster.fleeing = true
+    return true, string.format("%s finds nothing worth stealing and flees", monster.name)
+  end
+  local item = table.remove(game.player.inventory, idx)
+  monster.stolen = item
+  monster.fleeing = true
+  return true, string.format("%s steals your %s and flees", monster.name, item.name)
+end
+
+local dispatch = { summon = trySummon, curse = tryCurse, heal = tryHeal, rally = tryRally, shriek = tryShriek }
+
+-- Called once per monster turn, after status ticks and regen but before
+-- ai.lua. Returns true when the ability consumed the turn.
+function Abilities.tryAct(game, monster)
+  if not monster.ability then return false end
+  if monster.ability == "steal" then
+    local acted, line = trySteal(game, monster)
+    if acted and line then game.log:add(line) end
+    return acted == true
+  end
+  local handler = dispatch[monster.ability]
+  if not handler or (monster.cooldown and monster.cooldown > 0) then return false end
+  local acted, line = handler(game, monster)
+  if not acted then return false end
+  if line then game.log:add(line) end
+  return true
+end
+
+-- Slime-style reaction: fired from Game:playerAttack when a hit lands but
+-- does not kill. Halves the victim's max hp and spawns a clone at the other
+-- half, capped at two splits total (`splitGen`) so a slime cannot be farmed
+-- into an unbounded swarm.
+function Abilities.onHit(game, target)
+  if target.ability ~= "split" then return nil end
+  if not target:isAlive() or target.maxHp < 4 then return nil end
+  if (target.splitGen or 0) >= 2 then return nil end
+  local x, y = freeAdjacent(game, target.x, target.y)
+  if not x then return nil end
+  local newMax = target.maxHp // 2
+  target.maxHp = newMax
+  target.hp = math.min(target.hp, newMax)
+  target.splitGen = (target.splitGen or 0) + 1
+  local clone = game:spawnMinion(target.species, x, y)
+  clone.maxHp = newMax
+  clone.hp = newMax
+  clone.splitGen = target.splitGen
+  return string.format("the %s splits in two", target.name)
+end
+
+return Abilities

src/affixes.lua

@@ -1,14 +1,18 @@
 -- Gear affixes. A weapon or armour piece may roll a prefix that bumps its power
 -- and, for some weapons, attaches an on-hit rider (e.g. flaming sets the target
 -- alight). Rolls draw from the shared rng so drops stay deterministic per seed.
+-- An elemental rider also retags the weapon's own base swing (damageType,
+-- read by combat.lua) to match - a flaming sword fights with fire, not steel,
+-- so it hits harder against a cold-weak target and can do nothing at all
+-- against something fire-immune.
 
 local Affixes = {}
 
 Affixes.weapon = {
   { key = "sharp",   name = "sharp",   power = 1 },
   { key = "vicious", name = "vicious", power = 2 },
-  { key = "flaming", name = "flaming", power = 1, onHit = { status = "burning", duration = 3, potency = 2 } },
-  { key = "venomed", name = "venomed", power = 0, onHit = { status = "poison",  duration = 4, potency = 1 } },
+  { key = "flaming", name = "flaming", power = 1, onHit = { status = "burning", duration = 3, potency = 2 }, damageType = "fire" },
+  { key = "venomed", name = "venomed", power = 0, onHit = { status = "poison",  duration = 4, potency = 1 }, damageType = "poison" },
 }
 
 Affixes.armor = {
@@ -31,9 +35,10 @@ end
 
 function Affixes.decorate(item, affix)
   if not affix then return item end
-  item.affix = { key = affix.key, name = affix.name, power = affix.power, onHit = affix.onHit }
+  item.affix = { key = affix.key, name = affix.name, power = affix.power, onHit = affix.onHit, damageType = affix.damageType }
   item.power = item.power + affix.power
   item.name = affix.name .. " " .. item.name
+  item.damageType = affix.damageType
   return item
 end
 

src/ai.lua

@@ -2,15 +2,38 @@
 -- resolves that monster's turn through game helpers, so all state mutation and
 -- rng use stays centralised and deterministic.
 
+local Status = require("status")
+local Infighting = require("infighting")
+
 local Ai = {}
 
-local AGGRO = { chase = 10, pack = 13, ranged = 12, flee = 8, erratic = 8 }
+local AGGRO = { chase = 10, pack = 13, ranged = 12, flee = 8, erratic = 8, tunnel = 10 }
 local DIRS = { { 1, 0 }, { -1, 0 }, { 0, 1 }, { 0, -1 } }
 
+-- A player-aligned ally standing adjacent to `monster` occupies its cell
+-- exactly the way a wall would for Game:stepMonsterToward's own pathfinding
+-- (blockedForMonster treats any occupied non-goal cell as impassable) - so a
+-- one-wide corridor an ally is plugging leaves every pursuit behaviour below
+-- with no route at all, and without this check they simply idle beside it
+-- forever rather than fighting the living combatant in their way. Resolves
+-- through Infighting.strike, the same generic monster-vs-any-creature combat
+-- infighting.lua already uses for rivalries and discord. Returns true once
+-- it has spent the monster's turn this way, so each caller can bail out at
+-- the same priority Game:playerAdjacent already has over closing distance.
+local function attackBlockingAlly(game, monster)
+  local ally = game:adjacentAlly(monster)
+  if not ally then return false end
+  Infighting.strike(game, monster, ally)
+  return true
+end
+
 local function chase(game, monster)
   if game:playerAdjacent(monster) then
     game:monsterMelee(monster)
-  elseif game:canSeePlayer(monster, AGGRO.chase) then
+    return
+  end
+  if attackBlockingAlly(game, monster) then return end
+  if game:canSeePlayer(monster, AGGRO.chase) then
     game:stepMonsterToward(monster, game.player.x, game.player.y)
   end
 end
@@ -20,6 +43,7 @@ local function pack(game, monster)
     game:monsterMelee(monster)
     return
   end
+  if attackBlockingAlly(game, monster) then return end
   if game:canSeePlayer(monster, AGGRO.pack) then
     game:stepMonsterToward(monster, game.player.x, game.player.y)
     return
@@ -39,6 +63,7 @@ local function ranged(game, monster)
     end
     return
   end
+  if attackBlockingAlly(game, monster) then return end
   if game:canSeePlayer(monster, AGGRO.ranged) then
     game:stepMonsterToward(monster, game.player.x, game.player.y)
   end
@@ -50,6 +75,14 @@ local function flee(game, monster)
   end
 end
 
+-- Shopkeepers idle unless game.lua has already flagged them hostile (a theft
+-- from their stock), at which point they behave exactly like a chaser.
+local function vend(game, monster)
+  if monster.hostile then
+    chase(game, monster)
+  end
+end
+
 local function erratic(game, monster)
   if game:playerAdjacent(monster) then
     game:monsterMelee(monster)
@@ -63,15 +96,45 @@ local function erratic(game, monster)
   end
 end
 
+-- A burrower: melee once adjacent, chase like anything else once it can see
+-- the player through open floor, otherwise claw straight through whatever
+-- rock stands between them (see Game:monsterDig, digging.lua) rather than
+-- idling the way a plain chaser out of sight would.
+local function tunnel(game, monster)
+  if game:playerAdjacent(monster) then
+    game:monsterMelee(monster)
+    return
+  end
+  if attackBlockingAlly(game, monster) then return end
+  if game:canSeePlayer(monster, AGGRO.tunnel) then
+    game:stepMonsterToward(monster, game.player.x, game.player.y)
+    return
+  end
+  game:monsterDig(monster, game.player.x, game.player.y)
+end
+
 Ai.behaviours = {
   chase = chase,
   pack = pack,
   ranged = ranged,
   flee = flee,
   erratic = erratic,
+  vend = vend,
+  tunnel = tunnel,
 }
 
+-- A confused monster gets the exact same chance each turn to have its own
+-- chosen direction overridden that Game:movePlayer rolls for the player - see
+-- status.lua's Status.CONFUSE_NUMERATOR/DENOMINATOR, shared by both sides so
+-- neither one confuses more reliably than the other. On a lucky roll (or once
+-- confusion wears off) `behaviour` below runs completely untouched.
 function Ai.act(game, monster)
+  if Status.has(monster, Status.CONFUSE)
+    and game.rng:chance(Status.CONFUSE_NUMERATOR, Status.CONFUSE_DENOMINATOR) then
+    local dir = DIRS[game.rng:range(1, #DIRS)]
+    game:moveMonster(monster, dir[1], dir[2])
+    return
+  end
   local behaviour = Ai.behaviours[monster.ai] or chase
   behaviour(game, monster)
 end

src/alchemy.lua

@@ -0,0 +1,102 @@
+-- Herb-based potion brewing, layered on top of items.lua's existing potion
+-- catalog rather than inventing a second one: a cauldron turns two foraged
+-- herbs into the same potions rollItem already scatters as loot, so a
+-- brewed potion drinks, throws (throwing.lua) and identifies exactly like a
+-- found one. Recipes are fixed data, the same way crafting.lua's elemental
+-- riders are fixed - the uncertainty here is not "what does this pair do"
+-- but whether two ill-matched herbs curdle instead of brewing cleanly. See
+-- Game:brewAt for how a curdle is resolved against the brewer.
+
+local Items = require("items")
+
+local Alchemy = {}
+
+Alchemy.SUNPETAL = "sunpetal"
+Alchemy.BLOODROOT = "bloodroot"
+Alchemy.EMBERLEAF = "emberleaf"
+Alchemy.FROSTMOSS = "frostmoss"
+Alchemy.NIGHTCAP = "nightcap"
+Alchemy.MOONBELL = "moonbell"
+
+-- Fixed order so a given rng draw always names the same herb. New herbs
+-- append at the end (see builder.lua's own comment on Alchemy.order) so an
+-- existing seed's earlier picks never change which herb they name.
+Alchemy.order = {
+  Alchemy.BLOODROOT, Alchemy.EMBERLEAF, Alchemy.FROSTMOSS, Alchemy.NIGHTCAP, Alchemy.SUNPETAL,
+  Alchemy.MOONBELL,
+}
+
+Alchemy.names = {
+  [Alchemy.SUNPETAL] = "sunpetal",
+  [Alchemy.BLOODROOT] = "bloodroot",
+  [Alchemy.EMBERLEAF] = "emberleaf",
+  [Alchemy.FROSTMOSS] = "frostmoss",
+  [Alchemy.NIGHTCAP] = "nightcap",
+  [Alchemy.MOONBELL] = "moonbell",
+}
+
+local CURDLE = { curdle = true }
+
+-- Canonical order-independent key for a herb pair: the two herb keys sorted
+-- and joined, so brewing (A, B) and (B, A) always land on the same recipe.
+local function pairKey(a, b)
+  if a > b then a, b = b, a end
+  return a .. "+" .. b
+end
+Alchemy.pairKey = pairKey
+
+-- Same-herb pairs concentrate that herb's own aspect; cross pairs blend two
+-- aspects into a shared potion, except the pairings whose aspects outright
+-- oppose each other (light versus shade, fire versus frost, day versus
+-- dream), which curdle instead of brewing.
+Alchemy.recipes = {
+  [pairKey(Alchemy.SUNPETAL, Alchemy.SUNPETAL)] = { effect = "heal", power = 18 },
+  [pairKey(Alchemy.SUNPETAL, Alchemy.BLOODROOT)] = { effect = "heal", power = 10 },
+  [pairKey(Alchemy.SUNPETAL, Alchemy.EMBERLEAF)] = { effect = "haste" },
+  [pairKey(Alchemy.SUNPETAL, Alchemy.FROSTMOSS)] = { effect = "fortify" },
+  [pairKey(Alchemy.SUNPETAL, Alchemy.NIGHTCAP)] = CURDLE,
+  [pairKey(Alchemy.BLOODROOT, Alchemy.BLOODROOT)] = { effect = "strength" },
+  [pairKey(Alchemy.BLOODROOT, Alchemy.EMBERLEAF)] = { effect = "strength" },
+  [pairKey(Alchemy.BLOODROOT, Alchemy.FROSTMOSS)] = { effect = "fortify" },
+  [pairKey(Alchemy.BLOODROOT, Alchemy.NIGHTCAP)] = { effect = "poison", power = 4 },
+  [pairKey(Alchemy.EMBERLEAF, Alchemy.EMBERLEAF)] = { effect = "haste" },
+  [pairKey(Alchemy.EMBERLEAF, Alchemy.FROSTMOSS)] = CURDLE,
+  [pairKey(Alchemy.EMBERLEAF, Alchemy.NIGHTCAP)] = { effect = "poison", power = 5 },
+  [pairKey(Alchemy.FROSTMOSS, Alchemy.FROSTMOSS)] = { effect = "fortify" },
+  [pairKey(Alchemy.FROSTMOSS, Alchemy.NIGHTCAP)] = { effect = "poison", power = 5 },
+  [pairKey(Alchemy.NIGHTCAP, Alchemy.NIGHTCAP)] = { effect = "poison", power = 7 },
+  -- Moonbell's own aspect is dream-fog, so concentrating it addles the
+  -- brewer's own mind rather than anyone else's - the same "own aspect
+  -- turned inward" shape as every other same-herb pair above. Sunlight is
+  -- the one aspect it outright opposes (wakeful day versus dreaming night,
+  -- the same shape as sunpetal/nightcap's light-versus-shade curdle above),
+  -- so that pairing curdles instead of brewing.
+  [pairKey(Alchemy.MOONBELL, Alchemy.MOONBELL)] = { effect = "confuse" },
+  [pairKey(Alchemy.SUNPETAL, Alchemy.MOONBELL)] = CURDLE,
+  [pairKey(Alchemy.BLOODROOT, Alchemy.MOONBELL)] = { effect = "clarity" },
+  [pairKey(Alchemy.EMBERLEAF, Alchemy.MOONBELL)] = { effect = "blind" },
+  [pairKey(Alchemy.FROSTMOSS, Alchemy.MOONBELL)] = { effect = "levitate" },
+  [pairKey(Alchemy.NIGHTCAP, Alchemy.MOONBELL)] = { effect = "poison", power = 6 },
+}
+
+function Alchemy.herb(key)
+  return { kind = Items.HERB, herb = key, name = Alchemy.names[key] .. " herb", glyph = ";" }
+end
+
+-- The fixed outcome for brewing herbA with herbB together, order
+-- independent. Returns nil only when either key names no known herb.
+function Alchemy.lookup(herbA, herbB)
+  if not Alchemy.names[herbA] or not Alchemy.names[herbB] then return nil end
+  return Alchemy.recipes[pairKey(herbA, herbB)]
+end
+
+-- Resolves a completed brew into a fresh potion item, or (nil, "curdle") for
+-- an opposed pairing - the caller decides what a curdle does to the brewer.
+function Alchemy.brew(herbA, herbB)
+  local recipe = Alchemy.lookup(herbA, herbB)
+  if not recipe then return nil, "unknown herb" end
+  if recipe.curdle then return nil, "curdle" end
+  return Items.potionOf(recipe.effect, recipe.power)
+end
+
+return Alchemy

src/analytics.lua

@@ -0,0 +1,58 @@
+-- Aggregate, read-only statistics over meta.lua's own cross-run history:
+-- how often a body of runs actually won, which class shows up most among
+-- them, and where a fresh score would land against that history - three
+-- questions renown and achievements never answer on their own, since both
+-- only ever look at the one run in front of them, never the shape of every
+-- run that came before it.
+
+local Analytics = {}
+
+-- Fraction of recorded runs that ended in victory. 0 for a state that has
+-- not recorded any runs yet rather than dividing by zero.
+function Analytics.winRate(meta)
+  if meta.totalRuns == 0 then return 0 end
+  return meta.wins / meta.totalRuns
+end
+
+-- Mean score across every leaderboard entry (see leaderboard.lua), 0 for an
+-- empty board.
+function Analytics.averageScore(board)
+  if #board == 0 then return 0 end
+  local total = 0
+  for _, entry in ipairs(board) do total = total + entry.score end
+  return total / #board
+end
+
+-- The className appearing most often on `board`, ties broken toward
+-- whichever class was seen first on the board - so the answer only ever
+-- depends on the board's own entry order, never on however pairs() happens
+-- to walk a count table. nil for an empty board.
+function Analytics.favoriteClass(board)
+  local counts, order = {}, {}
+  for _, entry in ipairs(board) do
+    if not counts[entry.className] then order[#order + 1] = entry.className end
+    counts[entry.className] = (counts[entry.className] or 0) + 1
+  end
+  local best, bestCount = nil, 0
+  for _, className in ipairs(order) do
+    if counts[className] > bestCount then
+      best, bestCount = className, counts[className]
+    end
+  end
+  return best
+end
+
+-- How many of `board`'s entries `score` would actually outrank, as a
+-- fraction from 0 (worse than or tied with everything) to 1 (better than
+-- everything). An empty board always answers 1 - there is nothing left to
+-- beat, so nothing holds the score back.
+function Analytics.percentile(board, score)
+  if #board == 0 then return 1 end
+  local beaten = 0
+  for _, entry in ipairs(board) do
+    if score > entry.score then beaten = beaten + 1 end
+  end
+  return beaten / #board
+end
+
+return Analytics

src/artifacts.lua

@@ -0,0 +1,133 @@
+-- Unique named gear. Unlike a rolled affix (affixes.lua), which stacks a
+-- small power bump onto an ordinary base item, an artifact is a fixed,
+-- always-on mechanic attached to a fixed item - lifesteal, thorns, a passive
+-- regen aura, an armour-ignoring shot. Artifacts are never masked by
+-- identification: identify.isConcealable only conceals potions and scrolls,
+-- so a found artifact shows its real name and effect immediately.
+--
+-- Builder places at most one per floor from depth 5 on, its rarity roll
+-- appended after every other placement (see builder.lua) so it can never
+-- perturb an earlier system's rng sequence. Per-floor rng is independent
+-- (dungeon.lua reseeds fresh per depth), so this is a per-floor rarity, not a
+-- tracked one-per-run guarantee the way the amulet is.
+
+local Items = require("items")
+
+local Artifacts = {}
+
+Artifacts.LIFESTEAL = "lifesteal"
+Artifacts.THORNS = "thorns"
+Artifacts.REGEN = "regen"
+Artifacts.PIERCING = "piercing"
+
+Artifacts.catalog = {
+  {
+    key = "bloodfang", slot = "weapon", name = "Bloodfang", power = 4,
+    unique = Artifacts.LIFESTEAL, value = 0.5,
+  },
+  {
+    key = "aegis_of_embers", slot = "armor", name = "Aegis of Embers", power = 2,
+    unique = Artifacts.THORNS, value = 0.5,
+  },
+  {
+    key = "ring_of_the_tide", slot = "ring", name = "Ring of the Tide", attack = 1, defense = 1,
+    unique = Artifacts.REGEN, value = 2,
+  },
+  {
+    key = "gale_bow", slot = "bow", name = "Gale Bow", power = 3, range = 6,
+    unique = Artifacts.PIERCING, value = 3,
+  },
+  {
+    key = "cinderplate", slot = "armor", name = "Cinderplate", power = 2,
+    resist = { fire = "resist" },
+  },
+  {
+    key = "frostband", slot = "ring", name = "Frostband", attack = 0, defense = 1,
+    resist = { cold = "resist" },
+  },
+
+  -- Boss-exclusive drops (bosses.lua): stronger versions of an existing
+  -- unique mechanic, flagged bossOnly so the loop below keeps them out of
+  -- Artifacts.order and therefore out of builder.lua's ordinary per-floor
+  -- roll. The only way to obtain one is felling the boss that guarantees it.
+  {
+    key = "warlords_cleaver", slot = "weapon", name = "the Warlord's Cleaver", power = 6,
+    unique = Artifacts.LIFESTEAL, value = 0.75, bossOnly = true,
+  },
+  {
+    key = "lich_phylactery", slot = "ring", name = "the Lich's Phylactery", attack = 1, defense = 2,
+    unique = Artifacts.REGEN, value = 4, bossOnly = true,
+  },
+  {
+    key = "bone_queen_carapace", slot = "armor", name = "the Bone Queen's Carapace", power = 4,
+    unique = Artifacts.THORNS, value = 0.9, bossOnly = true,
+  },
+}
+
+Artifacts.byKey = {}
+Artifacts.order = {}
+for _, spec in ipairs(Artifacts.catalog) do
+  Artifacts.byKey[spec.key] = spec
+  if not spec.bossOnly then
+    Artifacts.order[#Artifacts.order + 1] = spec.key
+  end
+end
+
+-- Builds the dropped item for `key` in the same shape items.lua's own
+-- constructors return for that slot, tagged with the fields the equip
+-- callers below key their special-case behaviour off (`unique` and `value`).
+function Artifacts.create(key)
+  local spec = Artifacts.byKey[key]
+  if not spec then return nil end
+  local item
+  if spec.slot == "weapon" then
+    item = Items.weapon(spec.name, spec.power)
+  elseif spec.slot == "armor" then
+    item = Items.armor(spec.name, spec.power)
+  elseif spec.slot == "ring" then
+    item = Items.ring(spec.name, spec.attack, spec.defense)
+  elseif spec.slot == "bow" then
+    item = Items.bow(spec.name, spec.power, spec.range)
+  end
+  item.artifact = key
+  item.unique = spec.unique
+  item.value = spec.value
+  item.resist = spec.resist
+  return item
+end
+
+-- Hp returned to `attacker` from a lifesteal weapon's hit, or 0 without one.
+function Artifacts.lifestealAmount(attacker, damage)
+  local weapon = attacker.weapon
+  if weapon and weapon.unique == Artifacts.LIFESTEAL then
+    return math.max(1, math.floor(damage * weapon.value))
+  end
+  return 0
+end
+
+-- Damage reflected back at whoever just landed a melee hit on `defender`, or
+-- 0 without thorned armour worn.
+function Artifacts.thornsAmount(defender, damage)
+  local armor = defender.armor
+  if armor and armor.unique == Artifacts.THORNS then
+    return math.max(1, math.floor(damage * armor.value))
+  end
+  return 0
+end
+
+-- Hp `entity` regenerates this turn from a worn ring, or 0 without one.
+function Artifacts.ringRegen(entity)
+  local ring = entity.ring
+  if ring and ring.unique == Artifacts.REGEN then return ring.value end
+  return 0
+end
+
+-- Flat defense `entity`'s readied bow ignores on its next shot, or 0 without
+-- a piercing bow.
+function Artifacts.bowPierce(entity)
+  local bow = entity.bow
+  if bow and bow.unique == Artifacts.PIERCING then return bow.value end
+  return 0
+end
+
+return Artifacts

src/ascension.lua

@@ -0,0 +1,136 @@
+-- Optional run-wide difficulty mutators a player opts into before a run
+-- starts, in exchange for extra renown once it ends: risk taken on purpose,
+-- unlike events.lua's mutators which fire and fade on their own mid-run
+-- regardless of anyone's choice. A mutator unlocks once meta.lua's own
+-- cross-run tallies (best depth, wins) cross its fixed requirement -
+-- computed live off those tallies rather than persisted, since both only
+-- ever climb, so nothing here needs its own entry in meta.lua's save shape.
+--
+-- Active mutators for the run in progress live on game.ascension, a plain
+-- array of keys in catalog order (see Ascension.resolve), exactly the shape
+-- warren.lua's --mutators flag builds. Plain data, so it serializes with no
+-- special save-format handling, and every combat/essence/sight hook that
+-- reads it (Game:monsterDamageMultiplier, Game:essenceMultiplier,
+-- Game:effectiveRadius) stays a pure function of that array alongside
+-- whatever level-scoped event Events.lua itself is contributing.
+
+local Ascension = {}
+
+Ascension.MUTATORS = {
+  { key = "bloodbound", name = "Bloodbound", desc = "monsters hit 50% harder",
+    renownBonus = 15, requiresDepth = 3, requiresWins = 0, damageMultiplier = 1.5 },
+  { key = "famine", name = "Famine", desc = "essence income halved",
+    renownBonus = 10, requiresDepth = 2, requiresWins = 0, essenceMultiplier = 0.5 },
+  { key = "nightblind", name = "Nightblind", desc = "sight radius reduced by 2",
+    renownBonus = 10, requiresDepth = 2, requiresWins = 0, sightPenalty = 2 },
+  { key = "frail", name = "Frail", desc = "defense halved",
+    renownBonus = 12, requiresDepth = 4, requiresWins = 0,
+    applyToPlayer = function(player)
+      player.baseDefense = player.baseDefense // 2
+      player.defense = player.defense // 2
+    end },
+  { key = "glasscannon", name = "Glass Cannon", desc = "max hp halved, attack doubled",
+    renownBonus = 20, requiresDepth = 0, requiresWins = 1,
+    applyToPlayer = function(player)
+      player.maxHp = math.max(1, player.maxHp // 2)
+      player.hp = math.min(player.hp, player.maxHp)
+      player.baseAttack = player.baseAttack * 2
+      player.attack = player.attack * 2
+    end },
+}
+
+Ascension.byKey = {}
+Ascension.order = {}
+for _, def in ipairs(Ascension.MUTATORS) do
+  Ascension.byKey[def.key] = def
+  Ascension.order[#Ascension.order + 1] = def.key
+end
+
+-- A meta-less caller (no --meta flag at all) can still activate whatever
+-- costs nothing to unlock; every other mutator needs a persistent meta file
+-- to have already banked the depth or win it requires.
+function Ascension.isUnlocked(meta, key)
+  local def = Ascension.byKey[key]
+  if not def then return false end
+  if not meta then return def.requiresDepth == 0 and def.requiresWins == 0 end
+  return meta.bestDepth >= def.requiresDepth and meta.wins >= def.requiresWins
+end
+
+-- Validates a requested list of mutator keys against both the catalog and
+-- `meta`'s own unlock state, returned de-duplicated in catalog order rather
+-- than whatever order the caller supplied - so two runs activating the same
+-- set always see it identically regardless of how --mutators listed them.
+-- An unknown or still-locked key is silently dropped rather than failing
+-- the whole run over one bad flag.
+function Ascension.resolve(meta, requested)
+  if not requested or #requested == 0 then return {} end
+  local wanted = {}
+  for _, key in ipairs(requested) do wanted[key] = true end
+  local active = {}
+  for _, key in ipairs(Ascension.order) do
+    if wanted[key] and Ascension.isUnlocked(meta, key) then
+      active[#active + 1] = key
+    end
+  end
+  return active
+end
+
+function Ascension.isActive(active, key)
+  for _, k in ipairs(active or {}) do
+    if k == key then return true end
+  end
+  return false
+end
+
+function Ascension.damageMultiplier(active)
+  local mult = 1
+  for _, key in ipairs(active or {}) do
+    local def = Ascension.byKey[key]
+    if def and def.damageMultiplier then mult = mult * def.damageMultiplier end
+  end
+  return mult
+end
+
+function Ascension.essenceMultiplier(active)
+  local mult = 1
+  for _, key in ipairs(active or {}) do
+    local def = Ascension.byKey[key]
+    if def and def.essenceMultiplier then mult = mult * def.essenceMultiplier end
+  end
+  return mult
+end
+
+function Ascension.sightPenalty(active)
+  local penalty = 0
+  for _, key in ipairs(active or {}) do
+    local def = Ascension.byKey[key]
+    if def and def.sightPenalty then penalty = penalty + def.sightPenalty end
+  end
+  return penalty
+end
+
+-- Renown bonus percentage this active set adds on top of Meta.renownFor's
+-- own base score, summed rather than compounded - three 15% mutators add
+-- 45%, not a runaway 1.15^3 - so stacking more of them is always a
+-- straightforward trade of more risk for more reward.
+function Ascension.renownBonusPercent(active)
+  local percent = 0
+  for _, key in ipairs(active or {}) do
+    local def = Ascension.byKey[key]
+    if def then percent = percent + def.renownBonus end
+  end
+  return percent
+end
+
+-- Applies every active mutator's one-time player-stat delta, in catalog
+-- order. Meant to run once in Game.new, after Meta.applyAll's perks and any
+-- class delta, since a mutator is the final, voluntary layer of difficulty
+-- stacked on top of whatever build the player already chose.
+function Ascension.applyToPlayer(active, player)
+  for _, key in ipairs(active or {}) do
+    local def = Ascension.byKey[key]
+    if def and def.applyToPlayer then def.applyToPlayer(player) end
+  end
+end
+
+return Ascension

src/atmosphere.lua

@@ -0,0 +1,49 @@
+-- Floor-wide weather: a single condition drawn once at generation (like
+-- `dark`) that colors the whole level rather than one cell of it. Unlike
+-- terrain.lua's per-tile hazards (lava, chasm, ice), a floor's weather has no
+-- position of its own - every numeric hook below is a flat, floor-lifetime
+-- modifier the caller applies once per turn or once at generation, never
+-- something a player can step in or out of.
+
+local Atmosphere = {}
+
+Atmosphere.FOGGY = "foggy"
+Atmosphere.CONSECRATED = "consecrated"
+Atmosphere.INFESTED = "infested"
+
+-- Fixed order so a given rng draw always names the same condition.
+Atmosphere.order = { Atmosphere.FOGGY, Atmosphere.CONSECRATED, Atmosphere.INFESTED }
+
+-- A thick, clinging fog: everyone's sight radius shrinks, monsters and traps
+-- included, before the darkness/torch radius in Game:effectiveRadius is
+-- even considered.
+function Atmosphere.sightPenalty(weather)
+  if weather == Atmosphere.FOGGY then return 2 end
+  return 0
+end
+
+-- Consecrated ground mends the living each turn they linger on it, exactly
+-- like an artifact's fixed regen (see artifacts.ringRegen) but floor-wide
+-- and free of any equipment.
+function Atmosphere.regenBonus(weather)
+  if weather == Atmosphere.CONSECRATED then return 1 end
+  return 0
+end
+
+-- An infested floor's monsters hit harder from the moment they are placed -
+-- a flat, permanent bump baked into their stats at generation time (see
+-- builder.lua), the same way an elite affix or a boss's own catalog entry
+-- already sets a monster's power once and for all.
+function Atmosphere.monsterAttackBonus(weather)
+  if weather == Atmosphere.INFESTED then return 2 end
+  return 0
+end
+
+function Atmosphere.describe(weather)
+  if weather == Atmosphere.FOGGY then return "a thick fog blankets this floor" end
+  if weather == Atmosphere.CONSECRATED then return "this floor is consecrated ground" end
+  if weather == Atmosphere.INFESTED then return "this floor teems with infestation" end
+  return nil
+end
+
+return Atmosphere

src/biomes.lua

@@ -0,0 +1,62 @@
+-- Depth-band environmental theme layered on top of the systems that already
+-- read raw depth alone: unlike atmosphere.lua's weather (a coin flip drawn
+-- fresh on every floor from depth two on, see Atmosphere.order), a biome is
+-- a fixed function of depth by itself, so floor three always belongs to the
+-- same people and the same climate no matter which seed generated it -
+-- weather is what a given run of that floor happens to be like today, a
+-- biome is what the floor always is. Each entry names the faction that
+-- actually lives there (see factions.lua) and the hazard kind its climate
+-- tends toward (see hazards.lua), which the builder's biome pass - appended
+-- dead last of all in Builder.build, after even the grave, so it can never
+-- perturb any earlier system's rng sequence - may draw on to reinforce a
+-- floor with one more native monster or bloom a small pocket of that
+-- hazard, strictly on top of everything already placed there.
+
+local Factions = require("factions")
+local Hazards = require("hazards")
+
+local Biomes = {}
+
+Biomes.CATALOG = {
+  { key = "warrens",  name = "the mossy warrens",  favoredFaction = Factions.VERMIN,    hazardKind = Hazards.GAS,  ambient = "damp stone and skittering claws" },
+  { key = "burrows",  name = "the goblin burrows", favoredFaction = Factions.GOBLINOID, hazardKind = Hazards.GAS,  ambient = "crude tunnels reeking of tallow smoke" },
+  { key = "crypts",   name = "the sunken crypts",  favoredFaction = Factions.UNDEAD,    hazardKind = Hazards.GAS,  ambient = "cold air thick with grave rot" },
+  { key = "warcamp",  name = "the orcish warcamp", favoredFaction = Factions.ORCISH,    hazardKind = Hazards.FIRE, ambient = "smoke-stained banners and cookfires" },
+  { key = "sanctum",  name = "the cult sanctum",   favoredFaction = Factions.CULT,      hazardKind = Hazards.FIRE, ambient = "chanting echoes off blood-lit stone" },
+  { key = "wyrmnest", name = "the wyrm's nest",    favoredFaction = Factions.DRAKE,     hazardKind = Hazards.FIRE, ambient = "scorched walls and the reek of sulfur" },
+}
+
+Biomes.byKey = {}
+for _, biome in ipairs(Biomes.CATALOG) do
+  Biomes.byKey[biome.key] = biome
+end
+
+-- Cyclic by depth, exactly the way chosenGenerator above already cycles
+-- through Gen.order: a dungeon of any Builder.maxDepth wraps back through
+-- the catalog rather than running off its end once depth outgrows it.
+function Biomes.forDepth(depth)
+  return Biomes.CATALOG[((depth - 1) % #Biomes.CATALOG) + 1]
+end
+
+function Biomes.describe(biome)
+  return string.format("%s: %s", biome.name, biome.ambient)
+end
+
+-- The subset of an already depth-filtered species list (see
+-- Monsters.forDepth) that actually belongs to biome's own faction - the
+-- pool the builder's reinforcement pass draws a native from, empty whenever
+-- nothing eligible this shallow yet belongs to the biome's own people.
+-- Ranged specs are excluded outright: a second archer stacks free damage no
+-- melee approach can answer, so reinforcement only ever sends backup a
+-- player can actually close the distance on.
+function Biomes.nativesAmong(biome, eligible)
+  local natives = {}
+  for _, spec in ipairs(eligible) do
+    if spec.faction == biome.favoredFaction and spec.ai ~= "ranged" then
+      natives[#natives + 1] = spec
+    end
+  end
+  return natives
+end
+
+return Biomes

src/blocks.lua

@@ -0,0 +1,113 @@
+-- Pushable blocks: a block occupies a floor cell and blocks movement and
+-- pathing exactly like a wall, but shoving it (see Game:movePlayer) relocates
+-- it one cell in the push direction instead of just refusing the move, the
+-- same "walk into it to interact" shape a closed door or a vault lever
+-- already has. A block shoved into lava solidifies into rubble and one
+-- shoved into a chasm fills the gap into plain floor - both permanently
+-- consume the block, since it has nothing left to rest on once the hazard
+-- it corrected is gone. Shoved onto a pressure plate instead, the block
+-- survives and holds its linked gate open for as long as it stays put (see
+-- Blocks.updateGates) - unlike vaults.lua's lever, a gate reseals the
+-- instant the weight holding it open moves off the plate again.
+
+local Tiles = require("tiles")
+local Items = require("items")
+local Affixes = require("affixes")
+
+local Blocks = {}
+
+local treasureWeapons = {
+  { name = "gate-forged blade", power = 7 },
+  { name = "gate-forged maul",  power = 8 },
+}
+local treasureArmors = {
+  { name = "gate-forged plate", power = 6 },
+}
+
+-- A guaranteed affix on a base already well above anything the floor's own
+-- loot table can roll at this depth, mirroring vaults.lua's own Vaults.
+-- treasure but with names that never claim to come from a vault.
+function Blocks.treasure(rng, depth)
+  if rng:chance(1, 2) then
+    local base = treasureWeapons[rng:range(1, #treasureWeapons)]
+    local item = Items.weapon(base.name, base.power + depth // 3)
+    return Affixes.decorate(item, Affixes.weapon[rng:range(1, #Affixes.weapon)])
+  end
+  local base = treasureArmors[rng:range(1, #treasureArmors)]
+  local item = Items.armor(base.name, base.power + depth // 3)
+  return Affixes.decorate(item, Affixes.armor[rng:range(1, #Affixes.armor)])
+end
+
+-- Whether a cell a block might be shoved into can actually receive it: in
+-- bounds, not a wall, a door of any kind, or a gate, and not already host to
+-- another block or a living entity. Lava and chasm cells count as
+-- receiving even though Blocks.push special-cases what happens to them
+-- next, rather than refusing the shove outright.
+function Blocks.canReceive(level, x, y)
+  if not level.map:inBounds(x, y) then return false end
+  local tile = level.map:get(x, y)
+  if tile == Tiles.WALL or Tiles.isDoor(tile) or Tiles.isVaultDoor(tile) or Tiles.isGate(tile) then
+    return false
+  end
+  if level:blockAt(x, y) or level:entityAt(x, y) then return false end
+  return true
+end
+
+local function remove(level, block)
+  for i, b in ipairs(level.blocks) do
+    if b == block then
+      table.remove(level.blocks, i)
+      return
+    end
+  end
+end
+
+-- Shoves `block` by (dx, dy) if the far cell can receive it. Returns
+-- (true, message) on a successful shove, resolving whatever lava or chasm
+-- it lands in along the way (Blocks.remove), or (false) when the far cell
+-- refuses it, exactly like bumping into a wall.
+function Blocks.push(level, block, dx, dy)
+  local nx, ny = block.x + dx, block.y + dy
+  if not Blocks.canReceive(level, nx, ny) then return false end
+  local tile = level.map:get(nx, ny)
+  if tile == Tiles.LAVA then
+    level.map:set(nx, ny, Tiles.RUBBLE)
+    remove(level, block)
+    return true, "the block hisses into the lava and cools into rubble"
+  end
+  if tile == Tiles.CHASM then
+    level.map:set(nx, ny, Tiles.FLOOR)
+    remove(level, block)
+    return true, "the block tumbles into the chasm and fills it"
+  end
+  block.x, block.y = nx, ny
+  return true, "you shove the block"
+end
+
+-- Whether any plate linked to `gate` currently carries a block's weight.
+local function gateHeld(level, gate)
+  for _, plate in ipairs(level.plates) do
+    if plate.gateX == gate.x and plate.gateY == gate.y and level:blockAt(plate.x, plate.y) then
+      return true
+    end
+  end
+  return false
+end
+
+-- Re-evaluates every gate on the level against its own plates' current
+-- weight, flipping both its tile glyph and its `open` field the instant a
+-- plate gains or loses a block. Called after any block shove (Game:
+-- movePlayer) so a gate reacts immediately rather than waiting for a full
+-- turn tick, the same way Vaults.pull's door flip is immediate on the pull
+-- that completes it.
+function Blocks.updateGates(level)
+  for _, gate in ipairs(level.gates) do
+    local held = gateHeld(level, gate)
+    if held ~= gate.open then
+      gate.open = held
+      level.map:set(gate.x, gate.y, held and Tiles.GATE_OPEN or Tiles.GATE_CLOSED)
+    end
+  end
+end
+
+return Blocks

src/bosses.lua

@@ -0,0 +1,124 @@
+-- Named floor bosses: rare, sturdier variants of the bestiary that phase-shift
+-- once bloodied ("enrage") and always drop a superior, boss-exclusive
+-- artifact on death. A boss is otherwise a plain monster entity - it rides
+-- the same scheduler, ai.lua behaviour and abilities.lua dispatch as every
+-- other creature - so this module only adds what is genuinely new: the
+-- catalog, the enrage phase check, and the guaranteed drop.
+--
+-- A boss's second, harder-won phase - the brace-then-unleash cataclysm once
+-- it is battered all the way down to desperateAt - lives in phases.lua
+-- instead of here, since unlike enrage it spends whole turns and needs its
+-- own two-state machine; this module only supplies the catalog numbers
+-- (desperateAt, desperateDefenseBonus, novaDamage, novaRadius) it reads.
+--
+-- Builder places at most one per floor from depth 6 on, its rarity roll
+-- appended after every other placement (artifacts included) so it can never
+-- perturb an earlier system's rng sequence, exactly like artifacts.lua does
+-- for its own roll. Gating at depth 6+ also keeps bosses off every floor the
+-- fixed-maxDepth win-condition tests generate (those use maxDepth <= 3).
+
+local Entity = require("entity")
+local Artifacts = require("artifacts")
+
+local Bosses = {}
+
+Bosses.catalog = {
+  {
+    key = "warlord", glyph = "W", name = "the Orc Warlord",
+    hp = 34, attack = 7, defense = 3, speed = 100, ai = "pack",
+    minDepth = 6, xp = 40, ability = "rally",
+    enrageAt = 0.5, enrageAttack = 4, enrageSpeed = 25, enrageHeal = 6,
+    desperateAt = 0.2, desperateDefenseBonus = 5, novaDamage = 12, novaRadius = 2,
+    lootKey = "warlords_cleaver",
+  },
+  {
+    key = "lich", glyph = "L", name = "the Lich",
+    hp = 28, attack = 5, defense = 2, speed = 100, ai = "flee", range = 6,
+    minDepth = 7, xp = 45, ability = "curse",
+    enrageAt = 0.5, enrageAttack = 3, enrageSpeed = 20, enrageHeal = 8,
+    desperateAt = 0.2, desperateDefenseBonus = 4, novaDamage = 10, novaRadius = 2,
+    lootKey = "lich_phylactery",
+  },
+  {
+    key = "bonequeen", glyph = "Q", name = "the Bone Queen",
+    hp = 32, attack = 4, defense = 2, speed = 95, ai = "flee",
+    minDepth = 8, xp = 50, ability = "summon", summonSpecies = "zombie",
+    enrageAt = 0.5, enrageAttack = 3, enrageSpeed = 15, enrageHeal = 10,
+    desperateAt = 0.2, desperateDefenseBonus = 4, novaDamage = 11, novaRadius = 2,
+    lootKey = "bone_queen_carapace",
+  },
+}
+
+Bosses.byKey = {}
+for _, spec in ipairs(Bosses.catalog) do
+  Bosses.byKey[spec.key] = spec
+end
+
+-- Boss species eligible at a depth, in registry order, mirroring
+-- Monsters.forDepth so builder.lua can roll among them the same way.
+function Bosses.forDepth(depth)
+  local eligible = {}
+  for _, spec in ipairs(Bosses.catalog) do
+    if spec.minDepth <= depth then eligible[#eligible + 1] = spec end
+  end
+  return eligible
+end
+
+function Bosses.create(spec, id, x, y)
+  local entity = Entity.new({
+    id = id, x = x, y = y,
+    glyph = spec.glyph, name = spec.name, kind = "monster",
+    species = "boss_" .. spec.key, ai = spec.ai,
+    hp = spec.hp, maxHp = spec.hp,
+    attack = spec.attack, defense = spec.defense,
+    speed = spec.speed, range = spec.range or 0,
+  })
+  entity.ability = spec.ability
+  entity.summonSpecies = spec.summonSpecies
+  entity.cooldown = 0
+  entity.isBoss = true
+  entity.bossKey = spec.key
+  entity.enraged = false
+  -- Always alert: sneaking up on a named boss is not part of the design
+  -- (see stealth.lua's header for how this differs from a wild monster).
+  entity.awareness = "hunting"
+  return entity
+end
+
+-- Xp reward for felling a boss, looked up by the bossKey stamped onto it at
+-- creation. Falls back to a flat amount for a boss entity missing one, which
+-- should not happen outside of a malformed save.
+function Bosses.xpFor(entity)
+  local spec = Bosses.byKey[entity.bossKey]
+  return spec and spec.xp or 20
+end
+
+-- Checked at the start of a boss's own turn, after status ticks, hazards and
+-- regen but before its ability or plain ai runs: once bloodied past its
+-- enrageAt threshold it permanently gains attack and speed and takes a
+-- one-time heal, exactly once for the rest of the fight. Mirrors the direct
+-- stat-field mutation classes.lua uses for a permanent delta, rather than a
+-- status.lua effect, since this should never expire or be cleansed.
+function Bosses.tryEnrage(monster)
+  if not monster.isBoss or monster.enraged or not monster:isAlive() then return nil end
+  local spec = Bosses.byKey[monster.bossKey]
+  if not spec then return nil end
+  if monster.hp > monster.maxHp * spec.enrageAt then return nil end
+  monster.enraged = true
+  monster.attack = monster.attack + spec.enrageAttack
+  monster.baseAttack = monster.baseAttack + spec.enrageAttack
+  monster.speed = monster.speed + spec.enrageSpeed
+  monster.hp = math.min(monster.maxHp, monster.hp + spec.enrageHeal)
+  return string.format("%s flies into a bloodied rage", monster.name)
+end
+
+-- The guaranteed superior artifact a boss drops on death, dropped straight
+-- onto the floor at its corpse's feet by Game:awardKill rather than rolled
+-- into the ordinary loot table builder.lua scatters at level generation.
+function Bosses.lootFor(entity)
+  local spec = Bosses.byKey[entity.bossKey]
+  if not spec then return nil end
+  return Artifacts.create(spec.lootKey)
+end
+
+return Bosses

src/branches.lua

@@ -0,0 +1,83 @@
+-- Rift crossings: a rare, shimmering tear in a floor from depth six on (see
+-- builder.lua's placement, gated behind a carried rift shard) that a player
+-- can step through into a short, self-contained pocket floor - generated
+-- once from the same world seed as everything else (see Branches.build) at
+-- a deliberately harsher effective depth than the floor the rift itself sits
+-- on, so what waits behind it is always a genuine step up in danger and in
+-- reward. Unlike horde.lua's arena (a one-way trial that replaces the run's
+-- level outright), a rift crossing is round-trip: Game:enterRift remembers
+-- exactly where the player stood before stepping through, and Game:exitRift
+-- restores it to the byte, so nothing about the main dungeon left behind is
+-- ever perturbed by the detour.
+
+local Rng = require("rng")
+local Builder = require("builder")
+local Level = require("level")
+
+local Branches = {}
+
+-- How much harder a rift's own pocket floor is generated than the main-track
+-- depth its entrance sits on - fixed rather than randomised, so a rift found
+-- at a given depth always promises the same order of danger and reward.
+Branches.DEPTH_BONUS = 4
+
+-- Distinguishes a rift's own private rng stream from both the main dungeon's
+-- per-depth stream (Dungeon:levelSeed's own salt) and every other salted
+-- stream in the codebase, so discovering a rift can never perturb - or be
+-- perturbed by - any of them.
+local SALT = 0xC2B2AE3D27D4EB4F
+
+-- The deterministic seed a rift found on `depth` always builds its pocket
+-- floor from, a pure function of the world seed and the origin depth alone -
+-- never the main dungeon's own per-depth rng stream - so the exact same rift
+-- always opens onto the exact same pocket floor no matter how many times (or
+-- in what order) the run's other floors happen to be visited first.
+function Branches.seedFor(worldSeed, depth)
+  return math.tointeger(worldSeed ~ (depth * SALT)) or 0
+end
+
+-- Builds the pocket floor a rift found at `depth` opens onto: an ordinary
+-- Builder.build floor, just generated Branches.DEPTH_BONUS deeper than the
+-- rift's own origin so its monsters and loot are drawn from a rung the
+-- player has not reached yet on the main track. `options` is the run's own
+-- dungeon options (mutators, class, graves), copied rather than mutated, with
+-- maxDepth pinned one short of the pocket's own depth - short, not equal or
+-- past it, so neither of Builder.build's two maxDepth-gated passes ever fire
+-- in a pocket floor: no chasm (there is deliberately no lower pocket floor to
+-- fall into) and, far more importantly, no Amulet of Warren - a rift is a
+-- richer fight, never a shortcut past the real dungeon's own win condition.
+function Branches.build(worldSeed, depth, options)
+  local pocketDepth = depth + Branches.DEPTH_BONUS
+  local rng = Rng.new(Branches.seedFor(worldSeed, depth))
+  local pocketOptions = {}
+  for k, v in pairs(options or {}) do pocketOptions[k] = v end
+  pocketOptions.maxDepth = pocketDepth - 1
+  return Builder.build(pocketDepth, rng, pocketOptions)
+end
+
+-- Every rift's own pocket floor, serialized exactly like Dungeon:toData
+-- serializes the main track: a depth-sorted array of {depth, level} pairs, so
+-- a save taken mid-crossing (or with a rift merely discovered and never
+-- entered) restores every pocket floor already generated byte-for-byte, dead
+-- monsters and all - and stores nothing extra for a rift a run never stepped
+-- through at all.
+function Branches.levelsToData(riftLevels)
+  local depths = {}
+  for depth in pairs(riftLevels or {}) do depths[#depths + 1] = depth end
+  table.sort(depths)
+  local stored = {}
+  for _, depth in ipairs(depths) do
+    stored[#stored + 1] = { depth = depth, level = riftLevels[depth]:toData() }
+  end
+  return stored
+end
+
+function Branches.levelsFromData(stored)
+  local riftLevels = {}
+  for _, entry in ipairs(stored or {}) do
+    riftLevels[entry.depth] = Level.fromData(entry.level)
+  end
+  return riftLevels
+end
+
+return Branches

src/builder.lua

@@ -9,12 +9,51 @@ local Gen = require("gen.init")
 local Monsters = require("monsters")
 local Items = require("items")
 local Affixes = require("affixes")
+local Shop = require("shop")
+local Shrines = require("shrines")
+local Companions = require("companions")
+local Artifacts = require("artifacts")
+local Bosses = require("bosses")
+local Quests = require("quests")
+local Alchemy = require("alchemy")
+local Elites = require("elites")
+local Vaults = require("vaults")
+local Runewords = require("runewords")
+local Atmosphere = require("atmosphere")
+local Stealth = require("stealth")
+local Crafting = require("crafting")
+local Nodes = require("nodes")
+local Sets = require("sets")
+local Mimics = require("mimics")
+local Curses = require("curses")
+local Graves = require("graves")
+local Chests = require("chests")
+local Biomes = require("biomes")
+local Hazards = require("hazards")
+local Blocks = require("blocks")
+local Prefab = require("gen.prefab")
 local Level = require("level")
 
 local Builder = {}
 
 local WIDTH, HEIGHT = 60, 24
 
+-- The dungeon bottoms out here: the Amulet of Warren is guaranteed to be
+-- somewhere on this floor, and there is no way to descend past it. Tests
+-- override it via options.maxDepth to exercise a full fetch-and-return
+-- playthrough without generating nine intervening floors.
+Builder.MAX_DEPTH = 10
+
+-- The effects a random floor trap, or a trap kit rolled as loot, can carry -
+-- shared by the two draws below and exposed here so tests can assert against
+-- the authoritative list instead of a copy that would go stale the next time
+-- a new effect is appended.
+Builder.TRAP_EFFECTS = { "dart", "poison", "teleport", "confuse", "blind", "stun" }
+
+function Builder.maxDepth(options)
+  return (options and options.maxDepth) or Builder.MAX_DEPTH
+end
+
 local weaponBases = {
   { name = "dagger", power = 2 }, { name = "mace", power = 3 },
   { name = "sword", power = 4 }, { name = "battle axe", power = 5 },
@@ -23,13 +62,21 @@ local armorBases = {
   { name = "leather armor", power = 1 }, { name = "chain mail", power = 2 },
   { name = "plate armor", power = 3 },
 }
+local bowBases = {
+  { name = "short bow", power = 2, range = 5 },
+  { name = "long bow", power = 3, range = 7 },
+  { name = "crossbow", power = 4, range = 6 },
+}
 
 local NEIGHBOURS = { { 1, 0 }, { -1, 0 }, { 0, 1 }, { 0, -1 } }
 
 -- Cells reachable from (sx, sy) through walkable terrain and closed doors, and -
 -- when allowLocked is true - locked doors too. Used to guarantee the descent is
 -- never sealed behind a locked door and that keys always sit on an openable side.
-local function reachSet(map, sx, sy, allowLocked)
+-- When allowVault is also true, a sealed vault door or a closed gate (see
+-- below) counts as passable too, so the far side of an unopened vault or
+-- gate puzzle can still be found for its treasure's placement.
+local function reachSet(map, sx, sy, allowLocked, allowVault)
   local seen = { [map:index(sx, sy)] = true }
   local stack = { { sx, sy } }
   while #stack > 0 do
@@ -37,7 +84,10 @@ local function reachSet(map, sx, sy, allowLocked)
     stack[#stack] = nil
     for _, step in ipairs(NEIGHBOURS) do
       local nx, ny = cell[1] + step[1], cell[2] + step[2]
-      if map:inBounds(nx, ny) and map:isPassable(nx, ny, allowLocked) then
+      if map:inBounds(nx, ny) then
+        local passable = map:isPassable(nx, ny, allowLocked)
+          or (allowVault and (Tiles.isVaultDoor(map:get(nx, ny)) or Tiles.isGate(map:get(nx, ny))))
+        if passable then
           local idx = map:index(nx, ny)
           if not seen[idx] then
             seen[idx] = true
@@ -46,6 +96,7 @@ local function reachSet(map, sx, sy, allowLocked)
         end
       end
     end
+  end
   return seen
 end
 
@@ -81,25 +132,42 @@ end
 
 local function rollItem(rng, depth)
   local roll = rng:range(1, 100)
-  if roll <= 24 then
-    local effects = { "heal", "heal", "strength", "haste", "poison" }
+  if roll <= 22 then
+    local effects = { "heal", "heal", "strength", "haste", "poison", "clarity", "cure", "confuse", "blind", "levitate" }
     return Items.potionOf(effects[rng:range(1, #effects)])
-  elseif roll <= 40 then
+  elseif roll <= 36 then
     local effects = { "teleport", "identify", "mapping", "fireball" }
     return Items.scroll(effects[rng:range(1, #effects)])
-  elseif roll <= 60 then
+  elseif roll <= 54 then
     local base = weaponBases[rng:range(1, #weaponBases)]
     return Affixes.decorate(Items.weapon(base.name, base.power), Affixes.rollWeapon(rng))
-  elseif roll <= 76 then
+  elseif roll <= 68 then
     local base = armorBases[rng:range(1, #armorBases)]
     return Affixes.decorate(Items.armor(base.name, base.power), Affixes.rollArmor(rng))
-  elseif roll <= 86 then
+  elseif roll <= 76 then
     return Items.ring("ring of power", rng:range(0, 1), rng:range(0, 1))
+  elseif roll <= 80 then
+    local learnable = { "heal", "shield", "blink", "shock", "discord", "polymorph", "confuse", "blind", "levitate", "weaken", "cleanse" }
+    return Items.tome(learnable[rng:range(1, #learnable)])
+  elseif roll <= 84 then
+    local base = bowBases[rng:range(1, #bowBases)]
+    return Items.bow(base.name, base.power, base.range)
+  elseif roll <= 92 then
+    return Items.ammo("arrow", rng:range(4, 8))
   else
     return Items.food("ration", 400)
   end
 end
 
+-- Maps a floor item's kind to the wearable slot curses.lua knows how to
+-- afflict, so the dead-last curse pass below can find every eligible piece
+-- regardless of which earlier system placed it (a plain drop, a set piece,
+-- vault treasure, ...).
+local slotForCursableItem = {
+  [Items.WEAPON] = "weapon", [Items.ARMOR] = "armor",
+  [Items.RING] = "ring", [Items.BOW] = "bow",
+}
+
 local function chosenGenerator(depth, options)
   if options and options.generator and Gen.has(options.generator) then
     return options.generator
@@ -175,7 +243,11 @@ function Builder.build(depth, rng, options)
     end)
     if x then
       local spec = eligible[rng:range(1, #eligible)]
-      entities[#entities + 1] = Monsters.create(spec, #entities + 1, x, y, depth)
+      local monster = Monsters.create(spec, #entities + 1, x, y, depth)
+      -- A wild monster starts asleep (see stealth.lua): a plain field set,
+      -- never an rng draw, so it cannot perturb any placement roll below.
+      monster.awareness = Stealth.DORMANT
+      entities[#entities + 1] = monster
       mark(x, y)
     end
   end
@@ -189,7 +261,56 @@ function Builder.build(depth, rng, options)
     end
   end
 
-  local trapEffects = { "dart", "poison", "teleport" }
+  -- Loose gold piles and the shopkeeper (below) are both gated to depth 4+:
+  -- the shopkeeper joins Monsters.forDepth's eligible array from that depth
+  -- on, and any new rng draw here would otherwise reshuffle the trap/light/
+  -- amulet placement the fixed-maxDepth win-condition tests rely on for the
+  -- shallow floors they actually exercise.
+  if depth >= 4 then
+    local goldCount = rng:range(1, 3)
+    for _ = 1, goldCount do
+      local x, y = pickFree(reachable, rng, freeFloor)
+      if x then
+        floorItems[#floorItems + 1] = { x = x, y = y, item = Items.gold(rng:range(8, 20) + depth * 4) }
+        mark(x, y)
+      end
+    end
+  end
+
+  -- A shopkeeper occasionally sets up on a floor, guarding a handful of
+  -- priced wares. Gold to spend there comes from the loose piles above.
+  if depth >= 4 and rng:chance(1, 3) then
+    local sx, sy = pickFree(reachable, rng, freeFloor)
+    if sx then
+      local keeper = Monsters.create(Monsters.byKey.shopkeeper, #entities + 1, sx, sy, depth)
+      entities[#entities + 1] = keeper
+      mark(sx, sy)
+      for _, item in ipairs(Shop.stock(rng)) do
+        local x, y = pickFree(reachable, rng, freeFloor)
+        if x then
+          floorItems[#floorItems + 1] = {
+            x = x, y = y, item = item, price = Shop.priceOf(item), shopId = keeper.id,
+          }
+          mark(x, y)
+        end
+      end
+    end
+  end
+
+  -- Shrines join the shop above at depth 4+, for the same reason: an earlier
+  -- rng draw would reshuffle the trap/light/amulet placement the fixed-
+  -- maxDepth win-condition tests rely on for the shallow floors they exercise.
+  local shrines = {}
+  if depth >= 4 and rng:chance(1, 4) then
+    local x, y = pickFree(reachable, rng, freeFloor)
+    if x then
+      local kind = Shrines.order[rng:range(1, #Shrines.order)]
+      shrines[#shrines + 1] = { x = x, y = y, kind = kind, uses = 0 }
+      mark(x, y)
+    end
+  end
+
+  local trapEffects = Builder.TRAP_EFFECTS
   local trapCount = rng:range(1, 3) + depth // 3
   for _ = 1, trapCount do
     local x, y = pickFree(reachable, rng, freeFloor)
@@ -199,6 +320,14 @@ function Builder.build(depth, rng, options)
     end
   end
 
+  if depth == Builder.maxDepth(options) then
+    local x, y = pickFree(reachable, rng, freeFloor)
+    if x then
+      floorItems[#floorItems + 1] = { x = x, y = y, item = Items.amulet() }
+      mark(x, y)
+    end
+  end
+
   local dark = depth >= 3
   if dark then
     for _ = 1, rng:range(1, 3) do
@@ -207,14 +336,664 @@ function Builder.build(depth, rng, options)
     end
   end
 
+  -- A companion's bonding charm is the rarest of the depth-gated placements
+  -- and, unlike the others, drawn last so it can never perturb the rng
+  -- sequence any earlier system (traps, shrines, the shop, the amulet) relies
+  -- on for its own placement.
+  if depth >= 3 and rng:chance(1, 5) then
+    local x, y = pickFree(reachable, rng, freeFloor)
+    if x then
+      local key = Companions.order[rng:range(1, #Companions.order)]
+      floorItems[#floorItems + 1] = { x = x, y = y, item = Items.charm(key) }
+      mark(x, y)
+    end
+  end
+
+  -- Rarer still, and drawn last of all for the same rng-ordering reason as
+  -- the charm above: a named artifact with a fixed, always-on mechanic.
+  if depth >= 5 and rng:chance(1, 6) then
+    local x, y = pickFree(reachable, rng, freeFloor)
+    if x then
+      local key = Artifacts.order[rng:range(1, #Artifacts.order)]
+      floorItems[#floorItems + 1] = { x = x, y = y, item = Artifacts.create(key) }
+      mark(x, y)
+    end
+  end
+
+  -- A trap kit lets the player plant one of these same effects
+  -- themselves (see Game:useItem's KIT branch and Game:checkTrapFor, which
+  -- springs a planted trap on a monster exactly as a builder-placed one
+  -- springs on the player). Drawn last of all so it can never perturb any
+  -- earlier system's rng sequence, the charm and artifact included.
+  if depth >= 2 and rng:chance(1, 4) then
+    local x, y = pickFree(reachable, rng, freeFloor)
+    if x then
+      floorItems[#floorItems + 1] = { x = x, y = y, item = Items.kit(trapEffects[rng:range(1, #trapEffects)]) }
+      mark(x, y)
+    end
+  end
+
+  -- A named boss rarer still guards the deepest floors, drawn dead last of
+  -- all for the same rng-ordering reason as the kit above: it can never
+  -- perturb any earlier system's placement, artifacts included.
+  if depth >= 6 and rng:chance(1, 5) then
+    local eligible = Bosses.forDepth(depth)
+    if #eligible > 0 then
+      local x, y = pickFree(reachable, rng, freeFloor)
+      if x then
+        local spec = eligible[rng:range(1, #eligible)]
+        entities[#entities + 1] = Bosses.create(spec, #entities + 1, x, y)
+        mark(x, y)
+      end
+    end
+  end
+
+  -- A bounty board rarer than a trap kit but commoner than an artifact,
+  -- offering a single fixed pact the moment the player steps onto it (see
+  -- Game:tryAcceptQuest). Drawn dead last of all for the same rng-ordering
+  -- reason as the boss above: it can never perturb any earlier system's
+  -- placement, the boss included.
+  local questBoards = {}
+  if depth >= 2 and rng:chance(1, 4) then
+    local x, y = pickFree(reachable, rng, freeFloor)
+    if x then
+      questBoards[#questBoards + 1] = {
+        x = x, y = y, claimed = false,
+        quest = Quests.generate(rng, depth, Builder.maxDepth(options)),
+      }
+    end
+  end
+
+  -- Herbs dot every floor from the first, foraging material rather than a
+  -- depth-gated reward. Drawn dead last of all, after the quest board, so
+  -- they can never perturb any earlier system's rng sequence.
+  local herbCount = rng:range(2, 4)
+  for _ = 1, herbCount do
+    local x, y = pickFree(reachable, rng, freeFloor)
+    if x then
+      local key = Alchemy.order[rng:range(1, #Alchemy.order)]
+      floorItems[#floorItems + 1] = { x = x, y = y, item = Alchemy.herb(key) }
+      mark(x, y)
+    end
+  end
+
+  -- A cauldron to brew those herbs at, rarer than the herbs themselves and
+  -- gated to depth 2+ so the entrance floor is foraging-only. Drawn last of
+  -- all for the same rng-ordering reason as the herbs above.
+  local cauldrons = {}
+  if depth >= 2 and rng:chance(1, 4) then
+    local x, y = pickFree(reachable, rng, freeFloor)
+    if x then
+      cauldrons[#cauldrons + 1] = { x = x, y = y }
+      mark(x, y)
+    end
+  end
+
+  -- Volatile terrain rarer than a cauldron, gated to depth 4+ so the entry
+  -- floors are always safe: a lava pool of two to four adjoining cells that
+  -- burns anyone standing on it (see Game:checkTerrainFor), a single chasm
+  -- pit that drops the player to the floor below and swallows a monster
+  -- whole (capped to floors that still have one to fall onto), and a patch
+  -- of ice that sends a traveller sliding. Drawn dead last of all for the
+  -- same rng-ordering reason as the cauldron above.
+  if depth >= 4 and rng:chance(1, 4) then
+    local x, y = pickFree(reachable, rng, freeFloor)
+    if x then
+      map:set(x, y, Tiles.LAVA)
+      mark(x, y)
+      for _ = 1, rng:range(1, 3) do
+        local dir = NEIGHBOURS[rng:range(1, #NEIGHBOURS)]
+        local nx, ny = x + dir[1], y + dir[2]
+        if freeFloor(nx, ny) then
+          map:set(nx, ny, Tiles.LAVA)
+          mark(nx, ny)
+        end
+      end
+    end
+  end
+
+  if depth >= 4 and depth < Builder.maxDepth(options) and rng:chance(1, 5) then
+    local x, y = pickFree(reachable, rng, freeFloor)
+    if x then
+      map:set(x, y, Tiles.CHASM)
+      mark(x, y)
+    end
+  end
+
+  if depth >= 4 and rng:chance(1, 4) then
+    local x, y = pickFree(reachable, rng, freeFloor)
+    if x then
+      map:set(x, y, Tiles.ICE)
+      mark(x, y)
+      for _ = 1, rng:range(1, 4) do
+        local dir = NEIGHBOURS[rng:range(1, #NEIGHBOURS)]
+        local nx, ny = x + dir[1], y + dir[2]
+        if freeFloor(nx, ny) then
+          map:set(nx, ny, Tiles.ICE)
+          mark(nx, ny)
+        end
+      end
+    end
+  end
+
+  -- Elite promotion rolls last of all, dead after the ice above: it only
+  -- edits stats already-placed entities carry, never a position, so it
+  -- cannot desync reachability - but rng-ordering discipline still applies,
+  -- since it draws from the same stream every earlier placement in this
+  -- floor already relied on.
+  for _, entity in ipairs(entities) do
+    Elites.maybePromote(rng, entity, depth)
+  end
+
+  -- A vault seals a treasure behind a lever puzzle instead of a key: a door
+  -- set on an unused doorway pinch point that only swings open once every
+  -- lever scattered on the side already reachable without it has been
+  -- pulled (see vaults.lua). Rarer than a boss and drawn dead last of all so
+  -- it can never perturb any earlier system's rng sequence, the boss and
+  -- quest board included. Falls back to an ordinary closed door whenever the
+  -- floor's geometry cannot host a genuine puzzle (no free doorway, no room
+  -- for its levers, or no cell the door actually gates), so a vault never
+  -- seals content behind an unsolvable or pointless door.
+  local vaultLevers, vaultDoors = {}, {}
+  if depth >= 5 and rng:chance(1, 6) then
+    local doorCandidates = doorwayCandidates(map)
+    for i = #doorCandidates, 1, -1 do
+      if taken(doorCandidates[i].x, doorCandidates[i].y) then
+        table.remove(doorCandidates, i)
+      end
+    end
+    if #doorCandidates > 0 then
+      local cell = doorCandidates[rng:range(1, #doorCandidates)]
+      map:set(cell.x, cell.y, Tiles.VAULT_DOOR)
+      mark(cell.x, cell.y)
+      local vaultId = "vault" .. depth
+      local openSide = reachSet(map, upX, upY, false, false)
+      local leverCount = rng:range(2, 3)
+      for _ = 1, leverCount do
+        local x, y = pickFree(reachable, rng, function(cx, cy)
+          return freeFloor(cx, cy) and openSide[map:index(cx, cy)] == true
+        end)
+        if x then
+          map:set(x, y, Tiles.LEVER)
+          vaultLevers[#vaultLevers + 1] = { x = x, y = y, id = vaultId, pulled = false }
+          mark(x, y)
+        end
+      end
+      local farSide = reachSet(map, upX, upY, false, true)
+      local tx, ty
+      if #vaultLevers > 0 then
+        tx, ty = pickFree(reachable, rng, function(cx, cy)
+          return freeFloor(cx, cy) and farSide[map:index(cx, cy)] == true
+            and openSide[map:index(cx, cy)] ~= true
+        end)
+      end
+      if tx then
+        vaultDoors[#vaultDoors + 1] = { x = cell.x, y = cell.y, id = vaultId, opened = false }
+        floorItems[#floorItems + 1] = { x = tx, y = ty, item = Vaults.treasure(rng, depth) }
+        mark(tx, ty)
+      else
+        -- No lever site or no cell the door actually gates: back out to a
+        -- plain closed door so the puzzle is never unsolvable or hollow, and
+        -- free the lever tiles this attempt already claimed.
+        map:set(cell.x, cell.y, Tiles.DOOR_CLOSED)
+        for _, lever in ipairs(vaultLevers) do
+          map:set(lever.x, lever.y, Tiles.FLOOR)
+        end
+        vaultLevers = {}
+      end
+    end
+  end
+
+  -- Rune stones dot the dungeon from depth three on, rarer than a herb but
+  -- commoner than a trap kit: raw components for runewords.lua's
+  -- socket-and-match combo system, found rather than crafted so a build is
+  -- bounded by what the floor actually offers. Drawn dead last of all,
+  -- after the vault above, so it can never perturb any earlier system's
+  -- rng sequence.
+  if depth >= 3 and rng:chance(1, 2) then
+    local x, y = pickFree(reachable, rng, freeFloor)
+    if x then
+      local key = Runewords.RUNES[rng:range(1, #Runewords.RUNES)]
+      floorItems[#floorItems + 1] = { x = x, y = y, item = Runewords.rune(key) }
+      mark(x, y)
+    end
+  end
+
+  -- A floor-wide weather condition, drawn dead last of all so it can never
+  -- perturb any earlier system's rng sequence: an infested reading retroactively
+  -- bumps every monster already placed on this floor (exactly like Elites.
+  -- maybePromote's own retroactive stat edit above), since only a stat and
+  -- never a position is at stake.
+  local weather
+  if depth >= 2 and rng:chance(1, 3) then
+    weather = Atmosphere.order[rng:range(1, #Atmosphere.order)]
+    local attackBonus = Atmosphere.monsterAttackBonus(weather)
+    if attackBonus > 0 then
+      for _, entity in ipairs(entities) do
+        entity.attack = entity.attack + attackBonus
+        entity.baseAttack = entity.baseAttack + attackBonus
+      end
+    end
+  end
+
+  -- Ore veins and gem seams dot the dungeon from the second floor on, dead
+  -- last of all so they can never perturb any earlier system's rng sequence:
+  -- unlike the herbs above, a single visit does not spend a node outright -
+  -- it holds a few charges and slowly reopens (see nodes.lua) - so a floor
+  -- already cleared of monsters still rewards a return trip.
+  local nodes = {}
+  if depth >= 2 then
+    local veinCount = rng:range(1, 2)
+    for _ = 1, veinCount do
+      local x, y = pickFree(reachable, rng, freeFloor)
+      if x then
+        local kind = rng:chance(1, 2) and Nodes.ORE or Nodes.GEM
+        local element = kind == Nodes.GEM and Crafting.elements[rng:range(1, #Crafting.elements)] or nil
+        local node = Nodes.new(kind, element)
+        node.x, node.y = x, y
+        nodes[#nodes + 1] = node
+        mark(x, y)
+      end
+    end
+  end
+
+  -- A single item-set piece dots the dungeon from depth three on, rarer
+  -- than a rune but commoner than an artifact: unlike an artifact's fixed
+  -- always-on mechanic, a set piece is inert alone and only pays off once
+  -- its match turns up too (see sets.lua). Drawn dead last of all, after
+  -- the nodes above, so it can never perturb any earlier system's rng
+  -- sequence.
+  if depth >= 3 and rng:chance(1, 5) then
+    local x, y = pickFree(reachable, rng, freeFloor)
+    if x then
+      local entry = Sets.order[rng:range(1, #Sets.order)]
+      floorItems[#floorItems + 1] = { x = x, y = y, item = Sets.create(entry.set, entry.slot) }
+      mark(x, y)
+    end
+  end
+
+  -- A single mimic disguises itself as loot from depth two on, rarer than
+  -- a trap kit: unlike every item placed above, it is inert to look at and
+  -- only bites once the player actually reaches for it (see mimics.lua).
+  -- Drawn dead last of all, after the set piece above, so it can never
+  -- perturb any earlier system's rng sequence.
+  if depth >= 2 and rng:chance(1, 6) then
+    local x, y = pickFree(reachable, rng, freeFloor)
+    if x then
+      floorItems[#floorItems + 1] = { x = x, y = y, item = Mimics.floorItem(rng) }
+      mark(x, y)
+    end
+  end
+
+  -- A scroll of remove curse turns up rarer than a mimic, the one dedicated
+  -- remedy for the curse pass below that a run can actually find rather than
+  -- having to gamble on a shrine of fortune. Drawn dead last of all, after
+  -- the mimic above, so it can never perturb any earlier system's rng
+  -- sequence.
+  if depth >= 2 and rng:chance(1, 8) then
+    local x, y = pickFree(reachable, rng, freeFloor)
+    if x then
+      floorItems[#floorItems + 1] = { x = x, y = y, item = Items.scroll("removecurse") }
+      mark(x, y)
+    end
+  end
+
+  -- Curses.lua's dark mirror of affixes.lua rolls dead last of all, after
+  -- every item above has already been placed: it only edits the stats of
+  -- weapons, armor, rings and bows already sitting in floorItems, never a
+  -- position, so it cannot desync reachability - but rng-ordering discipline
+  -- still applies, since it draws from the same stream every earlier
+  -- placement in this floor already relied on. Skips anything that already
+  -- landed a beneficial affix or names its own set/artifact, so a single
+  -- drop is never simultaneously a blessing and a curse.
+  for _, ground in ipairs(floorItems) do
+    local slot = slotForCursableItem[ground.item.kind]
+    if slot and not ground.price and not ground.item.affix and not ground.item.set and not ground.item.artifact then
+      local curse = Curses.roll(rng, slot)
+      if curse then Curses.afflict(ground.item, curse) end
+    end
+  end
+
+  -- A miner's pick turns up rarer than the remove-curse scroll above, the
+  -- one way a run can find its own way into a rock burrower's tunnel or dig
+  -- a shortcut through a dead-end wall (see digging.lua). Drawn dead last
+  -- of all, after the curse pass above, so it can never perturb any
+  -- earlier system's rng sequence.
+  if depth >= 2 and rng:chance(1, 10) then
+    local x, y = pickFree(reachable, rng, freeFloor)
+    if x then
+      floorItems[#floorItems + 1] = { x = x, y = y, item = Items.pick() }
+      mark(x, y)
+    end
+  end
+
+  -- A lockpick turns up commoner than the miner's pick above, drawn dead
+  -- last of all so it can never perturb any earlier system's rng sequence:
+  -- the one way a run can gamble past a locked chest's lock without ever
+  -- finding its key (see chests.lua's Chests.pick).
+  if rng:chance(1, 4) then
+    local x, y = pickFree(reachable, rng, freeFloor)
+    if x then
+      floorItems[#floorItems + 1] = { x = x, y = y, item = Items.lockpick() }
+      mark(x, y)
+    end
+  end
+
+  -- A single lootable chest dots the dungeon from the first floor on, rarer
+  -- than a lockpick, drawn dead last of all so it can never perturb any
+  -- earlier system's rng sequence: a locked one may also be trapped (see
+  -- Chests.new), so a run either finds a key, gambles a lockpick, or leaves
+  -- it be.
+  local chests = {}
+  if rng:chance(1, 3) then
+    local x, y = pickFree(reachable, rng, freeFloor)
+    if x then
+      local chest = Chests.new(rng, depth)
+      chest.x, chest.y = x, y
+      chests[#chests + 1] = chest
+      mark(x, y)
+    end
+  end
+
+  -- A secret door hides a single alcove of bonus loot behind an otherwise
+  -- ordinary stretch of wall, found only by lingering beside it long enough
+  -- (see secrets.lua's passive sweep). Drawn dead last of all before the
+  -- grave below - which must stay the true last word, since it is the one
+  -- block whose own rng draw count depends on what the caller passed in
+  -- (see its own comment) - so this can never perturb any earlier system's
+  -- rng sequence either: picks an already-reachable floor cell and a
+  -- direction whose neighbour and whose cell two further along are both
+  -- still untouched solid rock, then carves that far cell into a one-tile
+  -- room holding a single roll of loot. The door itself stays a plain wall
+  -- tile until secrets.lua's sweep discovers it - this list only remembers
+  -- where to look. Skipped outright whenever 40 random reachable cells in a
+  -- row turn up no such spot, so a cramped floor's own geometry never
+  -- forces the roll to place nothing.
+  local secretDoors = {}
+  if depth >= 2 and rng:chance(1, 4) then
+    for _ = 1, 40 do
+      local cell = reachable[rng:range(1, #reachable)]
+      local dir = NEIGHBOURS[rng:range(1, #NEIGHBOURS)]
+      local doorX, doorY = cell.x + dir[1], cell.y + dir[2]
+      local roomX, roomY = cell.x + dir[1] * 2, cell.y + dir[2] * 2
+      if roomX >= 2 and roomY >= 2 and roomX <= map.width - 1 and roomY <= map.height - 1
+        and map:get(doorX, doorY) == Tiles.WALL and map:get(roomX, roomY) == Tiles.WALL then
+        -- The room's only walkable neighbour may be the door itself: if any
+        -- of its other three sides already happens to border open floor
+        -- somewhere else in the layout, that side would let the player
+        -- wander straight into the alcove without ever finding the door,
+        -- so a candidate site with any such back way in is rejected outright.
+        local isolated = true
+        for _, side in ipairs(NEIGHBOURS) do
+          local ax, ay = roomX + side[1], roomY + side[2]
+          if not (ax == doorX and ay == doorY) and map:isWalkable(ax, ay) then
+            isolated = false
+            break
+          end
+        end
+        if isolated then
+          map:set(roomX, roomY, Tiles.FLOOR)
+          secretDoors[#secretDoors + 1] = { x = doorX, y = doorY, discovered = false }
+          floorItems[#floorItems + 1] = { x = roomX, y = roomY, item = rollItem(rng, depth) }
+          break
+        end
+      end
+    end
+  end
+
+  -- A biome reinforcement and hazard bloom, drawn dead last of all before
+  -- the grave below - which must stay the true last word, since it is the
+  -- one block whose own rng draw count depends on what the caller passed in
+  -- (see its own comment) - so this can never perturb any earlier system's
+  -- rng sequence either: see biomes.lua for why a floor's biome is a fixed
+  -- function of depth rather than another dice roll like weather. The
+  -- reinforcement draws only from natives of the eligible roster already
+  -- computed above, so it can never plant a monster too deep for its own
+  -- minDepth, and starts dormant exactly like every other wild monster
+  -- placed above (see Stealth.DORMANT); the bloom seeds level.hazards the
+  -- same way a fire spell or a trap would mid-game, just already
+  -- smouldering the moment the floor is first entered.
+  local biome = Biomes.forDepth(depth)
+  local natives = Biomes.nativesAmong(biome, eligible)
+  if #natives > 0 and rng:chance(1, 3) then
+    local x, y = pickFree(reachable, rng, freeFloor)
+    if x then
+      local spec = natives[rng:range(1, #natives)]
+      local monster = Monsters.create(spec, #entities + 1, x, y, depth)
+      monster.awareness = Stealth.DORMANT
+      entities[#entities + 1] = monster
+      mark(x, y)
+    end
+  end
+
+  local hazards = {}
+  if rng:chance(1, 4) then
+    local x, y = pickFree(reachable, rng, freeFloor)
+    if x then
+      hazards[#hazards + 1] = { x = x, y = y, kind = biome.hazardKind, duration = 4, potency = 2 }
+    end
+  end
+
+  -- A pressure gate seals a second stash behind a shove puzzle instead of a
+  -- lever pull: a gate set on an unused doorway pinch point that only stays
+  -- open while a block's weight rests on its linked plate (see blocks.lua),
+  -- rather than a lever's one-way, permanently-spent pull. The block always
+  -- sits exactly two cells from its plate along a single cardinal direction,
+  -- with the cell behind the block itself also free, so a single shove from
+  -- that approach cell always lands it on the plate - the puzzle is never a
+  -- multi-step arrangement a floor's own cramped geometry might make
+  -- unsolvable. Also verifies, after sealing the gate shut, that the stairs
+  -- down are still reachable without ever crossing it - exactly the same
+  -- guarantee the locked-door pass above gives a key - so a gate can only
+  -- ever seal optional treasure, never the one path through the floor.
+  -- Falls back to an ordinary closed door whenever the floor's geometry
+  -- cannot host a genuine puzzle (no free doorway, no straight three-cell
+  -- run for the plate/block/approach, or the gate would seal the only route
+  -- to the stairs), so a gate never seals content behind an unsolvable or
+  -- pointless door. Drawn dead last of all before the grave below - which
+  -- must stay the true last word (see its own comment) - so this can never
+  -- perturb any earlier system's rng sequence either.
+  local blocks, plates, gates = {}, {}, {}
+  if depth >= 3 and rng:chance(1, 5) then
+    local doorCandidates = doorwayCandidates(map)
+    for i = #doorCandidates, 1, -1 do
+      if taken(doorCandidates[i].x, doorCandidates[i].y) then
+        table.remove(doorCandidates, i)
+      end
+    end
+    if #doorCandidates > 0 then
+      local cell = doorCandidates[rng:range(1, #doorCandidates)]
+      map:set(cell.x, cell.y, Tiles.GATE_CLOSED)
+      mark(cell.x, cell.y)
+      local sealsTheOnlyRoute = not reachSet(map, upX, upY, false)[map:index(downX, downY)]
+      local openSide = reachSet(map, upX, upY, false, false)
+      local function onOpenSide(cx, cy)
+        return freeFloor(cx, cy) and openSide[map:index(cx, cy)] == true
+      end
+      local px, py = pickFree(reachable, rng, onOpenSide)
+      local siteDirs = {}
+      if px then
+        for _, dir in ipairs(NEIGHBOURS) do
+          local bx, by = px - dir[1], py - dir[2]
+          local ax, ay = bx - dir[1], by - dir[2]
+          if onOpenSide(bx, by) and onOpenSide(ax, ay) then
+            siteDirs[#siteDirs + 1] = { bx = bx, by = by }
+          end
+        end
+      end
+      local tx, ty
+      if not sealsTheOnlyRoute and #siteDirs > 0 then
+        local farSide = reachSet(map, upX, upY, false, true)
+        tx, ty = pickFree(reachable, rng, function(cx, cy)
+          return freeFloor(cx, cy) and farSide[map:index(cx, cy)] == true
+            and openSide[map:index(cx, cy)] ~= true
+        end)
+      end
+      if tx then
+        local site = siteDirs[rng:range(1, #siteDirs)]
+        plates[#plates + 1] = { x = px, y = py, gateX = cell.x, gateY = cell.y }
+        blocks[#blocks + 1] = { x = site.bx, y = site.by }
+        gates[#gates + 1] = { x = cell.x, y = cell.y, open = false }
+        mark(px, py)
+        mark(site.bx, site.by)
+        floorItems[#floorItems + 1] = { x = tx, y = ty, item = Blocks.treasure(rng, depth) }
+        mark(tx, ty)
+      else
+        map:set(cell.x, cell.y, Tiles.DOOR_CLOSED)
+      end
+    end
+  end
+
+  -- A hand-authored prefab vault dots the deep dungeon from depth three on,
+  -- sealed behind solid rock rather than gated by a key or a lever: the one
+  -- way in is digging.lua's pick (or a burrower's own claws), swung from
+  -- whichever reachable cell happens to border its outer wall. Anchored only
+  -- over untouched rock - every cell of its footprint still the generator's
+  -- own default fill - so it can never overwrite a corridor or room this
+  -- floor's own generator already carved, and only accepted once at least
+  -- one of its wall cells actually borders the reachable area, so a vault
+  -- can never end up sealed unreachably deep inside solid rock no digger
+  -- could ever find. Its monster and loot markers (see gen/prefab.lua) draw
+  -- from the same eligible roster and item tables every earlier pass in this
+  -- floor already used. Drawn dead last of all before the grave below -
+  -- which must stay the true last word (see its own comment) - so this can
+  -- never perturb any earlier system's rng sequence either.
+  local prefabVaults = {}
+  if depth >= 3 and rng:chance(1, 5) then
+    local vault = Prefab.vaults[rng:range(1, #Prefab.vaults)]
+    local w, h = Prefab.size(vault)
+    local vaultReach = reachSet(map, upX, upY, false)
+    for _ = 1, 40 do
+      local ox = rng:range(2, map.width - w)
+      local oy = rng:range(2, map.height - h)
+      if Prefab.fits(map, vault, ox, oy) then
+        local untouched = true
+        for y = oy, oy + h - 1 do
+          for x = ox, ox + w - 1 do
+            if map:get(x, y) ~= Tiles.WALL then untouched = false end
+          end
+        end
+        local bordersReachable = false
+        for y = oy - 1, oy + h do
+          for x = ox - 1, ox + w do
+            local onPerimeter = x < ox or x > ox + w - 1 or y < oy or y > oy + h - 1
+            if onPerimeter and map:inBounds(x, y) and vaultReach[map:index(x, y)] then
+              bordersReachable = true
+            end
+          end
+        end
+        if untouched and bordersReachable then
+          local stamp = Prefab.stamp(map, vault, ox, oy)
+          for _, spot in ipairs(stamp.treasure) do
+            floorItems[#floorItems + 1] = { x = spot.x, y = spot.y, item = Vaults.treasure(rng, depth) }
+            mark(spot.x, spot.y)
+          end
+          for _, spot in ipairs(stamp.loot) do
+            floorItems[#floorItems + 1] = { x = spot.x, y = spot.y, item = rollItem(rng, depth) }
+            mark(spot.x, spot.y)
+          end
+          for _, spot in ipairs(stamp.monsters) do
+            local spec = eligible[rng:range(1, #eligible)]
+            local monster = Monsters.create(spec, #entities + 1, spot.x, spot.y, depth)
+            monster.awareness = Stealth.DORMANT
+            entities[#entities + 1] = monster
+            mark(spot.x, spot.y)
+          end
+          prefabVaults[#prefabVaults + 1] = { name = stamp.name, x = ox, y = oy, w = w, h = h }
+          break
+        end
+      end
+    end
+  end
+
+  -- A net turns up from depth five on, rarer than a miner's pick, drawn dead
+  -- last of all - after even the prefab vault pass above - so it can never
+  -- perturb any earlier system's rng sequence: the one way a run carries the
+  -- means to subdue a battered monster alive instead of finishing it off
+  -- (see captives.lua), rather than a strictly worse copy of an ordinary
+  -- weapon. Gated this deep so it can never turn up in the fixed shallow
+  -- worlds the win-condition tests build with a low --maxDepth.
+  if depth >= 5 and rng:chance(1, 6) then
+    local x, y = pickFree(reachable, rng, freeFloor)
+    if x then
+      floorItems[#floorItems + 1] = { x = x, y = y, item = Items.net() }
+      mark(x, y)
+    end
+  end
+
+  -- A rift shard turns up from depth four on, rarer than a net, drawn dead
+  -- last of all - after the net above - so it can never perturb any earlier
+  -- system's rng sequence: fuel for the one crossing a rift (below) actually
+  -- costs (see branches.lua), found a couple of floors ahead of where a rift
+  -- can itself first appear so a run always has a real chance to be carrying
+  -- one the day it matters.
+  if depth >= 4 and rng:chance(1, 6) then
+    local x, y = pickFree(reachable, rng, freeFloor)
+    if x then
+      floorItems[#floorItems + 1] = { x = x, y = y, item = Items.riftstone() }
+      mark(x, y)
+    end
+  end
+
+  -- A rift tears open rarer still, only from depth six on, drawn dead last
+  -- of all - after the shard above - so it can never perturb any earlier
+  -- system's rng sequence: a shimmering, unstable seam in the floor a
+  -- carried rift shard alone can stabilize into a crossing onto a short,
+  -- harsher pocket floor (see branches.lua and Game:enterRift). Plain
+  -- position-keyed level data exactly like a shrine or a node, never a tile
+  -- of its own, so it needs no new entry in tiles.lua.
+  local rifts = {}
+  if depth >= 6 and rng:chance(1, 8) then
+    local x, y = pickFree(reachable, rng, freeFloor)
+    if x then
+      rifts[#rifts + 1] = { x = x, y = y }
+      mark(x, y)
+    end
+  end
+
+  -- A previous run's grave turns up rarer than a pick, dead last of all -
+  -- after the lockpick, chest, secret door, biome, gate and net pass above -
+  -- so it can never perturb any earlier system's rng sequence: cross-run
+  -- bones (see graves.lua), rolled only when the caller actually supplies
+  -- any - a run without --meta, or a fresh meta with no recorded deaths
+  -- yet, makes no extra rng draw here at all, so its floors stay
+  -- byte-identical to a build with no graves system in play.
+  if options and options.graves and #options.graves > 0 then
+    local eligibleGraves = Graves.eligibleFor(options.graves, depth)
+    if #eligibleGraves > 0 and rng:chance(1, 5) then
+      local x, y = pickFree(reachable, rng, freeFloor)
+      if x then
+        local grave = eligibleGraves[rng:range(1, #eligibleGraves)]
+        floorItems[#floorItems + 1] = { x = x, y = y, item = Graves.floorItem(grave) }
+        mark(x, y)
+      end
+    end
+  end
+
   return Level.new({
     depth = depth,
     generator = generator,
+    weather = weather,
+    biome = biome.key,
     map = map,
     entities = entities,
     floorItems = floorItems,
     traps = traps,
     lights = lights,
+    hazards = hazards,
+    shrines = shrines,
+    questBoards = questBoards,
+    cauldrons = cauldrons,
+    nodes = nodes,
+    chests = chests,
+    vaultLevers = vaultLevers,
+    vaultDoors = vaultDoors,
+    secretDoors = secretDoors,
+    blocks = blocks,
+    plates = plates,
+    gates = gates,
+    prefabVaults = prefabVaults,
+    rifts = rifts,
     dark = dark,
     explored = {},
     upX = upX, upY = upY,

src/captives.lua

@@ -0,0 +1,160 @@
+-- Net-and-ransom: throwing a spare net at a wild monster too battered to
+-- keep fighting subdues it alive instead of finishing it off with a killing
+-- blow. A captured monster never runs through Game:awardKill at all - no
+-- xp, no essence, no quest or compendium credit, no faction kill penalty
+-- (see factions.lua's registerKill) and no corpse (corpses.lua) - it is
+-- simply dropped from level.entities the instant its hp hits zero here, and
+-- reborn as a captive: plain data on level.captives, exactly like a chest
+-- or a corpse, so it serializes with no special save-format handling.
+--
+-- A held captive can then be spent exactly one of three ways, each removing
+-- it from level.captives for good: ransomed back to its own kind for
+-- nothing but goodwill (Captives.ransom), sold off for gold at that same
+-- goodwill's expense (Captives.sell), or interrogated for whatever it knows
+-- instead of what it is worth (Captives.interrogate, which cashes in
+-- secrets.lua's own passive search early). None of the three is strictly
+-- better than the others - ransoming is the one move that can pull a
+-- tribal faction back from the brink of open hostility (see factions.lua's
+-- isWary), selling is the only one that pays gold, and interrogating is the
+-- only one that answers to the floor's own layout rather than to gold or
+-- reputation at all.
+--
+-- Capture is a gamble, not a guarantee: even a target already weak enough
+-- to try for can still thrash free, and the net itself is spent from the
+-- inventory either way, the same one-shot risk a lockpick's own gamble
+-- takes against a locked chest. A net never works at all on anything
+-- already spoken for by another escalation or special-case system - a
+-- boss, a mimic, a grave shade, a nemesis, or the shopkeeper (ai "vend",
+-- effectively unkillable loot rather than wild game to begin with).
+
+local Los = require("los")
+local Items = require("items")
+local Monsters = require("monsters")
+local Elites = require("elites")
+local Factions = require("factions")
+local Secrets = require("secrets")
+
+local Captives = {}
+
+Captives.RANGE = 4
+
+-- A target must be battered down to this fraction of its own max hp or
+-- lower before a net is even worth trying - full-health prey just shrugs a
+-- net off before Captives.resolve ever rolls the catch itself.
+Captives.HP_FRACTION_NUMERATOR = 3
+Captives.HP_FRACTION_DENOMINATOR = 10
+
+Captives.CATCH_NUMERATOR = 1
+Captives.CATCH_DENOMINATOR = 2
+
+Captives.RANSOM_REP_GAIN = 12
+Captives.SELL_REP_LOSS = 8
+Captives.INTERROGATE_ESSENCE_DIVISOR = 2
+
+-- Whether `target` is even worth throwing a net at: alive, an ordinary wild
+-- hostile (not a boss, mimic, grave shade or nemesis, and not the vending
+-- shopkeeper), and hurt down to HP_FRACTION_NUMERATOR/DENOMINATOR of its own
+-- max hp or less.
+function Captives.eligible(target)
+  return target ~= nil
+    and target:isAlive()
+    and target.kind == "monster"
+    and target.ai ~= "vend"
+    and not target.isBoss
+    and not target.mimic
+    and not target.grave
+    and not target.nemesis
+    and target.hp * Captives.HP_FRACTION_DENOMINATOR <= target.maxHp * Captives.HP_FRACTION_NUMERATOR
+end
+
+-- Same shape as throwing.lua's Throwing.canReach: a net flies no further
+-- than RANGE and needs an unbroken line of sight, same as any thrown weapon.
+function Captives.canReach(map, x1, y1, x2, y2)
+  local dist = math.max(math.abs(x1 - x2), math.abs(y1 - y2))
+  return dist <= Captives.RANGE and Los.clear(map, x1, y1, x2, y2)
+end
+
+-- Gold/essence baseline shared by every resolution below: the same xp a
+-- kill would have paid, elite-boosted the same way Game:awardKill's own xp
+-- is (see elites.lua), so a netted champion is worth visibly more than a
+-- netted rank-and-file of the same species.
+function Captives.valueOf(target)
+  local xp = Monsters.xpFor(target)
+  return xp + Elites.xpBonus(target, xp)
+end
+
+-- Resolves a net thrown from (thrower) at `target`. Returns (true, lines) if
+-- the net left the thrower's hand - whether it actually held anything or
+-- not - or (false, lines) if it never left the hand at all: the exact same
+-- two-outcome shape Throwing.resolve takes for a thrown weapon or potion.
+function Captives.resolve(game, thrower, item, target)
+  if not item or item.kind ~= Items.NET then
+    return false, { "that can't be thrown as a net" }
+  end
+  if not target or not target:isAlive() then
+    return false, { "no target" }
+  end
+  if not Captives.canReach(game.level.map, thrower.x, thrower.y, target.x, target.y) then
+    return false, { "you have no clear throw" }
+  end
+  if not Captives.eligible(target) then
+    return true, { target.name .. " is far too fierce to net while it can still fight like that" }
+  end
+  if not game.rng:chance(Captives.CATCH_NUMERATOR, Captives.CATCH_DENOMINATOR) then
+    return true, { target.name .. " thrashes free of the net" }
+  end
+  local captive = {
+    x = target.x, y = target.y,
+    species = target.species, faction = target.faction, name = target.name,
+    value = Captives.valueOf(target),
+  }
+  game.level.captives[#game.level.captives + 1] = captive
+  target.hp = 0
+  return true, { string.format("the net drops true - %s is bound and struggling", target.name) }
+end
+
+-- Drops `captive` off level.captives outright - shared by every way of
+-- spending one below, so a captive can never be resolved twice over.
+function Captives.remove(level, captive)
+  for i, candidate in ipairs(level.captives) do
+    if candidate == captive then
+      table.remove(level.captives, i)
+      return
+    end
+  end
+end
+
+-- Frees a held captive back to its own kind for nothing but goodwill: no
+-- gold changes hands, but its faction's standing warms by RANSOM_REP_GAIN -
+-- the mirror image of Factions.registerKill's penalty for finishing the
+-- same creature off outright, and the one resolution that can actually pull
+-- a tribal faction back out of Factions.isWary's hostile cutoff.
+function Captives.ransom(level, player, captive)
+  Captives.remove(level, captive)
+  return Factions.adjust(player, captive.faction, Captives.RANSOM_REP_GAIN)
+end
+
+-- Sells a held captive off for its own value in gold: word gets back to its
+-- kind either way, so standing sours by SELL_REP_LOSS even though - unlike
+-- an outright kill - nothing actually died to earn it.
+function Captives.sell(level, player, captive)
+  Captives.remove(level, captive)
+  player.gold = player.gold + captive.value
+  Factions.adjust(player, captive.faction, -Captives.SELL_REP_LOSS)
+  return captive.value
+end
+
+-- Interrogates a held captive instead of ransoming or selling it: no gold,
+-- no reputation swing either way, just whatever it gives up before its
+-- usefulness runs out - every currently-hidden secret door on this floor,
+-- found outright (see Secrets.revealAll), plus a trickle of essence for the
+-- trouble. Returns the doors this actually revealed, same as
+-- Secrets.revealAll itself.
+function Captives.interrogate(level, player, captive)
+  local revealed = Secrets.revealAll(level)
+  Captives.remove(level, captive)
+  player.essence = player.essence + math.max(1, captive.value // Captives.INTERROGATE_ESSENCE_DIVISOR)
+  return revealed
+end
+
+return Captives

src/challenges.lua

@@ -0,0 +1,69 @@
+-- Named challenge presets: a fixed class, a fixed mutator set and a
+-- deterministic seed, bound together so "today's challenge" means the same
+-- run for everyone who plays it - the daily-seed ritual familiar
+-- roguelikes build around, reproduced here without this module ever
+-- touching the wall clock itself (see Challenges.seedFor's own
+-- caller-supplied day index), so a test can pin any "day" it likes and get
+-- the exact same answer back every time.
+
+local Ascension = require("ascension")
+
+local Challenges = {}
+
+Challenges.CATALOG = {
+  { key = "iron_gauntlet", name = "Iron Gauntlet", class = "fighter", mutators = { "bloodbound" } },
+  { key = "arcane_sprint", name = "Arcane Sprint", class = "mage", mutators = { "famine" } },
+  { key = "shadow_creed", name = "Shadow Creed", class = "rogue", mutators = {} },
+  { key = "wild_hunt", name = "Wild Hunt", class = "ranger", mutators = { "nightblind" } },
+}
+
+Challenges.byKey = {}
+for _, def in ipairs(Challenges.CATALOG) do
+  Challenges.byKey[def.key] = def
+end
+
+-- A Knuth multiplicative hash of `dayIndex`, folded into the same 16-bit
+-- range warren.lua's own default seed (os.time() & 0xFFFF) already uses, so
+-- a challenge seed is never distinguishable from an ordinary one downstream.
+function Challenges.seedFor(dayIndex)
+  return (dayIndex * 2654435761) % 65536
+end
+
+-- The preset and seed "day `dayIndex`" always resolves to - a pure function
+-- of dayIndex alone, so the same day always hands out the same challenge to
+-- everyone who asks it, and a test can walk arbitrary days without waiting
+-- on a clock.
+function Challenges.forDay(dayIndex)
+  local preset = Challenges.CATALOG[(dayIndex % #Challenges.CATALOG) + 1]
+  return preset, Challenges.seedFor(dayIndex)
+end
+
+-- True iff `game` was actually played under `preset`'s own terms: started
+-- as its class, with every mutator it demands active (see
+-- Ascension.isActive) - extra mutators beyond the preset's own are fine,
+-- only a missing requirement fails it. Returns (false, reason) naming
+-- exactly what fell short, so a caller never has to re-derive why.
+function Challenges.satisfiedBy(preset, game)
+  if game.player.class ~= preset.class then
+    return false, "started as " .. tostring(game.player.class) .. " instead of " .. preset.class
+  end
+  for _, key in ipairs(preset.mutators) do
+    if not Ascension.isActive(game.ascension, key) then
+      return false, "missing mutator " .. key
+    end
+  end
+  return true, nil
+end
+
+-- One human-readable line describing `preset`: its display name, the class
+-- it demands, and every mutator it demands active - exactly the terms
+-- Challenges.satisfiedBy itself checks, spelled out for a player deciding
+-- whether to attempt it.
+function Challenges.describe(preset)
+  if #preset.mutators == 0 then
+    return string.format("%s (%s)", preset.name, preset.class)
+  end
+  return string.format("%s (%s + %s)", preset.name, preset.class, table.concat(preset.mutators, ", "))
+end
+
+return Challenges

src/chests.lua

@@ -0,0 +1,182 @@
+-- Lockable loot containers scattered through the dungeon: an unlocked chest
+-- yields its hoard the instant it is opened, a locked one demands either a
+-- spent key (Items.KEY, the same key a locked door already consumes) or a
+-- lockpick gamble (Items.LOCKPICK) that risks springing the chest's own trap
+-- on a failed pick - a second, riskier route into the same treasure rather
+-- than a strictly worse one, since a lockpick is commoner floor loot than a
+-- key. Only a locked chest can be trapped at all: there is no lock to punish
+-- fumbling with on one that was never going to resist in the first place.
+-- A chest never moves and never decays; once opened it stays on the map as
+-- an emptied husk exactly like a corpse past its last butchering, so a
+-- second visit finds nothing left to take. Chests are plain data on
+-- level.chests, exactly like level.corpses and level.nodes, so they
+-- serialize with no special save-format handling.
+
+local Items = require("items")
+local Affixes = require("affixes")
+local Status = require("status")
+
+local Chests = {}
+
+Chests.LOCK_CHANCE_NUMERATOR = 1
+Chests.LOCK_CHANCE_DENOMINATOR = 2
+
+Chests.TRAP_CHANCE_NUMERATOR = 1
+Chests.TRAP_CHANCE_DENOMINATOR = 3
+
+Chests.PICK_BASE_NUMERATOR = 1
+Chests.PICK_BASE_DENOMINATOR = 2
+Chests.PICK_LEVEL_BONUS_DIVISOR = 5
+
+Chests.TRAP_DART_MIN = 2
+Chests.TRAP_DART_MAX = 5
+
+Chests.GOLD_MIN_BONUS = 0
+Chests.GOLD_MAX_BONUS = 10
+Chests.GOLD_BASE = 10
+Chests.GOLD_PER_DEPTH = 6
+
+local chestWeapons = {
+  { name = "ornate rapier", power = 4 },
+  { name = "gilded axe",    power = 5 },
+}
+local chestArmors = {
+  { name = "banded mail", power = 3 },
+}
+
+-- One chest's hoard: always some gold plus a coin flip between a lightly
+-- affixed weapon or armor piece (see affixes.lua) and, half the time on top
+-- of that, a spare healing potion. Richer on average than a single floor
+-- drop (builder.lua's rollItem), since reaching it costs a key or a
+-- lockpick gamble rather than a free step onto its tile.
+local function rollLoot(rng, depth)
+  local loot = { Items.gold(Chests.GOLD_BASE + depth * Chests.GOLD_PER_DEPTH
+    + rng:range(Chests.GOLD_MIN_BONUS, Chests.GOLD_MAX_BONUS)) }
+  if rng:chance(1, 2) then
+    local base = chestWeapons[rng:range(1, #chestWeapons)]
+    loot[#loot + 1] = Affixes.decorate(Items.weapon(base.name, base.power + depth // 4), Affixes.rollWeapon(rng))
+  else
+    local base = chestArmors[rng:range(1, #chestArmors)]
+    loot[#loot + 1] = Affixes.decorate(Items.armor(base.name, base.power + depth // 4), Affixes.rollArmor(rng))
+  end
+  if rng:chance(1, 2) then
+    loot[#loot + 1] = Items.potionOf("heal")
+  end
+  return loot
+end
+
+-- A freshly rolled chest at (unassigned) x/y, exactly like Nodes.new -
+-- builder.lua stamps x/y directly onto the returned table once it finds a
+-- free cell for it. Trapped is only ever rolled for a locked chest (see
+-- above), so the rng stream is never touched by the trap roll at all on an
+-- unlocked one.
+function Chests.new(rng, depth)
+  local locked = rng:chance(Chests.LOCK_CHANCE_NUMERATOR, Chests.LOCK_CHANCE_DENOMINATOR)
+  local trapped = locked and rng:chance(Chests.TRAP_CHANCE_NUMERATOR, Chests.TRAP_CHANCE_DENOMINATOR)
+  return {
+    locked = locked,
+    trapped = trapped,
+    opened = false,
+    loot = rollLoot(rng, depth),
+  }
+end
+
+-- A chest still worth forcing: locked and not already emptied. An opened
+-- chest reports unlocked regardless of its own `locked` flag, since nothing
+-- is left inside to gate.
+function Chests.isLocked(chest)
+  return chest.locked and not chest.opened
+end
+
+-- Odds of a lockpick attempt succeeding: a flat coin flip that improves
+-- slightly with player level, capped a point shy of the denominator so a
+-- pick attempt is never a sure thing no matter how experienced the player
+-- gets - mirrors disarm.lua's Disarm.oddsFor.
+function Chests.oddsFor(player)
+  local numerator = Chests.PICK_BASE_NUMERATOR + player.level // Chests.PICK_LEVEL_BONUS_DIVISOR
+  if numerator > Chests.PICK_BASE_DENOMINATOR - 1 then
+    numerator = Chests.PICK_BASE_DENOMINATOR - 1
+  end
+  return numerator, Chests.PICK_BASE_DENOMINATOR
+end
+
+-- Pours every item in `chest`'s hoard into `player`'s inventory and marks
+-- the chest spent for good.
+local function grant(player, chest)
+  for _, item in ipairs(chest.loot) do
+    player.inventory[#player.inventory + 1] = item
+  end
+  chest.opened = true
+  chest.loot = {}
+end
+
+-- Opens an already-unlocked (or never-locked) chest outright. Refuses with
+-- (false, line) and no state change against one still locked or already
+-- emptied - the caller (Game:openChest) routes a locked chest through
+-- Chests.unlockWithKey or Chests.pick instead.
+function Chests.open(player, chest)
+  if chest.opened then return false, "this chest is already empty" end
+  if Chests.isLocked(chest) then return false, "the chest is locked" end
+  grant(player, chest)
+  return true, "you open the chest and take its hoard"
+end
+
+-- Spends a key from `player`'s inventory to force the lock outright, no
+-- roll involved - the same certain trade a locked door already makes for
+-- one of Items.KEY. Returns (false, line) with nothing spent if the player
+-- is not carrying one, or against a chest that is not actually locked.
+function Chests.unlockWithKey(player, chest)
+  if not Chests.isLocked(chest) then return false, "this chest has no lock to open" end
+  for i, item in ipairs(player.inventory) do
+    if item.kind == Items.KEY then
+      table.remove(player.inventory, i)
+      chest.locked = false
+      grant(player, chest)
+      return true, "you unlock the chest with your key"
+    end
+  end
+  return false, "you have no key"
+end
+
+-- A trapped chest's punishment for a failed pick: a dart to the ribs or a
+-- dose of poison, the same two effects a floor trap can spring (see
+-- game.lua's Game:springTrap) but resolved locally since a chest is not a
+-- level.traps entry. Spends the trap the instant it springs - a chest only
+-- ever bites back once.
+function Chests.springTrap(game, chest)
+  chest.trapped = false
+  local player = game.player
+  if game.rng:chance(1, 2) then
+    local dealt = game.rng:range(Chests.TRAP_DART_MIN, Chests.TRAP_DART_MAX)
+    player.hp = player.hp - dealt
+    return string.format("a needle trap jabs you for %d", dealt)
+  end
+  Status.apply(player, Status.POISON, 5, 2)
+  return "a cloud of poison bursts from the lock"
+end
+
+-- Gambles a lockpick against `chest`'s lock. Always spends the pick, win or
+-- lose, once one is found. On success the chest opens exactly like
+-- Chests.unlockWithKey; on failure a trapped chest springs on the player
+-- (Chests.springTrap) while an untrapped one merely wastes the pick, the
+-- lock still standing for a later key or another pick.
+function Chests.pick(game, chest)
+  local player = game.player
+  if not Chests.isLocked(chest) then return false, "this chest has no lock to pick" end
+  local pickIndex
+  for i, item in ipairs(player.inventory) do
+    if item.kind == Items.LOCKPICK then pickIndex = i; break end
+  end
+  if not pickIndex then return false, "you have no lockpicks" end
+  table.remove(player.inventory, pickIndex)
+  local numerator, denominator = Chests.oddsFor(player)
+  if not game.rng:chance(numerator, denominator) then
+    if chest.trapped then return false, Chests.springTrap(game, chest) end
+    return false, "your lockpick slips and the lock holds"
+  end
+  chest.locked = false
+  grant(player, chest)
+  return true, "your lockpick clicks the lock open"
+end
+
+return Chests

src/classes.lua

@@ -0,0 +1,64 @@
+-- Player classes. A class is chosen once at character creation (Game.new
+-- options.class) and never changes; it grants a one-time stat or kit delta
+-- and, through skills.lua, gates which skills the player is allowed to spend
+-- points on. Classless play (no options.class given) is unaffected - every
+-- class delta is opt-in so existing unclassed games keep their exact stats.
+
+local Items = require("items")
+
+local Classes = {}
+
+Classes.order = { "fighter", "rogue", "mage", "ranger" }
+
+Classes.defs = {
+  fighter = {
+    name = "fighter",
+    apply = function(player)
+      player.maxHp = player.maxHp + 8
+      player.hp = player.hp + 8
+      player.attack = player.attack + 2
+      player.baseAttack = player.baseAttack + 2
+    end,
+  },
+  rogue = {
+    name = "rogue",
+    apply = function(player)
+      player.gold = player.gold + 15
+      player.attack = player.attack + 1
+      player.baseAttack = player.baseAttack + 1
+    end,
+  },
+  mage = {
+    name = "mage",
+    apply = function(player)
+      player.maxMana = player.maxMana + 8
+      player.mana = player.mana + 8
+      player.attack = player.attack - 1
+      player.baseAttack = player.baseAttack - 1
+    end,
+  },
+  ranger = {
+    name = "ranger",
+    apply = function(player)
+      Items.equipBow(Items.bow("shortbow", 3, 6), player)
+      player.inventory[#player.inventory + 1] = Items.ammo("arrow", 12)
+    end,
+  },
+}
+
+function Classes.isValid(key)
+  return Classes.defs[key] ~= nil
+end
+
+-- Applies the one-time delta for `key` to a freshly created player. Must run
+-- after the player's base stats, mana pool and starting inventory are all in
+-- place, since every delta is additive on top of whatever is already there.
+function Classes.apply(player, key)
+  local def = Classes.defs[key]
+  if not def then return false end
+  player.class = key
+  def.apply(player)
+  return true
+end
+
+return Classes

src/combat.lua

@@ -1,24 +1,53 @@
 -- Deterministic combat: damage is effective attack minus effective defense,
--- floored at 1. Effective stats fold in temporary status modifiers.
+-- floored at 1. Effective stats fold in temporary status modifiers, plus
+-- conditional skill bonuses (berserk/mana shield - see skills.lua, a no-op
+-- for any entity without a `skills` table, i.e. monsters) and any completed
+-- runeword on the wielder's own weapon/armor (see runewords.lua, a no-op for
+-- any item without a matching rune chain), plus any item-set threshold the
+-- wielder's current gear happens to meet (see sets.lua, a no-op below its
+-- lowest 2-piece threshold).
+-- The attack-minus-defense minimum-1 floor happens before elemental
+-- resistance (resistances.lua) gets a say, so a defender immune to the
+-- attack's damage type can still shrug off a hit that combat itself
+-- guaranteed would land.
+
+local Skills = require("skills")
+local Resistances = require("resistances")
+local Runewords = require("runewords")
+local Sets = require("sets")
 
 local Combat = {}
 
 local function attackOf(entity)
-  return entity.effectiveAttack and entity:effectiveAttack() or entity.attack
+  local base = entity.effectiveAttack and entity:effectiveAttack() or entity.attack
+  return base + Skills.attackBonus(entity) + Runewords.attackBonus(entity) + Sets.attackBonus(entity)
 end
 
 local function defenseOf(entity)
-  return entity.effectiveDefense and entity:effectiveDefense() or entity.defense
+  local base = entity.effectiveDefense and entity:effectiveDefense() or entity.defense
+  return base + Skills.defenseBonus(entity) + Runewords.defenseBonus(entity) + Sets.defenseBonus(entity)
 end
 
-function Combat.damage(attacker, defender)
-  local dealt = attackOf(attacker) - defenseOf(defender)
+-- The type of an attacker's raw damage: a weapon retagged by an elemental
+-- affix (flaming/venomed - see affixes.lua) fights with that element instead
+-- of a bare fist or claw's plain physical.
+local function damageTypeOf(attacker)
+  return (attacker.weapon and attacker.weapon.damageType) or Resistances.PHYSICAL
+end
+
+-- `multiplier` scales the raw attack-minus-defense difference before the
+-- floor-at-1 minimum is applied, so a backstab still guarantees at least 1
+-- rather than 2x-ing an already-clamped hit. `damageType` defaults to the
+-- attacker's own weapon typing when omitted.
+function Combat.damage(attacker, defender, multiplier, damageType)
+  local dealt = (attackOf(attacker) - defenseOf(defender)) * (multiplier or 1)
   if dealt < 1 then dealt = 1 end
-  return dealt
+  dealt = math.floor(dealt)
+  return Resistances.apply(defender, dealt, damageType or damageTypeOf(attacker))
 end
 
-function Combat.attack(attacker, defender)
-  local dealt = Combat.damage(attacker, defender)
+function Combat.attack(attacker, defender, multiplier, damageType)
+  local dealt = Combat.damage(attacker, defender, multiplier, damageType)
   defender.hp = defender.hp - dealt
   return { damage = dealt, killed = defender.hp <= 0 }
 end

src/commands.lua

@@ -0,0 +1,625 @@
+-- Text command parser and dispatcher for a human player, layered entirely on
+-- top of the granular Game:<action> methods choosePlayerAction (ai.lua's own
+-- autopilot) already drives - nothing here duplicates combat, targeting or
+-- turn bookkeeping, it only translates a typed word into the same call the
+-- autopilot would have made. Every other player-facing system in this engine
+-- is a mechanic; this is the one module whose whole job is the interface
+-- between a line of text and those mechanics, which is why it takes `game`
+-- as a plain argument rather than requiring game.lua itself (that require
+-- runs the other way, from game.lua's Game:manualStep).
+--
+-- Commands.apply(game, text) always returns (consumesTurn, message): a
+-- movement/action word that actually did something returns true and leaves
+-- Game:manualStep to spend the turn, exactly like choosePlayerAction would
+-- have; an unrecognized word, a bad argument, or an action with nothing to
+-- act on returns false and spends nothing, so a typo never costs a turn the
+-- way a wasted keystroke would in any other roguelike. Purely informational
+-- commands (inventory, look, status, help) always return false for the same
+-- reason - reading your own inventory is free.
+
+local Spells = require("spells")
+local Identify = require("identify")
+local Factions = require("factions")
+local Examine = require("examine")
+local Skills = require("skills")
+
+local Commands = {}
+
+local DIRS = {
+  north = { 0, -1 }, n = { 0, -1 },
+  south = { 0, 1 }, s = { 0, 1 },
+  east = { 1, 0 }, e = { 1, 0 },
+  west = { -1, 0 }, w = { -1, 0 },
+  northeast = { 1, -1 }, ne = { 1, -1 },
+  northwest = { -1, -1 }, nw = { -1, -1 },
+  southeast = { 1, 1 }, se = { 1, 1 },
+  southwest = { -1, 1 }, sw = { -1, 1 },
+}
+
+-- Splits `text` on whitespace into a lowercase verb plus its remaining
+-- tokens as args. Returns nil for anything with no verb at all (an empty or
+-- all-whitespace line), which Commands.apply treats the same as an unknown
+-- command - no turn spent either way.
+function Commands.parse(text)
+  if type(text) ~= "string" then return nil end
+  local tokens = {}
+  for token in text:gmatch("%S+") do
+    tokens[#tokens + 1] = token:lower()
+  end
+  if #tokens == 0 then return nil end
+  local args = {}
+  for i = 2, #tokens do args[#args + 1] = tokens[i] end
+  return { verb = tokens[1], args = args }
+end
+
+-- A monster the player can actually see right now: alive, kind "monster"
+-- (excludes the player's own companions/hirelings/thralls, which never
+-- carry that kind - see game.lua's isPlayerAlly), and standing on a tile
+-- game.visible already marks lit for the player this turn.
+local function isVisibleHostile(game, entity)
+  return entity.kind == "monster" and entity:isAlive()
+    and game.visible[game.level.map:index(entity.x, entity.y)] == true
+end
+
+-- Up to `count` nearest visible hostiles, Chebyshev distance, ties broken by
+-- ascending id - the same tie rule Game:nearestAlly and companions.lua's own
+-- nearestHostile already use, so auto-targeting a ranged command picks
+-- exactly the monster the autopilot would have picked in the same spot.
+local function nearestHostiles(game, count)
+  local player = game.player
+  local results, excluded = {}, {}
+  for _ = 1, count do
+    local best, bestDist
+    for _, entity in ipairs(game.level.entities) do
+      if not excluded[entity] and isVisibleHostile(game, entity) then
+        local dist = math.max(math.abs(entity.x - player.x), math.abs(entity.y - player.y))
+        if not best or dist < bestDist or (dist == bestDist and entity.id < best.id) then
+          best, bestDist = entity, dist
+        end
+      end
+    end
+    if not best then break end
+    results[#results + 1] = best
+    excluded[best] = true
+  end
+  return results
+end
+
+local function nearestHostile(game)
+  return nearestHostiles(game, 1)[1]
+end
+
+-- Every visible hostile in game.level.entities's own order, unlike
+-- nearestHostiles above which sorts by distance - this is the order
+-- Handlers.look numbers its list in, so "examine monster <n>" always means
+-- the same monster the player just saw look print at that number.
+local function visibleHostilesInOrder(game)
+  local list = {}
+  for _, entity in ipairs(game.level.entities) do
+    if isVisibleHostile(game, entity) then list[#list + 1] = entity end
+  end
+  return list
+end
+
+-- Resolves an optional trailing target number - the exact 1-based index
+-- Handlers.look/examine already print next to each visible hostile - to an
+-- entity, falling back to the nearest visible hostile (the old, only
+-- behaviour) when the caller omitted it. Every targeted handler below stays
+-- correct for a player who never bothers naming a target, while letting a
+-- player who cares (a dangerous archer standing behind an expendable rat)
+-- reach past the default without any change to game.lua's own range/line-of-
+-- sight checks, which still reject an out-of-reach explicit target exactly
+-- like they already reject a too-far auto-picked one.
+-- Returns (target, explicit): explicit is true only when the caller actually
+-- passed a token for the slot, so callers can tell "you named a target that
+-- is not there" apart from "there is no target in sight at all" and keep
+-- their own existing wording for the latter.
+local function resolveTarget(game, indexText)
+  if indexText == nil then return nearestHostile(game), false end
+  local index = tonumber(indexText)
+  return index and visibleHostilesInOrder(game)[index], true
+end
+
+-- Commands.parse lowercases every token before a handler ever sees it, which
+-- is harmless for directions/spells/factions/slots (already all-lowercase
+-- keys) but not for Skills.active/Skills.passive, whose keys are camelCase
+-- (secondWind, poisonBlade, manaShield) - a player typing the skill's own
+-- name would otherwise never match it. Maps a lowercased word back to its
+-- real key by case-insensitive scan; returns the word unchanged when nothing
+-- matches, so an actually unknown skill still reaches Skills.use/Skills.learn
+-- and gets their own "no such skill" wording instead of being swallowed here.
+local function resolveSkillKey(word)
+  if not word then return word end
+  for key in pairs(Skills.active) do
+    if key:lower() == word then return key end
+  end
+  for key in pairs(Skills.passive) do
+    if key:lower() == word then return key end
+  end
+  return word
+end
+
+local Handlers = {}
+
+local function moveHandler(dx, dy)
+  return function(game)
+    if game:movePlayer(dx, dy) then return true, nil end
+    return false, "you cannot go that way"
+  end
+end
+
+for name, dir in pairs(DIRS) do
+  Handlers[name] = moveHandler(dir[1], dir[2])
+end
+
+Handlers.attack = function(game, args)
+  local dir = DIRS[args[1]]
+  if not dir then return false, "attack which direction?" end
+  if game:movePlayer(dir[1], dir[2]) then return true, nil end
+  return false, "there is nothing to attack there"
+end
+
+Handlers.wait = function() return true, "you wait" end
+Handlers.z = Handlers.wait
+Handlers["."] = Handlers.wait
+
+Handlers.pickup = function(game)
+  game:pickupHere()
+  return true, nil
+end
+Handlers.g = Handlers.pickup
+
+-- Game:autoExplore already returns the exact (consumesTurn, message) shape
+-- every handler here does - it just may have spent several turns getting
+-- there instead of one, stopping itself the moment a hostile comes into
+-- sight or the player takes damage rather than walking on regardless.
+Handlers.explore = function(game)
+  return game:autoExplore()
+end
+
+-- Game:restUntilHealed shares the same shape and the same "may spend several
+-- turns before returning" behaviour as Game:autoExplore just above.
+Handlers.rest = function(game)
+  return game:restUntilHealed()
+end
+
+-- Game:travelTo shares that same "may spend several turns" shape too. "down"/
+-- "up" are the level's own stairs (self.level.downX/Y, upX/Y) - always a
+-- valid, already-walkable destination regardless of what the player has
+-- explored yet, exactly like choosePlayerAction's own goal-seeking already
+-- assumes; a raw x/y command is deliberately not offered since nothing in
+-- this interface ever shows the player a raw coordinate to aim one at.
+Handlers.travel = function(game, args)
+  if args[1] == "down" then return game:travelTo(game.level.downX, game.level.downY) end
+  if args[1] == "up" then return game:travelTo(game.level.upX, game.level.upY) end
+  return false, "travel where? down or up"
+end
+
+-- Every handler below that takes an inventory index shares the same shape:
+-- a missing or non-numeric first arg fails without spending a turn, exactly
+-- like an unknown verb, rather than crashing into the underlying Game
+-- method with a nil index.
+local function indexArg(args)
+  return tonumber(args[1])
+end
+
+Handlers.use = function(game, args)
+  local index = indexArg(args)
+  if not index then return false, "use what? give an inventory number" end
+  if game:useItem(index) then return true, nil end
+  return false, "you cannot use that"
+end
+Handlers.u = Handlers.use
+
+Handlers.drop = function(game, args)
+  local index = indexArg(args)
+  if not index then return false, "drop what? give an inventory number" end
+  if game:dropItem(index) then return true, nil end
+  return false, "you have nothing there to drop"
+end
+
+Handlers.sell = function(game, args)
+  local index = indexArg(args)
+  if not index then return false, "sell what? give an inventory number" end
+  if game:sellItem(index) then return true, nil end
+  return false, "that cannot be sold here"
+end
+
+-- Trailing target number is always the argument slot right after whatever
+-- an individual handler needed for itself (an inventory index, a spell/skill
+-- key) - see resolveTarget above for exactly what "explicit" changes.
+Handlers.throw = function(game, args)
+  local index = indexArg(args)
+  if not index then return false, "throw what? give an inventory number" end
+  local target, explicit = resolveTarget(game, args[2])
+  if not target then
+    if explicit then return false, "no monster in sight at that number" end
+    return false, "there is nothing in sight to throw at"
+  end
+  if game:throwAt(index, target) then return true, nil end
+  return false, "you cannot throw that"
+end
+
+Handlers.capture = function(game, args)
+  local index = indexArg(args)
+  if not index then return false, "capture with what? give an inventory number" end
+  local target, explicit = resolveTarget(game, args[2])
+  if not target then
+    if explicit then return false, "no monster in sight at that number" end
+    return false, "there is nothing in sight to capture"
+  end
+  if game:captureAt(index, target) then return true, nil end
+  return false, "the capture attempt fails"
+end
+
+Handlers.fire = function(game, args)
+  local target, explicit = resolveTarget(game, args[1])
+  if not target then
+    if explicit then return false, "no monster in sight at that number" end
+    return false, "there is nothing in sight to fire at"
+  end
+  if game:fireAt(target) then return true, nil end
+  return false, "you cannot fire right now"
+end
+
+Handlers.cast = function(game, args)
+  local key = args[1]
+  if not key then return false, "cast what spell?" end
+  local def = Spells.catalog[key]
+  if not def then return false, "you know no spell by that name" end
+  local target = nil
+  if def.targeted then
+    local explicit
+    target, explicit = resolveTarget(game, args[2])
+    if not target then
+      if explicit then return false, "no monster in sight at that number" end
+      return false, "there is nothing in sight to cast that at"
+    end
+  end
+  if game:castSpell(key, target) then return true, nil end
+  return false, "the spell fails"
+end
+
+-- multishot's two targets are named together or not at all: giving only one
+-- explicit number is ambiguous about which of the (up to) two shots it picks
+-- out, so that case falls back to the same auto-pick-both-nearest behaviour
+-- as giving none, rather than guessing which slot the player meant.
+Handlers.useskill = function(game, args)
+  local key = resolveSkillKey(args[1])
+  if not key then return false, "use which skill?" end
+  local success
+  if key == "cleave" then
+    local target, explicit = resolveTarget(game, args[2])
+    if not target and explicit then return false, "no monster in sight at that number" end
+    success = game:useSkill(key, target)
+  elseif key == "multishot" then
+    if args[2] and args[3] then
+      local list = visibleHostilesInOrder(game)
+      local t1, t2 = list[tonumber(args[2]) or -1], list[tonumber(args[3]) or -1]
+      if not t1 or not t2 then return false, "no monster in sight at that number" end
+      success = game:useSkill(key, t1, t2)
+    else
+      local targets = nearestHostiles(game, 2)
+      success = game:useSkill(key, targets[1], targets[2])
+    end
+  else
+    success = game:useSkill(key)
+  end
+  if success then return true, nil end
+  return false, "that skill fails"
+end
+
+-- Zero-argument actions that always resolve against whatever stands on the
+-- player's own tile (a chest, a corpse, a captive, a node, a stairwell...),
+-- the same way every one of these Game methods already looks itself up by
+-- self.player.x/y rather than taking a target. `nothingMessage` only ever
+-- surfaces when the underlying method itself failed silently (no log line
+-- of its own) - most branches already explain themselves through game.log.
+local function hereHandler(methodName, nothingMessage)
+  return function(game)
+    if game[methodName](game) then return true, nil end
+    return false, nothingMessage
+  end
+end
+
+Handlers.open = hereHandler("openChest", "there is nothing here to open")
+Handlers.butcher = hereHandler("butcherCorpse", "there is nothing here to butcher")
+Handlers.raise = hereHandler("raiseCorpse", "there is nothing here to raise")
+Handlers.scavenge = hereHandler("scavengeCorpse", "there is nothing here to scavenge")
+Handlers.harvest = hereHandler("harvestNode", "there is nothing here to harvest")
+Handlers.ransom = hereHandler("ransomCaptive", "there is nothing here to ransom")
+Handlers.sellcaptive = hereHandler("sellCaptive", "there is nothing here to sell")
+Handlers.interrogate = hereHandler("interrogateCaptive", "there is nothing here to interrogate")
+Handlers.descend = hereHandler("descend", "there are no stairs down here")
+Handlers[">"] = Handlers.descend
+Handlers.ascend = hereHandler("ascend", "there are no stairs up here")
+Handlers["<"] = Handlers.ascend
+Handlers.enterrift = hereHandler("enterRift", "there is no rift here to cross")
+Handlers.exitrift = hereHandler("exitRift", "you are not standing across a rift")
+
+-- Game:startHorde is a deliberate, one-way trial (see its own header: the
+-- dungeon floor left behind is simply abandoned, there is no exit back) that
+-- always succeeds and, unlike every hereHandler above, carries no location
+-- requirement of its own - so this guards against the one real footgun a
+-- typed command adds that the method itself does not: retyping "horde"
+-- mid-run would otherwise silently discard the current wave and its
+-- progress by building a brand new arena on top of it.
+Handlers.horde = function(game)
+  if game.horde then return false, "you are already fighting in the arena" end
+  game:startHorde()
+  return true, nil
+end
+
+Handlers.pray = function(game)
+  local shrine = game.level:shrineAt(game.player.x, game.player.y)
+  if not shrine then return false, "there is no shrine here" end
+  if game:prayAt(shrine) then return true, nil end
+  return false, "your prayer goes unanswered"
+end
+
+Handlers.quest = function(game)
+  local board = game.level:questBoardAt(game.player.x, game.player.y)
+  if not board then return false, "there is no quest board here" end
+  if game:tryAcceptQuest(board) then return true, nil end
+  return false, "you cannot take up that bounty"
+end
+
+-- Every faction key factions.lua defines, spelled out here (rather than
+-- discovered from the module at runtime) purely so a bad argument's error
+-- message can list them by name; the set itself is built from the same
+-- constants Game:appeaseFaction already trusts, so a typo can never buy
+-- standing with a faction that does not exist.
+local FACTION_NAMES = {
+  Factions.MERCHANT, Factions.GOBLINOID, Factions.VERMIN, Factions.ORCISH,
+  Factions.UNDEAD, Factions.BEAST, Factions.CULT, Factions.DRAKE, Factions.BANDIT,
+}
+local FACTION_SET = {}
+for _, name in ipairs(FACTION_NAMES) do FACTION_SET[name] = true end
+
+Handlers.appease = function(game, args)
+  local faction = args[1]
+  if not faction or not FACTION_SET[faction] then
+    return false, "appease which faction? " .. table.concat(FACTION_NAMES, ", ")
+  end
+  if game:appeaseFaction(faction) then return true, nil end
+  return false, nil
+end
+
+Handlers.dig = function(game, args)
+  local dir = DIRS[args[1]]
+  if not dir then return false, "dig which direction?" end
+  if game:dig(dir[1], dir[2]) then return true, nil end
+  return false, "you cannot dig there"
+end
+
+-- Disarms a detected-but-unsprung trap one step away in `dir` - the same
+-- Chebyshev-1 reach Disarm.sweep already uses to notice it in the first
+-- place (see Game:endPlayerTurn's "you notice a hidden trap nearby"). The
+-- validity check below duplicates Game:disarmTrap's own guard on purpose:
+-- unlike every other handler here, a disarm attempt against a real trap
+-- must still spend the turn even when Disarm.attempt fails and springs it,
+-- but Game:disarmTrap's own boolean return conflates that spring with "no
+-- trap here" into the same false - so this handler tells the two apart
+-- itself instead of trusting the method's return value for turn cost.
+Handlers.disarm = function(game, args)
+  local dir = DIRS[args[1]]
+  if not dir then return false, "disarm which direction?" end
+  local trap = game.level:trapAt(game.player.x + dir[1], game.player.y + dir[2])
+  if not trap or not trap.detected or trap.revealed then
+    return false, "there is nothing here you have noticed to disarm"
+  end
+  game:disarmTrap(trap)
+  return true, nil
+end
+
+-- Crafting/economy verbs (game.lua's forgeGem/mergeGemsAt/socketItem/
+-- socketRune/temperItem/enchantItem/disenchantItem/repairEquipped/
+-- stealFromShop/dismissHireling/learnSkill/brewAt), the other half of the
+-- API choosePlayerAction can already reach that a typed session could not
+-- until now. Every one of these Game methods already logs its own success
+-- or failure reason, so a handler only needs its own message for an
+-- argument so malformed the underlying method can never even be called.
+
+-- Shared by socket/socketrune/temper/enchant/disenchant: their `target`
+-- resolves through Game:resolveGear exactly like this, either the literal
+-- word for currently equipped gear or an inventory slot number for
+-- anything else (a spare ring, an unequipped bow).
+local function targetArg(token)
+  if token == "weapon" or token == "armor" then return token end
+  return tonumber(token)
+end
+
+Handlers.forge = function(game, args)
+  local element = args[1]
+  if not element then return false, "forge which element? fire, frost, shock or venom" end
+  if game:forgeGem(element) then return true, nil end
+  return false, nil
+end
+
+Handlers.merge = function(game, args)
+  local a, b = tonumber(args[1]), tonumber(args[2])
+  if not a or not b then return false, "merge which two gems? give two inventory numbers" end
+  if game:mergeGemsAt(a, b) then return true, nil end
+  return false, "those cannot be merged"
+end
+
+Handlers.socket = function(game, args)
+  local target, gemIndex = targetArg(args[1]), tonumber(args[2])
+  if not target or not gemIndex then
+    return false, "socket what into what? give a target (weapon/armor/item number) and a gem number"
+  end
+  if game:socketItem(target, gemIndex) then return true, nil end
+  return false, "that cannot be socketed"
+end
+
+Handlers.socketrune = function(game, args)
+  local target, runeIndex = targetArg(args[1]), tonumber(args[2])
+  if not target or not runeIndex then
+    return false, "socket which rune into what? give a target (weapon/armor/item number) and a rune number"
+  end
+  if game:socketRune(target, runeIndex) then return true, nil end
+  return false, "that cannot be socketed"
+end
+
+Handlers.temper = function(game, args)
+  local target = targetArg(args[1])
+  if not target then return false, "temper what? weapon, armor or an item number" end
+  if game:temperItem(target) then return true, nil end
+  return false, "that cannot be tempered"
+end
+
+Handlers.enchant = function(game, args)
+  local target, affixKey = targetArg(args[1]), args[2]
+  if not target or not affixKey then
+    return false, "enchant what with what? give a target (weapon/armor/item number) and an affix name"
+  end
+  if game:enchantItem(target, affixKey) then return true, nil end
+  return false, "that cannot be enchanted"
+end
+
+Handlers.disenchant = function(game, args)
+  local target = targetArg(args[1])
+  if not target then return false, "disenchant what? weapon, armor or an item number" end
+  if game:disenchantItem(target) then return true, nil end
+  return false, "that cannot be disenchanted"
+end
+
+Handlers.repair = function(game, args)
+  local slot = args[1]
+  if slot ~= "weapon" and slot ~= "armor" and slot ~= "bow" then
+    return false, "repair what? weapon, armor or bow"
+  end
+  if game:repairEquipped(slot) then return true, nil end
+  return false, nil
+end
+
+-- Steals whichever warded ware sits underfoot, the same tile Game:pickupHere
+-- already resolves against - unlike Game:stealFromShop's own raw floorItems
+-- index, a typed command can only ever mean "the ware I am standing on".
+local function groundIndexHere(game)
+  for i, ground in ipairs(game.level.floorItems) do
+    if ground.x == game.player.x and ground.y == game.player.y then return i, ground end
+  end
+  return nil
+end
+
+Handlers.steal = function(game)
+  local index = groundIndexHere(game)
+  if index and game:stealFromShop(index) then return true, nil end
+  return false, "there is nothing here worth stealing"
+end
+
+Handlers.dismiss = function(game)
+  if game:dismissHireling() then return true, nil end
+  return false, nil
+end
+
+Handlers.learn = function(game, args)
+  local key = resolveSkillKey(args[1])
+  if not key then return false, "learn which skill?" end
+  game:learnSkill(key)
+  return false, nil
+end
+
+-- Duplicates Game:brewAt's own precondition checks (cauldron underfoot, two
+-- distinct herb items) before ever calling it, the same shape as disarm
+-- above and for the same reason: past those preconditions, brewing always
+-- spends both herbs, whether the pairing brews a potion or curdles into gas
+-- (see Alchemy.brew), so this handler must not read a curdle's own `false`
+-- as "nothing happened" and hand the player a free turn back.
+Handlers.brew = function(game, args)
+  local a, b = tonumber(args[1]), tonumber(args[2])
+  if not a or not b then return false, "brew which two herbs? give two inventory numbers" end
+  if not game.level:cauldronAt(game.player.x, game.player.y) then
+    return false, "there is no cauldron here"
+  end
+  if a == b then return false, "brew two different herbs, not the same one twice" end
+  local herbA, herbB = game.player.inventory[a], game.player.inventory[b]
+  if not herbA or not herbB or herbA.kind ~= "herb" or herbB.kind ~= "herb" then
+    return false, "you need two herbs to brew"
+  end
+  game:brewAt(a, b)
+  return true, nil
+end
+
+-- Purely informational commands. Every one of these returns false (spends no
+-- turn) and carries its whole answer in the message, which is the one place
+-- a caller should print something the game log itself would never contain.
+Handlers.inventory = function(game)
+  if #game.player.inventory == 0 then return false, "you are carrying nothing" end
+  local lines = {}
+  for i, item in ipairs(game.player.inventory) do
+    lines[#lines + 1] = string.format("  %d) %s", i, Identify.label(game.identify, item))
+  end
+  return false, table.concat(lines, "\n")
+end
+Handlers.i = Handlers.inventory
+
+Handlers.status = function(game)
+  local p = game.player
+  return false, string.format(
+    "hp %d/%d  mana %d/%d  gold %d  essence %d  level %d  xp %d/%d  depth %d  turn %d",
+    p.hp, p.maxHp, p.mana or 0, p.maxMana or 0, p.gold, p.essence,
+    p.level, p.xp, p.xpNext, game.depth, game.turn)
+end
+
+Handlers.look = function(game)
+  local targets = visibleHostilesInOrder(game)
+  if #targets == 0 then return false, "you see no threats nearby" end
+  local names = {}
+  for i, entity in ipairs(targets) do
+    names[#names + 1] = string.format("%d) %s", i, entity.name)
+  end
+  return false, "in sight: " .. table.concat(names, ", ")
+end
+Handlers.l = Handlers.look
+
+-- Detail views (examine.lua): `examine <n>` inspects inventory item n, the
+-- same index use/drop/sell already key off; `examine monster <n>` inspects
+-- the nth entry of the very list Handlers.look just numbered. Both branches
+-- are free, like every other informational command here.
+Handlers.examine = function(game, args)
+  if args[1] == "monster" then
+    local index = tonumber(args[2])
+    if not index then return false, "examine which monster? give the number look showed you" end
+    local target = visibleHostilesInOrder(game)[index]
+    if not target then return false, "no monster in sight at that number" end
+    return false, Examine.monster(game.player, target)
+  end
+  local index = indexArg(args)
+  if not index then return false, "examine what? give an inventory number, or 'monster <n>'" end
+  local item = game.player.inventory[index]
+  if not item then return false, "you are not carrying anything at that number" end
+  return false, Examine.item(game.identify, item)
+end
+Handlers.x = Handlers.examine
+
+Handlers.help = function()
+  return false, "commands: north/south/east/west/ne/nw/se/sw (or n/s/e/w/...), attack <dir>, " ..
+    "wait, pickup, explore, rest, travel down/up, inventory, use <n>, drop <n>, sell <n>, throw <n> [target], " ..
+    "fire [target], capture <n> [target], cast <spell> [target], useskill <skill> [target], " ..
+    "open, pray, quest, appease <faction>, butcher, raise, " ..
+    "scavenge, harvest, ransom, sellcaptive, interrogate, dig <dir>, disarm <dir>, " ..
+    "descend, ascend, enterrift, exitrift, horde, " ..
+    "steal, dismiss, learn <skill>, forge <element>, merge <a> <b>, brew <a> <b>, " ..
+    "socket <target> <gem>, socketrune <target> <rune>, temper <target>, " ..
+    "enchant <target> <affix>, disenchant <target>, repair <slot>, " ..
+    "examine <n>, examine monster <n>, look, status, help " ..
+    "([target] is the number look/examine gives a monster; omit it to auto-target the nearest one)"
+end
+
+-- Parses `text` and dispatches it against `game`. Returns (consumesTurn,
+-- message): Game:manualStep spends the player's turn iff the first value is
+-- true, and either surfaces `message` itself (a failure reason, or an
+-- informational answer) or leaves the game log to speak for a successful
+-- action, exactly the way every Game:<action> method already logs its own
+-- outcome.
+function Commands.apply(game, text)
+  local parsed = Commands.parse(text)
+  if not parsed then return false, "say something" end
+  local handler = Handlers[parsed.verb]
+  if not handler then return false, "unknown command: " .. parsed.verb end
+  return handler(game, parsed.args)
+end
+
+return Commands

src/companions.lua

@@ -0,0 +1,188 @@
+-- Player-aligned allies bonded from a charm found on the floor. Once summoned
+-- a companion joins the turn scheduler exactly like a monster (see game.lua's
+-- takeMonsterTurn), but its own turn logic below hunts nearby hostile
+-- monsters instead of the player and never turns hostile itself. Only one
+-- companion may be bonded at a time - summoning a second retires the first.
+--
+-- Static per-species numbers (sight radius, heal rate) are looked up from
+-- Companions.byKey by species key rather than copied onto the entity, the
+-- same convention monsters.lua uses for xp: one source of truth, and nothing
+-- extra to add to entity.lua's serialization whitelist. A companion's own
+-- battle-earned progress (companionXp/companionLevel/companionHealBonus
+-- below) is the opposite: per-instance and mutable, so unlike the static
+-- table above it does need its own prefixed trio in that whitelist, the same
+-- way mercenaries.lua's wage/loyalty or reanimation.lua's decay already do.
+
+local Entity = require("entity")
+local Combat = require("combat")
+local Los = require("los")
+local Monsters = require("monsters")
+local Status = require("status")
+local Noise = require("noise")
+
+local Companions = {}
+
+-- `evolutions` entries are climbed in order, each permanently once
+-- companionXp first reaches its `xp` (a running total, not a delta - the
+-- same shape titles.lua's own ladder uses): the companion is renamed and its
+-- hp/attack/defense grow by that entry's own flat amount, on top of
+-- whatever an earlier stage already added rather than replacing it. A
+-- hearth sprite's `heal` entries stack the same way into companionHealBonus,
+-- read by tendPlayer below alongside the species' own static heal rate.
+Companions.species = {
+  { key = "hound",  glyph = "d", name = "hunting hound", hp = 14, attack = 4, defense = 0, speed = 130, sight = 7,
+    evolutions = {
+      { level = 2, xp = 12, name = "warhound",   hp = 6,  attack = 2, defense = 1 },
+      { level = 3, xp = 40, name = "dire hound", hp = 10, attack = 3, defense = 1 },
+    } },
+  { key = "golem",  glyph = "G", name = "clay golem",    hp = 26, attack = 5, defense = 3, speed = 70,  sight = 5,
+    evolutions = {
+      { level = 2, xp = 15, name = "stone golem", hp = 10, attack = 2, defense = 2 },
+      { level = 3, xp = 45, name = "iron golem",  hp = 16, attack = 3, defense = 3 },
+    } },
+  { key = "sprite", glyph = "e", name = "hearth sprite", hp = 8,  attack = 1, defense = 0, speed = 110, sight = 8, heal = 2,
+    evolutions = {
+      { level = 2, xp = 10, name = "kindled sprite", hp = 4, attack = 1, defense = 0, heal = 1 },
+      { level = 3, xp = 35, name = "radiant sprite", hp = 6, attack = 1, defense = 1, heal = 2 },
+    } },
+}
+
+Companions.byKey = {}
+Companions.order = {}
+for _, spec in ipairs(Companions.species) do
+  Companions.byKey[spec.key] = spec
+  Companions.order[#Companions.order + 1] = spec.key
+end
+
+local ADJACENT = { { 1, 0 }, { -1, 0 }, { 0, 1 }, { 0, -1 }, { 1, 1 }, { 1, -1 }, { -1, 1 }, { -1, -1 } }
+
+-- Bonds a fresh companion of `key` onto a free cell next to the player,
+-- retiring any earlier bond first. Returns the new companion, or nil if
+-- every cell around the player is blocked.
+function Companions.summon(game, key)
+  local spec = Companions.byKey[key]
+  if not spec then return nil end
+  for _, other in ipairs(game.level.entities) do
+    if other.kind == "companion" and other:isAlive() then other.hp = 0 end
+  end
+  game:cleanupDead()
+  local player = game.player
+  for _, dir in ipairs(ADJACENT) do
+    local x, y = player.x + dir[1], player.y + dir[2]
+    if game.level.map:isWalkable(x, y) and not game.level:entityAt(x, y) then
+      local companion = Entity.new({
+        id = game:nextMonsterId(), x = x, y = y,
+        glyph = spec.glyph, name = spec.name, kind = "companion",
+        species = key, hp = spec.hp, attack = spec.attack, defense = spec.defense, speed = spec.speed,
+      })
+      companion.companionXp = 0
+      companion.companionLevel = 1
+      game.level.entities[#game.level.entities + 1] = companion
+      return companion
+    end
+  end
+  return nil
+end
+
+-- Chebyshev-1 (8-directional), matching mercenaries.lua's and reanimation.lua's
+-- own "adjacent" helpers exactly - both of those modules explicitly describe
+-- their combat branch as "the same three-branch shape as Companions.act", so
+-- this was meant to be one shared rule, not three independently-typed copies.
+-- This one alone used Manhattan-1 (4-directional) until now, so a companion
+-- caught diagonally next to a hostile monster fell through to
+-- stepMonsterToward instead of attacking - the exact same geometry a hireling
+-- or thrall standing in already engages without moving.
+local function adjacent(a, b)
+  return math.max(math.abs(a.x - b.x), math.abs(a.y - b.y)) == 1
+end
+
+-- Nearest living monster the companion can see within its species' sight
+-- radius, ties broken by ascending id for determinism. A blinded companion
+-- loses every longer-ranged sighting and falls back to melee range only,
+-- the same clamp Game:canSeePlayer applies to a blinded hostile monster.
+local function nearestHostile(game, companion)
+  local spec = Companions.byKey[companion.species]
+  local sight = spec.sight
+  if Status.has(companion, Status.BLIND) then sight = math.min(sight, 1) end
+  local best, bestDist = nil, math.huge
+  for _, entity in ipairs(game.level.entities) do
+    if entity.kind == "monster" and entity:isAlive() then
+      local dist = math.max(math.abs(entity.x - companion.x), math.abs(entity.y - companion.y))
+      if dist <= sight and Los.clear(game.level.map, companion.x, companion.y, entity.x, entity.y) then
+        if dist < bestDist or (dist == bestDist and entity.id < best.id) then
+          best, bestDist = entity, dist
+        end
+      end
+    end
+  end
+  return best
+end
+
+-- A hearth sprite mends its bonded player a little on any turn it does not
+-- spend fighting - the only companion with a passive off-turn effect. An
+-- evolved sprite's companionHealBonus (see Companions.gainXp) tops up its
+-- species' own static rate rather than replacing it.
+local function tendPlayer(game, companion)
+  local spec = Companions.byKey[companion.species]
+  if spec.heal and game.player.hp < game.player.maxHp then
+    local amount = spec.heal + (companion.companionHealBonus or 0)
+    game.player.hp = math.min(game.player.maxHp, game.player.hp + amount)
+  end
+end
+
+-- Credits a companion's own kill tally with `amount` xp and, in the same
+-- call, permanently applies every evolution stage (see Companions.species)
+-- its running companionXp total first reaches - possibly more than one at
+-- once, if a single grant vaults it clean past an intermediate threshold.
+-- Entirely separate from the xp Game:awardKill still credits the player for
+-- that identical kill (see Companions.act): the player's own level and this
+-- companion's are two independent ladders climbed off the same battles.
+function Companions.gainXp(game, companion, amount)
+  if not amount or amount <= 0 then return end
+  companion.companionXp = (companion.companionXp or 0) + amount
+  companion.companionLevel = companion.companionLevel or 1
+  local spec = Companions.byKey[companion.species]
+  if not spec or not spec.evolutions then return end
+  for _, stage in ipairs(spec.evolutions) do
+    if companion.companionLevel < stage.level and companion.companionXp >= stage.xp then
+      companion.companionLevel = stage.level
+      companion.name = stage.name
+      companion.maxHp = companion.maxHp + stage.hp
+      companion.hp = companion.hp + stage.hp
+      companion.attack = companion.attack + stage.attack
+      companion.defense = companion.defense + stage.defense
+      if stage.heal then
+        companion.companionHealBonus = (companion.companionHealBonus or 0) + stage.heal
+      end
+      game.log:add("your " .. companion.name .. " evolves, growing stronger")
+    end
+  end
+end
+
+-- The companion's full turn: engage the nearest visible monster if one is in
+-- reach, close the distance to one it can see but not yet reach, otherwise
+-- stay within a step of the player.
+function Companions.act(game, companion)
+  if game:allyActsConfused(companion) then return end
+  local target = nearestHostile(game, companion)
+  if target and adjacent(companion, target) then
+    local outcome = Combat.attack(companion, target)
+    game.log:add(string.format("your %s hits %s for %d", companion.name, target.name, outcome.damage))
+    game:emitNoise(companion.x, companion.y, Noise.MELEE)
+    if outcome.killed then
+      game:awardKill(target)
+      Companions.gainXp(game, companion, Monsters.xpFor(target))
+    end
+    return
+  end
+  if target then
+    game:stepMonsterToward(companion, target.x, target.y)
+    return
+  end
+  tendPlayer(game, companion)
+  if not adjacent(companion, game.player) and not (companion.x == game.player.x and companion.y == game.player.y) then
+    game:stepMonsterToward(companion, game.player.x, game.player.y)
+  end
+end
+
+return Companions

src/compendium.lua

@@ -0,0 +1,93 @@
+-- Cross-run bestiary: which species the player has ever laid eyes on, and how
+-- many of each they have slain. A compendium lives inside meta.lua's
+-- persistent save (see game.lua's Game.new, which reuses options.meta's own
+-- table by reference so every sighting and kill recorded mid-run is already
+-- sitting in the very table warren.lua writes back out with Meta.save) so it
+-- survives death exactly like renown and perks; a run started without
+-- --meta still gets a fresh, un-persisted one so every code path exercises
+-- the same bookkeeping either way.
+
+local Monsters = require("monsters")
+local Bosses = require("bosses")
+
+local Compendium = {}
+
+-- One evocative line per species, keyed the same as monsters.lua's species
+-- key or, for a boss, its bosses.lua catalog key (without the "boss_"
+-- prefix game.lua stamps onto the actual entity's `species` field).
+Compendium.FLAVOR = {
+  rat = "Bold enough to bite an ankle, never bold enough to fight fair.",
+  bat = "Flits erratically through the dark on a course only it can hear.",
+  kobold = "Travels in twos and threes; alone it barely has the nerve to bite.",
+  goblin = "Quick with a rusty blade, quicker to run once its pack scatters.",
+  archer = "A skeleton archer, more patient dead than most men are living.",
+  orc = "Broad-shouldered muscle with no plan beyond the next swing.",
+  wretch = "Something that used to be a person, now just hungry and afraid.",
+  troll = "Wounds close almost as fast as they open; fire is the only argument it respects.",
+  mage = "A dark mage who traded caution for whatever is behind that door.",
+  dragon = "Young enough to still be reckless, old enough to already breathe fire.",
+  zombie = "Shambles forward on rot and spite alone.",
+  slime = "Splits when struck; killing one carelessly just makes two problems.",
+  footpad = "Light-fingered and lighter on its feet - it wants your purse, not a fight.",
+  shaman = "Chants curses from a safe distance and flees the moment that fails.",
+  necromancer = "Would rather raise a friend from your kills than make one of its own.",
+  cleric = "Keeps its allies standing longer than they have any right to.",
+  chieftain = "Rallies its kin with a bellow that carries through the whole floor.",
+  shopkeeper = "Minds its own business and its stock, right up until you take both.",
+  warlord = "The Orc Warlord, whose rage only sharpens the longer a fight runs.",
+  lich = "The Lich, a will that outlasted its own body decades ago.",
+  bonequeen = "The Bone Queen, who never lacks for company - the dead keep answering her call.",
+}
+
+function Compendium.new()
+  return { seen = {}, kills = {} }
+end
+
+-- Marks `speciesKey` as sighted. Returns true only the first time it is ever
+-- seen, so a caller can choose whether to make anything of that moment; a
+-- repeat sighting is silently a no-op.
+function Compendium.noteSighting(compendium, speciesKey)
+  if not speciesKey or compendium.seen[speciesKey] then return false end
+  compendium.seen[speciesKey] = true
+  return true
+end
+
+function Compendium.noteKill(compendium, speciesKey)
+  if not speciesKey then return end
+  compendium.kills[speciesKey] = (compendium.kills[speciesKey] or 0) + 1
+end
+
+function Compendium.killCount(compendium, speciesKey)
+  return compendium.kills[speciesKey] or 0
+end
+
+function Compendium.hasSeen(compendium, speciesKey)
+  return compendium.seen[speciesKey] == true
+end
+
+-- Every species named in the wild bestiary or the boss catalog, in a fixed
+-- order (wild species first, then bosses), each row carrying its catalogued
+-- name, flavor line and this compendium's own seen/kill tally. `key` here
+-- matches exactly what an actual entity's `species` field would hold, so a
+-- caller can cross-reference the two without re-deriving the "boss_" prefix.
+function Compendium.entries(compendium)
+  local rows = {}
+  for _, spec in ipairs(Monsters.species) do
+    rows[#rows + 1] = {
+      key = spec.key, name = spec.name, flavor = Compendium.FLAVOR[spec.key],
+      seen = Compendium.hasSeen(compendium, spec.key),
+      kills = Compendium.killCount(compendium, spec.key),
+    }
+  end
+  for _, spec in ipairs(Bosses.catalog) do
+    local key = "boss_" .. spec.key
+    rows[#rows + 1] = {
+      key = key, name = spec.name, flavor = Compendium.FLAVOR[spec.key],
+      seen = Compendium.hasSeen(compendium, key),
+      kills = Compendium.killCount(compendium, key),
+    }
+  end
+  return rows
+end
+
+return Compendium

src/conductivity.lua

@@ -0,0 +1,80 @@
+-- Elemental terrain interaction between open water and the fire/lightning
+-- damage types resistances.lua already defines. Stepping into water leaves an
+-- entity soaked for a few turns after it moves on, not just on the exact
+-- water tile - the lingering dampness other systems read through Conductivity
+-- rather than re-checking the tile underfoot themselves. A soaked entity
+-- resists catching fire outright (Status.apply refuses a BURNING application,
+-- the same way a water tile already douses tile fire in Hazards.step) and,
+-- for damage that already lands, dampens further fire (Conductivity.applyFire,
+-- used by hazards.lua's fire tick and status.lua's own BURNING dot) while
+-- conducting lightning for a bonus (Conductivity.applyLightning, used by
+-- spells.lua's shock bolt) - the water clinging to them is exactly what makes
+-- a live wire so much worse to be standing in. This is scoped to fire/
+-- lightning that already routes through here; an instantaneous hit like
+-- lava contact or a breath attack that computes its own damage inline is
+-- left alone - only ignition-prevention (resistsIgnition) reaches those.
+--
+-- LIGHTNING was previously a fully declared Resistances type with nothing in
+-- the game that ever dealt it - elites could roll a resist tier for a damage
+-- type nothing ever used. Conductivity.applyLightning plus spells.lua's new
+-- shock bolt spell are what makes an elite's rolled lightning resistance
+-- (see elites.lua) matter for the first time.
+
+local Tiles = require("tiles")
+local Resistances = require("resistances")
+
+local Conductivity = {}
+
+Conductivity.SOAK_DURATION = 3
+Conductivity.LIGHTNING_BONUS_PERCENT = 50
+Conductivity.FIRE_DAMPEN_PERCENT = 50
+
+function Conductivity.isWet(entity)
+  return (entity.wet or 0) > 0
+end
+
+-- Refreshes `entity`'s soak counter to the full duration when it ends its
+-- turn standing on open water, or counts it down by one otherwise - the same
+-- "renew on cause, decay on absence" shape a stacked status.lua effect's own
+-- duration follows, but tracked as a plain entity field since it is a terrain
+-- reaction rather than something any status.lua effect key describes.
+function Conductivity.tick(level, entity)
+  if level.map:get(entity.x, entity.y) == Tiles.WATER then
+    entity.wet = Conductivity.SOAK_DURATION
+  elseif (entity.wet or 0) > 0 then
+    entity.wet = entity.wet - 1
+  end
+end
+
+-- Fire damage against a soaked target is dampened on top of whatever
+-- Resistances.tierOf already resolves - drenched cloth or hide smoulders
+-- rather than catching properly. Immune still floors it at zero.
+function Conductivity.applyFire(entity, amount)
+  local dealt = Resistances.apply(entity, amount, Resistances.FIRE)
+  if dealt > 0 and Conductivity.isWet(entity) then
+    dealt = math.max(1, dealt - (dealt * Conductivity.FIRE_DAMPEN_PERCENT) // 100)
+  end
+  return dealt
+end
+
+-- Lightning damage against a soaked target conducts through the water
+-- clinging to them for a bonus on top of whatever Resistances.tierOf already
+-- resolves - immune still blocks it outright, same as any other type.
+function Conductivity.applyLightning(entity, amount)
+  local dealt = Resistances.apply(entity, amount, Resistances.LIGHTNING)
+  if dealt > 0 and Conductivity.isWet(entity) then
+    dealt = dealt + (dealt * Conductivity.LIGHTNING_BONUS_PERCENT) // 100
+  end
+  return dealt
+end
+
+-- A soaked target's own dampness snuffs any attempt to set them alight
+-- outright, before the BURNING effect is ever recorded (see status.lua's
+-- Status.apply) - the same protection a water tile already gives tile fire
+-- in Hazards.step, extended to an entity that carries its own wetness onto
+-- dry ground.
+function Conductivity.resistsIgnition(entity)
+  return Conductivity.isWet(entity)
+end
+
+return Conductivity

src/corpses.lua

@@ -0,0 +1,103 @@
+-- Raw meat left behind by a fallen wild monster - a second, turn-costed food
+-- source alongside a found or bought ration (see Items.food, shop.lua). A
+-- corpse decays over a fixed number of rounds whether or not the player is
+-- even on this floor to see it (Corpses.step runs off Game:endPlayerTurn
+-- exactly like hazards.lua's fire/gas and nodes.lua's vein cooldown); left
+-- alone past its rot threshold it still butchers in one stroke, but the
+-- reward turns from a meal into a bout of poisoning instead. Undead crumble
+-- to dust and leave nothing to carve (see factions.lua's UNDEAD tag), a mimic
+-- was never alive to begin with (mimics.lua), and a boss's fixed loot drop
+-- (bosses.lua) is reward enough on its own - none of the three spawn a
+-- corpse. Corpses are plain data on level.corpses, exactly like
+-- level.hazards and level.nodes, so they serialize with no special
+-- save-format handling.
+
+local Factions = require("factions")
+local Items = require("items")
+local Status = require("status")
+
+local Corpses = {}
+
+Corpses.DECAY_TURNS = 60
+Corpses.ROT_TURNS = 25
+
+Corpses.NUTRITION_MIN = 30
+Corpses.NUTRITION_MAX = 200
+Corpses.NUTRITION_PER_HP = 8
+
+-- Wild monster corpses only: the undead were already dead before the player
+-- got there, a mimic's "corpse" would just be its loot disguise falling
+-- apart, and a boss's own scripted drop already covers its reward.
+function Corpses.leavesCorpse(target)
+  return target.faction ~= Factions.UNDEAD and not target.mimic and not target.isBoss
+end
+
+-- Nutrition scales with how tough the felled species was (maxHp, itself
+-- depth-scaled per monsters.lua), clamped to a fixed band so a late-game
+-- dragon corpse never trivializes hunger outright.
+local function nutritionFor(maxHp)
+  local raw = maxHp * Corpses.NUTRITION_PER_HP
+  return math.max(Corpses.NUTRITION_MIN, math.min(Corpses.NUTRITION_MAX, raw))
+end
+
+function Corpses.new(target)
+  return {
+    x = target.x, y = target.y,
+    species = target.species, name = target.name,
+    nutrition = nutritionFor(target.maxHp),
+    decay = Corpses.DECAY_TURNS,
+  }
+end
+
+-- Appends a fresh corpse for `target` onto `level.corpses`, or does nothing
+-- for anything Corpses.leavesCorpse rules out.
+function Corpses.spawn(level, target)
+  if not Corpses.leavesCorpse(target) then return end
+  level.corpses[#level.corpses + 1] = Corpses.new(target)
+end
+
+function Corpses.isRotten(corpse)
+  return corpse.decay <= Corpses.ROT_TURNS
+end
+
+-- Advances every corpse on the level one round toward fully rotting away,
+-- exactly like hazards.step and nodes.step - called once per round, not per
+-- actor, so a seeded run always loses a given corpse on the identical turn
+-- regardless of how many actors acted that round.
+function Corpses.step(level)
+  for i = #level.corpses, 1, -1 do
+    local corpse = level.corpses[i]
+    corpse.decay = corpse.decay - 1
+    if corpse.decay <= 0 then table.remove(level.corpses, i) end
+  end
+end
+
+-- Drops `corpse` off level.corpses outright - shared by every way of
+-- spending one (see Corpses.butcher below and scavenging.lua's own harvest),
+-- so a corpse can never be carved twice over.
+function Corpses.remove(level, corpse)
+  for i, candidate in ipairs(level.corpses) do
+    if candidate == corpse then
+      table.remove(level.corpses, i)
+      return
+    end
+  end
+end
+
+-- Carves up `corpse` in one stroke, always spending it whether the meat is
+-- still good or not. A corpse still inside its rot threshold yields a fresh
+-- Items.food ration into the player's inventory, eaten later exactly like a
+-- found one; a corpse butchered past that threshold instead poisons the
+-- player outright - the corpse itself is just as gone either way.
+function Corpses.butcher(game, corpse)
+  Corpses.remove(game.level, corpse)
+  if Corpses.isRotten(corpse) then
+    Status.apply(game.player, Status.POISON, 5, 2)
+    return string.format("the %s corpse has rotted; you gag it down and immediately regret it", corpse.name)
+  end
+  local food = Items.food(corpse.name .. " meat", corpse.nutrition)
+  game.player.inventory[#game.player.inventory + 1] = food
+  return string.format("you carve %d nutrition worth of meat from the %s corpse", corpse.nutrition, corpse.name)
+end
+
+return Corpses

src/crafting.lua

@@ -0,0 +1,181 @@
+-- Deterministic gear crafting, layered on top of the loot-rolled affix
+-- system (affixes.lua). Killing monsters earns essence; essence forges tier-1
+-- gems; two matching gems merge into one gem a tier higher; a gem sockets
+-- into gear for a guaranteed on-hit rider alongside a flat power bump;
+-- tempering spends essence directly for power at rising cost; disenchanting
+-- strips a rolled affix back into essence. Nothing here rolls dice - a build
+-- is entirely a function of the essence spent on it, distinct from the luck
+-- of what affixes.lua hands out on drops.
+
+local Items = require("items")
+local Status = require("status")
+local Affixes = require("affixes")
+
+local Crafting = {}
+
+Crafting.FIRE = "fire"
+Crafting.FROST = "frost"
+Crafting.SHOCK = "shock"
+Crafting.VENOM = "venom"
+
+Crafting.elements = { Crafting.FIRE, Crafting.FROST, Crafting.SHOCK, Crafting.VENOM }
+
+-- SHOCK's duration is 2, not 1: Status.tick decrements duration before
+-- skipsTurn is ever checked (see status.lua), and a hit landed during the
+-- player's own turn ticks the victim's status for the first time on that
+-- SAME round, in the victim's own upcoming takeMonsterTurn - a duration-1
+-- stun would already read 0 and be gone before skipsTurn ever saw it,
+-- silently never stunning anything. 2 survives that first tick with 1 left,
+-- which is exactly enough to skip the one turn immediately after the hit.
+Crafting.riders = {
+  [Crafting.FIRE]  = { status = Status.BURNING, duration = 3, potency = 2 },
+  [Crafting.FROST] = { status = Status.SLOW,    duration = 2, potency = 1 },
+  [Crafting.SHOCK] = { status = Status.STUN,    duration = 2, potency = 1 },
+  [Crafting.VENOM] = { status = Status.POISON,  duration = 4, potency = 2 },
+}
+
+Crafting.tierNames = { "chip", "flawed", "perfect" }
+Crafting.MAX_TIER = #Crafting.tierNames
+
+Crafting.FORGE_COST = 6
+Crafting.ENCHANT_COST = 10
+Crafting.TEMPER_MAX = 5
+
+local function isElement(element)
+  return Crafting.riders[element] ~= nil
+end
+
+function Crafting.gem(element, tier)
+  return {
+    kind = Items.GEM,
+    glyph = "*",
+    element = element,
+    tier = tier,
+    power = tier,
+    name = Crafting.tierNames[tier] .. " " .. element .. " gem",
+  }
+end
+
+-- A kill's essence scales with the monster's own xp reward, so the crafting
+-- economy tracks the game's existing difficulty curve instead of needing a
+-- second balance table.
+function Crafting.essenceFor(xp)
+  return math.max(1, xp // 3)
+end
+
+-- Spends essence to forge a fresh tier-1 gem of the given element.
+function Crafting.forge(entity, element)
+  if not isElement(element) then return false, "no such element" end
+  if entity.essence < Crafting.FORGE_COST then return false, "not enough essence" end
+  entity.essence = entity.essence - Crafting.FORGE_COST
+  return true, Crafting.gem(element, 1)
+end
+
+-- Combines two gems of the same element and tier into one gem a tier higher.
+-- Mismatched pairs are rejected untouched, so a misclick costs nothing.
+function Crafting.mergeGems(gemA, gemB)
+  if gemA.element ~= gemB.element then return false, "elements do not match" end
+  if gemA.tier ~= gemB.tier then return false, "tiers do not match" end
+  if gemA.tier >= Crafting.MAX_TIER then return false, "already at maximum tier" end
+  return true, nil, Crafting.gem(gemA.element, gemA.tier + 1)
+end
+
+local function socketable(item)
+  return item.kind == Items.WEAPON or item.kind == Items.ARMOR
+    or item.kind == Items.BOW or item.kind == Items.RING
+end
+
+-- weapon/armor bake their equipped power straight into attack/defense
+-- (see items.equipWeapon/equipArmor), so any crafting action that edits
+-- item.power after the fact must apply the same delta to the wielder to
+-- avoid a stat that only updates on the next re-equip.
+local function applyPowerDelta(entity, item, delta)
+  if delta == 0 then return end
+  if entity.weapon == item then
+    entity.attack = entity.attack + delta
+  elseif entity.armor == item then
+    entity.defense = entity.defense + delta
+  end
+end
+
+-- Attaches a gem's rider and power to a piece of gear, replacing whatever was
+-- socketed before - the old gem is pried loose and breaks, it is not
+-- returned. Rings and bows take the rider (for ranged/aura play) but only
+-- weapon and armor power feeds attack/defense; see socketPowerKind below.
+function Crafting.socket(entity, item, gem)
+  if not socketable(item) then return false, "cannot be socketed" end
+  if gem.kind ~= Items.GEM then return false, "not a gem" end
+  local previousPower = item.socket and item.socket.power or 0
+  item.socket = { element = gem.element, tier = gem.tier, power = gem.power, onHit = Crafting.riders[gem.element] }
+  if item.kind == Items.WEAPON or item.kind == Items.ARMOR then
+    local delta = gem.power - previousPower
+    item.power = item.power + delta
+    applyPowerDelta(entity, item, delta)
+  end
+  return true
+end
+
+function Crafting.temperCost(item)
+  return ((item.temper or 0) + 1) * 4
+end
+
+-- Flat, permanent power increase capped so tempering cannot out-scale simply
+-- finding better gear; each step costs more essence than the last.
+function Crafting.temper(entity, item)
+  if item.kind ~= Items.WEAPON and item.kind ~= Items.ARMOR then
+    return false, "cannot be tempered"
+  end
+  local level = item.temper or 0
+  if level >= Crafting.TEMPER_MAX then return false, "fully tempered" end
+  local cost = Crafting.temperCost(item)
+  if entity.essence < cost then return false, "not enough essence" end
+  entity.essence = entity.essence - cost
+  item.temper = level + 1
+  item.power = item.power + 1
+  applyPowerDelta(entity, item, 1)
+  return true
+end
+
+local function affixPool(item)
+  if item.kind == Items.WEAPON then return Affixes.weapon end
+  if item.kind == Items.ARMOR then return Affixes.armor end
+  return nil
+end
+
+-- Grants a guaranteed, chosen affix to gear that has none - the deterministic
+-- counterpart to affixes.rollWeapon/rollArmor rolling one by chance on drop.
+function Crafting.enchant(entity, item, affixKey)
+  local pool = affixPool(item)
+  if not pool then return false, "cannot be enchanted" end
+  if item.affix then return false, "already bears an affix" end
+  local chosen
+  for _, entry in ipairs(pool) do
+    if entry.key == affixKey then chosen = entry end
+  end
+  if not chosen then return false, "unknown affix" end
+  if entity.essence < Crafting.ENCHANT_COST then return false, "not enough essence" end
+  entity.essence = entity.essence - Crafting.ENCHANT_COST
+  Affixes.decorate(item, chosen)
+  applyPowerDelta(entity, item, chosen.power)
+  return true
+end
+
+-- Strips a rolled affix back into essence, worth more the stronger the affix
+-- was, undoing affixes.decorate's power bump and name prefix exactly.
+function Crafting.disenchant(entity, item)
+  if not item.affix then return false, "nothing to disenchant" end
+  local affix = item.affix
+  local refund = Crafting.FORGE_COST + affix.power * 3
+  applyPowerDelta(entity, item, -affix.power)
+  item.power = item.power - affix.power
+  local prefix = affix.name .. " "
+  if item.name:sub(1, #prefix) == prefix then
+    item.name = item.name:sub(#prefix + 1)
+  end
+  item.affix = nil
+  item.damageType = nil
+  entity.essence = entity.essence + refund
+  return true, refund
+end
+
+return Crafting

src/curses.lua

@@ -0,0 +1,161 @@
+-- Malevolent gear rolled as the dark mirror of affixes.lua's beneficial
+-- prefixes. A cursed weapon, suit of armor, bow or ring looks completely
+-- ordinary on the ground and in the pack - its stat penalty is already
+-- folded into item.power/item.range at generation time, so nothing
+-- downstream needs to know an item is cursed to use its numbers correctly.
+-- Putting one on binds it in place: trying to swap it out for something
+-- else fails and reveals the curse right there, the same "you find out by
+-- trying" moment as a classic roguelike's stuck cursed ring. This is a
+-- different curse from shrines.lua's: that one is a temporary status
+-- inflicted the instant a prayer backfires, this one travels with a
+-- specific item and needs a specific remedy - a scroll of remove curse, or
+-- a prayer at a shrine of fortune - to lift.
+
+local Curses = {}
+
+Curses.WEAKNESS = "weakness"
+Curses.BRITTLE = "brittle"
+Curses.FAULTY = "faulty"
+Curses.AFFLICTION = "affliction"
+
+-- The four wearable slots a curse can ever occupy, in a fixed order so
+-- "the earliest cursed slot" always means the same thing across callers.
+Curses.SLOTS = { "weapon", "armor", "ring", "bow" }
+
+Curses.pool = {
+  weapon = { { key = Curses.WEAKNESS, powerPenalty = 2 } },
+  armor = { { key = Curses.BRITTLE, powerPenalty = 2 } },
+  bow = { { key = Curses.FAULTY, powerPenalty = 1, rangePenalty = 2 } },
+  ring = { { key = Curses.AFFLICTION, drain = 1 } },
+}
+
+Curses.CHANCE_NUMERATOR = 1
+Curses.CHANCE_DENOMINATOR = 8
+
+-- Rolls a curse for a freshly generated `slot` item, or nil most of the
+-- time. Weapons and armor should only ever be offered here when they did
+-- not already land a beneficial affix (see builder.lua's rollItem), so a
+-- single drop is never simultaneously a blessing and a curse.
+function Curses.roll(rng, slot)
+  local pool = Curses.pool[slot]
+  if not pool then return nil end
+  if not rng:chance(Curses.CHANCE_NUMERATOR, Curses.CHANCE_DENOMINATOR) then return nil end
+  return pool[rng:range(1, #pool)]
+end
+
+-- Binds `curse` onto `item`, silently folding its stat penalty into the
+-- item's own numbers. The curse itself stays hidden (curseRevealed false)
+-- until reveal() is called by a discovery path.
+function Curses.afflict(item, curse)
+  item.cursed = true
+  item.curseKind = curse.key
+  item.curseRevealed = false
+  if curse.powerPenalty then
+    item.cursePenalty = curse.powerPenalty
+    item.power = math.max(0, item.power - curse.powerPenalty)
+  end
+  if curse.rangePenalty then
+    item.curseRangePenalty = curse.rangePenalty
+    item.range = math.max(1, item.range - curse.rangePenalty)
+  end
+  if curse.drain then
+    item.curseDrain = curse.drain
+  end
+  return item
+end
+
+function Curses.isCursed(item)
+  return item ~= nil and item.cursed == true
+end
+
+function Curses.isRevealed(item)
+  return item ~= nil and item.curseRevealed == true
+end
+
+function Curses.reveal(item)
+  if item then item.curseRevealed = true end
+end
+
+-- True once whatever `entity` currently has worn in `slot` is cursed.
+function Curses.isBoundIn(entity, slot)
+  return Curses.isCursed(entity[slot])
+end
+
+-- Refuses to let go of a bound item: reveals the curse the instant the
+-- wearer discovers it - the whole point of the mechanic is finding out by
+-- trying - and reports false so the caller can leave the replacement
+-- sitting in the pack instead of swapping it in. An empty or clean slot
+-- always succeeds without side effects.
+function Curses.tryRelease(entity, slot)
+  local item = entity[slot]
+  if not Curses.isCursed(item) then return true end
+  Curses.reveal(item)
+  return false
+end
+
+-- Undoes `item`'s curse in place: restores whatever power/range it cost,
+-- drops the drain, and clears every curse field so the piece swaps out
+-- normally from here on. No-op (returns false) on clean or absent gear.
+function Curses.cleanse(item)
+  if not Curses.isCursed(item) then return false end
+  if item.cursePenalty then
+    item.power = item.power + item.cursePenalty
+    item.cursePenalty = nil
+  end
+  if item.curseRangePenalty then
+    item.range = item.range + item.curseRangePenalty
+    item.curseRangePenalty = nil
+  end
+  item.curseDrain = nil
+  item.cursed = nil
+  item.curseKind = nil
+  item.curseRevealed = nil
+  return true
+end
+
+-- Lifts every curse currently worn by `entity` across all four slots,
+-- returning how many pieces were cleansed - 0 when none of its gear was
+-- cursed to begin with, so callers can report "nothing to cleanse".
+function Curses.cleanseWorn(entity)
+  local count = 0
+  for _, slot in ipairs(Curses.SLOTS) do
+    if Curses.cleanse(entity[slot]) then count = count + 1 end
+  end
+  return count
+end
+
+-- Reveals the first still-hidden curse among `entity`'s worn gear, in
+-- Curses.SLOTS order, and returns the item it found - or nil once nothing
+-- worn is hiding a curse anymore.
+function Curses.revealFirstUnknown(entity)
+  for _, slot in ipairs(Curses.SLOTS) do
+    local item = entity[slot]
+    if Curses.isCursed(item) and not Curses.isRevealed(item) then
+      Curses.reveal(item)
+      return item
+    end
+  end
+  return nil
+end
+
+-- The hit points a cursed ring bleeds from its wearer this round. Only a
+-- ring's affliction drains on a timer - weapon, armor and bow curses are a
+-- flat, one-time stat tax instead - so this is the only per-turn cost the
+-- whole system has.
+function Curses.drainAmount(entity)
+  local ring = entity.ring
+  if ring and ring.curseDrain then return ring.curseDrain end
+  return 0
+end
+
+-- Display name for `item`: an unrevealed curse hides behind the item's
+-- ordinary name exactly like a clean piece, a revealed one is prefixed so
+-- the player never again mistakes it for something safe to swap out.
+function Curses.label(item, name)
+  if Curses.isCursed(item) and Curses.isRevealed(item) then
+    return "cursed " .. name
+  end
+  return name
+end
+
+return Curses

src/digging.lua

@@ -0,0 +1,113 @@
+-- Tunneling through plain rock, player-driven with a limited-use pick and
+-- monster-driven for a burrower born to it (see monsters.lua's "burrower"
+-- species and ai.lua's "tunnel" behaviour). A dug wall never clears in one
+-- swing: it crumbles to Tiles.RUBBLE first - already walkable and already
+-- open to sight, unlike the wall it replaced - and only a second swing
+-- against that same cell clears it the rest of the way to open floor, so a
+-- tunnel always costs two hits, never one, whoever is swinging. A vault's
+-- own boundary (Tiles.VAULT_DOOR) never yields no matter how many swings it
+-- takes - only the lever it guards opens it (see Game:pullLever). Every
+-- swing risks a cave-in that buries the digger for damage instead of
+-- yielding progress, and a lucky one strikes a raw vein outright - clearing
+-- the wall in a single stroke and paying out essence exactly like a spent
+-- nodes.lua vein, but only for a digger that tracks essence at all (the
+-- player; a no-op reward for anything else, i.e. a monster).
+-- Digging mutates the map tile grid directly, exactly like terrain.lua's
+-- hazards bake straight into it, so a dug tunnel needs no special
+-- save-format handling of its own - the map already serializes.
+
+local Tiles = require("tiles")
+
+local Digging = {}
+
+Digging.CAVE_IN_CHANCE_DEN = 8
+Digging.CAVE_IN_DAMAGE_MIN = 2
+Digging.CAVE_IN_DAMAGE_MAX = 5
+Digging.ORE_STRIKE_CHANCE_DEN = 10
+Digging.ORE_ESSENCE_MIN = 4
+Digging.ORE_ESSENCE_MAX = 9
+Digging.DEFAULT_USES = 20
+
+-- A burrower senses the player's direction straight through solid rock out
+-- to this many Chebyshev cells - beyond it, it idles exactly like "flee"
+-- idles once it loses sight, rather than clawing forever from across the map.
+Digging.SENSE_RANGE = 6
+
+-- Only a plain wall or the rubble left by a prior swing can be dug further;
+-- open floor has nothing left to carve and a vault door never yields.
+function Digging.canDig(map, x, y)
+  if not map:inBounds(x, y) then return false end
+  local tile = map:get(x, y)
+  return tile == Tiles.WALL or tile == Tiles.RUBBLE
+end
+
+-- Resolves one swing of `digger`'s pick (or a burrower's own claws) against
+-- (x, y), already known diggable by the caller. Mutates the map tile in
+-- place on progress, deals cave-in damage to the digger on bad luck, and
+-- always returns a log line describing what happened.
+function Digging.swing(game, digger, x, y)
+  local map = game.level.map
+  local tile = map:get(x, y)
+  local isPlayer = digger == game.player
+  if game.rng:chance(1, Digging.CAVE_IN_CHANCE_DEN) then
+    local dealt = game.rng:range(Digging.CAVE_IN_DAMAGE_MIN, Digging.CAVE_IN_DAMAGE_MAX)
+    digger.hp = digger.hp - dealt
+    if isPlayer then return string.format("the rock groans and buries you for %d", dealt) end
+    return string.format("the rock groans and buries %s for %d", digger.name, dealt)
+  end
+  if tile == Tiles.WALL then
+    if game.rng:chance(1, Digging.ORE_STRIKE_CHANCE_DEN) then
+      map:set(x, y, Tiles.FLOOR)
+      if digger.essence ~= nil then
+        local amount = game.rng:range(Digging.ORE_ESSENCE_MIN, Digging.ORE_ESSENCE_MAX)
+        digger.essence = digger.essence + amount
+        return string.format("you strike a vein and pocket %d essence", amount)
+      end
+      return string.format("%s claws straight through a vein of ore", digger.name)
+    end
+    map:set(x, y, Tiles.RUBBLE)
+    if isPlayer then return "you carve through the rock" end
+    return string.format("%s carves through the rock", digger.name)
+  end
+  map:set(x, y, Tiles.FLOOR)
+  if isPlayer then return "you clear the rubble away" end
+  return string.format("%s clears the rubble away", digger.name)
+end
+
+-- Consumes one use from `entity.pick`'s durability, discarding the tool
+-- once its edge dulls past use. A no-op (returns nil) for anything without
+-- a pick equipped - a burrower digs with its own claws instead, which never
+-- wear out. Returns a log line only on the swing that breaks the tool.
+function Digging.wearPick(entity)
+  local pick = entity.pick
+  if not pick then return nil end
+  pick.uses = pick.uses - 1
+  if pick.uses <= 0 then
+    entity.pick = nil
+    return "your " .. pick.name .. " crumbles apart from the strain"
+  end
+  return nil
+end
+
+-- Orthogonal step directions from (mx, my) toward (tx, ty), longer axis
+-- first, in the same 4-connected grid every monster already moves and
+-- paths on (see game.lua's MONSTER_DIRS, astar.lua's DIRS) - never a
+-- diagonal, so a dug tunnel is always walkable by the same step logic that
+-- carved it. Returns an empty list when already on the target cell.
+function Digging.directionsToward(mx, my, tx, ty)
+  local ddx = tx - mx
+  local ddy = ty - my
+  local dx = ddx > 0 and 1 or (ddx < 0 and -1 or 0)
+  local dy = ddy > 0 and 1 or (ddy < 0 and -1 or 0)
+  local dirs = {}
+  if math.abs(ddx) >= math.abs(ddy) then
+    if dx ~= 0 then dirs[#dirs + 1] = { dx, 0 } end
+    if dy ~= 0 then dirs[#dirs + 1] = { 0, dy } end
+  else
+    if dy ~= 0 then dirs[#dirs + 1] = { 0, dy } end
+    if dx ~= 0 then dirs[#dirs + 1] = { dx, 0 } end
+  end
+  return dirs
+end
+
+return Digging

src/disarm.lua

@@ -0,0 +1,82 @@
+-- Passive trap sense and the deliberate act of disarming what it finds.
+-- Every trap already carries a hidden/revealed pair (level.traps entries -
+-- see level.lua and game.lua's Game:springTrap, which flips a trap's
+-- `revealed` the instant it is triggered, whether by a footstep or a failed
+-- disarm below). This module adds a third state in between the two,
+-- `detected`: noticed but not yet sprung. Detection is a passive roll
+-- against every still-hidden trap within a step of the player, rolled once
+-- per player turn from Game:endPlayerTurn - once per round rather than once
+-- per actor, exactly like hazards.step and events.step already advance the
+-- world. Disarming a detected trap is the deliberate, risky counterpart:
+-- succeed and it is gone for good, plus a handful of essence for the
+-- salvaged parts; fail and it springs on the disarmer exactly as if they
+-- had blundered onto it outright, through the very same Game:springTrap
+-- every other trigger already shares.
+
+local Disarm = {}
+
+Disarm.DETECT_NUMERATOR = 1
+Disarm.DETECT_DENOMINATOR = 4
+
+Disarm.DISARM_BASE_NUMERATOR = 3
+Disarm.DISARM_BASE_DENOMINATOR = 5
+Disarm.LEVEL_BONUS_DIVISOR = 4
+
+Disarm.SALVAGE_MIN = 3
+Disarm.SALVAGE_MAX = 6
+
+-- Sweeps every trap within Chebyshev distance 1 of (px, py) - the same
+-- adjacency a monster's melee reach and a shrine's own footprint are judged
+-- by elsewhere - that is neither already detected nor already sprung, and
+-- rolls each independently. Returns the traps newly detected this call (in
+-- level.traps order), so a caller can report exactly what was noticed.
+function Disarm.sweep(level, rng, px, py)
+  local found = {}
+  for _, trap in ipairs(level.traps) do
+    if not trap.detected and not trap.revealed
+      and math.max(math.abs(trap.x - px), math.abs(trap.y - py)) <= 1
+      and rng:chance(Disarm.DETECT_NUMERATOR, Disarm.DETECT_DENOMINATOR) then
+      trap.detected = true
+      found[#found + 1] = trap
+    end
+  end
+  return found
+end
+
+-- Odds of successfully disarming a detected trap: a flat base that climbs
+-- slightly with player level, capped a point shy of the denominator so
+-- disarming never becomes a sure thing no matter how experienced the
+-- player gets.
+function Disarm.oddsFor(player)
+  local numerator = Disarm.DISARM_BASE_NUMERATOR + player.level // Disarm.LEVEL_BONUS_DIVISOR
+  if numerator > Disarm.DISARM_BASE_DENOMINATOR - 1 then
+    numerator = Disarm.DISARM_BASE_DENOMINATOR - 1
+  end
+  return numerator, Disarm.DISARM_BASE_DENOMINATOR
+end
+
+-- Resolves one disarm attempt against `trap`, already known to `game`'s
+-- player (see Game:disarmTrap, which enforces that it was actually
+-- detected first). On success the trap is spliced out of level.traps for
+-- good and its salvage is credited as essence; on failure it springs on the
+-- player through Game:springTrap, the identical consequence a careless
+-- footstep would have caused. Returns (true, line) or (false, nil) - a
+-- failure logs nothing of its own since springTrap already does.
+function Disarm.attempt(game, trap)
+  local numerator, denominator = Disarm.oddsFor(game.player)
+  if not game.rng:chance(numerator, denominator) then
+    game:springTrap(trap, game.player)
+    return false, nil
+  end
+  for i, candidate in ipairs(game.level.traps) do
+    if candidate == trap then
+      table.remove(game.level.traps, i)
+      break
+    end
+  end
+  local salvage = game.rng:range(Disarm.SALVAGE_MIN, Disarm.SALVAGE_MAX)
+  game.player.essence = game.player.essence + salvage
+  return true, string.format("you carefully disarm the trap, salvaging %d essence", salvage)
+end
+
+return Disarm

src/disease.lua

@@ -0,0 +1,131 @@
+-- Progressive affliction caught from a carrier's bite, distinct from both
+-- status.lua's per-turn buffs/debuffs (a fixed potency for a fixed
+-- duration) and curses.lua's item-bound penalties (permanent until a
+-- specific remedy). A disease sits silently through its incubation with no
+-- outward sign at all, then erupts and starts dealing damage every turn,
+-- worsening to a harsher stage on a fixed clock if nothing cures it first.
+-- Its tick damage routes through resistances.lua exactly like poison's own
+-- damage-over-time (see status.lua's POISON tick), so a plague-resistant
+-- survivor shrugs off what would gut anyone else. A disease is plain data
+-- on entity.disease, so it serializes with no special handling; the carrier
+-- tag a species bite leaves on entity.biteDisease (see monsters.lua) is
+-- copied on exactly like breath or ability already are.
+
+local Resistances = require("resistances")
+
+local Disease = {}
+
+Disease.ROT = "rot"
+Disease.PLAGUE = "plague"
+Disease.PARASITES = "parasites"
+
+-- Fixed order so a given rng draw always names the same affliction.
+Disease.order = { Disease.ROT, Disease.PLAGUE, Disease.PARASITES }
+
+Disease.MAX_STAGE = 3
+
+Disease.defs = {
+  [Disease.ROT] = {
+    name = "wound rot", incubation = 4, stageTurns = 8,
+    stagePotency = { 2, 4, 7 },
+  },
+  [Disease.PLAGUE] = {
+    name = "black plague", incubation = 6, stageTurns = 6,
+    stagePotency = { 3, 6, 10 },
+  },
+  [Disease.PARASITES] = {
+    name = "gut parasites", incubation = 3, stageTurns = 10,
+    stagePotency = { 1, 3, 5 },
+  },
+}
+
+function Disease.isInfected(entity)
+  return entity.disease ~= nil
+end
+
+-- Whether the infection has finished incubating and is actively dealing
+-- damage each tick, as opposed to sitting silent and undetected.
+function Disease.hasErupted(entity)
+  return entity.disease ~= nil and entity.disease.stage > 0
+end
+
+-- Seeds a fresh infection of `key` on `entity`, refusing to pile a second
+-- affliction on top of one already incubating or erupted - the same
+-- one-at-a-time rule status.lua's own stacking already enforces for e.g.
+-- poison overwriting duration rather than compounding. Returns whether the
+-- infection actually took hold.
+function Disease.infect(entity, key)
+  if Disease.isInfected(entity) then return false end
+  local def = Disease.defs[key]
+  if not def then return false end
+  entity.disease = { key = key, incubation = def.incubation, stage = 0, sinceStage = 0 }
+  return true
+end
+
+-- Lifts whatever infection `entity` is carrying, incubating or already
+-- erupted alike. Returns false without state change when there was nothing
+-- to cure.
+function Disease.cure(entity)
+  if not Disease.isInfected(entity) then return false end
+  entity.disease = nil
+  return true
+end
+
+-- The stage's flat tick damage before resistance is applied, or 0 while
+-- still incubating (no outward symptom yet) or entirely uninfected.
+function Disease.stagePotency(entity)
+  local infection = entity.disease
+  if not infection or infection.stage == 0 then return 0 end
+  return Disease.defs[infection.key].stagePotency[infection.stage]
+end
+
+-- One tick per turn on the host's own clock: counts incubation down in
+-- silence, breaks out into stage one the moment it reaches zero, then
+-- deals that stage's potency each further tick and escalates to the next
+-- stage once it has lingered untreated for its full stageTurns window (the
+-- top stage simply keeps ticking rather than escalating further). Returns a
+-- log line for anything a player would actually notice - the eruption
+-- itself, an escalation, or a nonzero tick of damage - and nil for a turn
+-- that only ticked incubation down uneventfully.
+-- True only for the player, whose entity.name is the pronoun "you" - a
+-- subject that takes plain ("you break out", "you are wracked") verb forms
+-- in English rather than the third-person-singular ("breaks out", "is
+-- wracked") a named host like "orc" takes. Every message below branches on
+-- this exactly like Game:springTrap and Game:checkTerrainFor already branch
+-- on the same pronoun problem elsewhere in the engine.
+local function isPlayer(entity)
+  return entity.kind == "player"
+end
+
+function Disease.tick(entity)
+  local infection = entity.disease
+  if not infection then return nil end
+  local def = Disease.defs[infection.key]
+  if infection.stage == 0 then
+    infection.incubation = infection.incubation - 1
+    if infection.incubation <= 0 then
+      infection.stage = 1
+      infection.sinceStage = 0
+      return isPlayer(entity) and string.format("you break out in %s", def.name)
+        or string.format("%s breaks out in %s", entity.name, def.name)
+    end
+    return nil
+  end
+  local dealt = Resistances.apply(entity, def.stagePotency[infection.stage], Resistances.POISON)
+  entity.hp = entity.hp - dealt
+  infection.sinceStage = infection.sinceStage + 1
+  local line = nil
+  if dealt > 0 then
+    line = isPlayer(entity) and string.format("you are wracked by %s for %d", def.name, dealt)
+      or string.format("%s is wracked by %s for %d", entity.name, def.name, dealt)
+  end
+  if infection.sinceStage >= def.stageTurns and infection.stage < Disease.MAX_STAGE then
+    infection.stage = infection.stage + 1
+    infection.sinceStage = 0
+    line = isPlayer(entity) and string.format("your %s worsens", def.name)
+      or string.format("%s's %s worsens", entity.name, def.name)
+  end
+  return line
+end
+
+return Disease

src/durability.lua

@@ -0,0 +1,127 @@
+-- Weapon, armor and bow wear: unlike digging.lua's pick, a single limited-use
+-- tool discarded outright once spent, a piece of gear wears down from
+-- ordinary use but survives reaching zero - it just stops contributing to
+-- combat until repaired, exactly like disenchanting a rune off a weapon
+-- strips its bonus without destroying the weapon itself (see crafting.lua).
+-- A weapon or armor's power is baked straight into the wielder's
+-- attack/defense the instant it is equipped (see items.lua's
+-- Items.equipWeapon/equipArmor), so breaking or repairing one here adjusts
+-- that same baked total by the identical delta swapping gear already uses -
+-- never a separate "effective power" read live in combat. A bow is the one
+-- exception: its power is read live at the point of firing (see
+-- ranged.lua's Ranged.fire), so Durability.effectivePower covers that
+-- instead. Only the player's own gear wears at all - monsters have no
+-- inventory management or repair access, so wear is never applied to theirs.
+
+local Durability = {}
+
+Durability.MAX = 30
+Durability.WEAR_PER_HIT = 1
+Durability.REPAIR_COST_PER_POINT = 2
+
+-- Lazily stamps a fresh durability pair onto `item` the moment anything
+-- first asks about it, so an item built before this field existed on it
+-- (a raw table assembled somewhere this module cannot see) still gets a
+-- sensible default rather than an error.
+function Durability.ensure(item)
+  if not item.durability then
+    item.durability = Durability.MAX
+    item.maxDurability = Durability.MAX
+  end
+  return item
+end
+
+function Durability.isBroken(item)
+  Durability.ensure(item)
+  return item.durability <= 0
+end
+
+-- A broken bow contributes nothing to a shot's damage; read live in
+-- Ranged.fire in place of a bare `bow.power`.
+function Durability.effectivePower(item)
+  if not item then return 0 end
+  if Durability.isBroken(item) then return 0 end
+  return item.power or 0
+end
+
+local function isPlayerOwned(entity)
+  return entity.kind == "player"
+end
+
+-- Wears one point off `entity.weapon`, subtracting its power out of
+-- entity.attack the instant it actually breaks (never before, and never
+-- twice for the same break). A no-op, nil return, for an unarmed entity or
+-- one whose weapon already sits at zero.
+function Durability.wearWeapon(entity)
+  local item = entity.weapon
+  if not item then return nil end
+  Durability.ensure(item)
+  if item.durability <= 0 then return nil end
+  item.durability = item.durability - Durability.WEAR_PER_HIT
+  if item.durability <= 0 then
+    entity.attack = entity.attack - item.power
+    return isPlayerOwned(entity) and ("your " .. item.name .. " breaks apart from wear")
+      or (entity.name .. "'s " .. item.name .. " breaks apart from wear")
+  end
+  return nil
+end
+
+function Durability.wearArmor(entity)
+  local item = entity.armor
+  if not item then return nil end
+  Durability.ensure(item)
+  if item.durability <= 0 then return nil end
+  item.durability = item.durability - Durability.WEAR_PER_HIT
+  if item.durability <= 0 then
+    entity.defense = entity.defense - item.power
+    return isPlayerOwned(entity) and ("your " .. item.name .. " is battered to uselessness")
+      or (entity.name .. "'s " .. item.name .. " is battered to uselessness")
+  end
+  return nil
+end
+
+-- A bow's power is never baked into attack, so breaking one touches no stat
+-- - Ranged.fire simply stops reading any power out of it via
+-- Durability.effectivePower.
+function Durability.wearBow(entity)
+  local item = entity.bow
+  if not item then return nil end
+  Durability.ensure(item)
+  if item.durability <= 0 then return nil end
+  item.durability = item.durability - Durability.WEAR_PER_HIT
+  if item.durability <= 0 then
+    return isPlayerOwned(entity) and ("your " .. item.name .. " snaps from wear")
+      or (entity.name .. "'s " .. item.name .. " snaps from wear")
+  end
+  return nil
+end
+
+function Durability.missing(item)
+  Durability.ensure(item)
+  return item.maxDurability - item.durability
+end
+
+function Durability.repairCost(item)
+  return Durability.missing(item) * Durability.REPAIR_COST_PER_POINT
+end
+
+-- Spends `entity.gold` to restore `entity`'s gear in `slotName` (one of
+-- "weapon", "armor", "bow") fully, folding its power back into attack or
+-- defense if the break had already stripped it out. Fails without spending
+-- anything for an empty slot, an already-pristine item, or too thin a purse.
+function Durability.repair(entity, slotName)
+  local item = entity[slotName]
+  if not item then return false, "nothing equipped there" end
+  Durability.ensure(item)
+  if item.durability >= item.maxDurability then return false, "already in perfect condition" end
+  local cost = Durability.repairCost(item)
+  if entity.gold < cost then return false, "not enough gold" end
+  local wasBroken = item.durability <= 0
+  entity.gold = entity.gold - cost
+  item.durability = item.maxDurability
+  if wasBroken and slotName == "weapon" then entity.attack = entity.attack + item.power end
+  if wasBroken and slotName == "armor" then entity.defense = entity.defense + item.power end
+  return true, cost
+end
+
+return Durability

src/effects.lua

@@ -4,37 +4,120 @@
 
 local Status = require("status")
 local Identify = require("identify")
+local Hazards = require("hazards")
+local Resistances = require("resistances")
+local Curses = require("curses")
+local Sanity = require("sanity")
+local Disease = require("disease")
 
 local Effects = {}
 
 local handlers = {}
 
+-- Every handler below phrases its own log line by hand rather than always
+-- templating a bare "%s <third-person-singular-verb>" onto target.name,
+-- because Effects.apply's only call site (Game:useItem) always hands it the
+-- player, whose name is the pronoun "you" - a subject that takes the plain
+-- ("you heal", "you are poisoned") verb form English gives second person,
+-- not the third-person-singular form ("heals", "is") a named monster like
+-- "orc" would take. Kept branching on target.kind rather than hardcoding
+-- "you" outright so a future non-player caller (a companion drinking its
+-- own potion, say) still reads correctly without touching this file - the
+-- same isPlayer-branch convention Game:springTrap and Game:checkTerrainFor
+-- already use for the identical pronoun problem.
+local function isPlayer(target)
+  return target.kind == "player"
+end
+
 handlers.heal = function(game, target, item)
   local before = target.hp
   target.hp = math.min(target.maxHp, target.hp + item.power)
-  return { string.format("%s heals %d", target.name, target.hp - before) }
+  local healed = target.hp - before
+  return { isPlayer(target) and string.format("you heal %d", healed)
+    or string.format("%s heals %d", target.name, healed) }
 end
 
 handlers.poison = function(game, target, item)
   Status.apply(target, Status.POISON, 6, item.power)
-  return { string.format("%s is poisoned", target.name) }
+  return { isPlayer(target) and "you are poisoned" or string.format("%s is poisoned", target.name) }
 end
 
 handlers.strength = function(game, target, _)
   Status.apply(target, Status.STRENGTH, 30, 3)
-  return { string.format("%s feels mightier", target.name) }
+  return { isPlayer(target) and "you feel mightier" or string.format("%s feels mightier", target.name) }
 end
 
 handlers.haste = function(game, target, _)
   Status.apply(target, Status.HASTE, 20, 1)
-  return { string.format("%s speeds up", target.name) }
+  return { isPlayer(target) and "you speed up" or string.format("%s speeds up", target.name) }
+end
+
+handlers.fortify = function(game, target, _)
+  Status.apply(target, Status.SHIELD, 15, 1)
+  return { isPlayer(target) and "you feel fortified" or string.format("%s feels fortified", target.name) }
+end
+
+-- Same shape as haste/fortify - a timed self-buff, not a hostile effect -
+-- but see status.lua's Status.LEVITATE for what it actually unlocks: a
+-- levitating target ignores lava, chasms, ice, and ground-pressure traps
+-- entirely until it wears off (Game:checkTerrainFor/checkTrapFor).
+handlers.levitate = function(game, target, _)
+  Status.apply(target, Status.LEVITATE, 20, 1)
+  return { isPlayer(target) and "you rise off the ground" or string.format("%s rises off the ground", target.name) }
+end
+
+handlers.clarity = function(game, target, item)
+  Sanity.adjust(target, item.power)
+  return { isPlayer(target) and string.format("your mind steadies (sanity %d/%d)", Sanity.current(target), Sanity.MAX)
+    or string.format("%s's mind steadies (sanity %d/%d)", target.name, Sanity.current(target), Sanity.MAX) }
+end
+
+-- "Cleansing" always meant purging disease; it never touched the status
+-- effects (poison, burning, stun, slow, weaken, discord, confuse, blind)
+-- that every other cure-shaped word in the game implies, leaving those
+-- curable only by waiting out their duration. Now strips both.
+handlers.cure = function(game, target, _)
+  local diseaseCured = Disease.cure(target)
+  local liftedStatuses = Status.cureHostile(target)
+  local statusList = table.concat(liftedStatuses, ", ")
+  if diseaseCured and #liftedStatuses > 0 then
+    return { isPlayer(target)
+      and string.format("your affliction is cleansed away, and the %s fades", statusList)
+      or string.format("%s's affliction is cleansed away, and the %s fades", target.name, statusList) }
+  elseif diseaseCured then
+    return { isPlayer(target) and "your affliction is cleansed away"
+      or string.format("%s's affliction is cleansed away", target.name) }
+  elseif #liftedStatuses > 0 then
+    return { isPlayer(target) and string.format("your %s fades", statusList)
+      or string.format("%s's %s fades", target.name, statusList) }
+  end
+  return { isPlayer(target) and "you feel a faint tingle, but had nothing to cleanse"
+    or string.format("%s feels a faint tingle, but had nothing to cleanse", target.name) }
+end
+
+-- Same duration/potency as the confuse spell and trap (see status.lua's
+-- Status.CONFUSE and its mirrors in Game:movePlayer/Ai.act) so drinking an
+-- unidentified potion of confusion is exactly as bad as walking into a
+-- confuse trap, not a weaker or stronger flavor of the same status.
+handlers.confuse = function(game, target, _)
+  Status.apply(target, Status.CONFUSE, 6, 1)
+  return { isPlayer(target) and "your mind reels with confusion"
+    or string.format("%s's mind reels with confusion", target.name) }
+end
+
+-- Same duration/potency as the blind trap (see Game:springTrap) so drinking
+-- an unidentified potion of blindness is exactly as bad as walking into a
+-- flash trap, not a weaker or stronger flavor of the same status.
+handlers.blind = function(game, target, _)
+  Status.apply(target, Status.BLIND, 6, 1)
+  return { isPlayer(target) and "you are struck blind" or string.format("%s is struck blind", target.name) }
 end
 
 handlers.teleport = function(game, target, _)
   local x, y = game:randomFloorCell()
   if x then
     target.x, target.y = x, y
-    return { target.name .. " blinks away" }
+    return { isPlayer(target) and "you blink away" or (target.name .. " blinks away") }
   end
   return { "the teleport fizzles" }
 end
@@ -45,11 +128,28 @@ handlers.mapping = function(game, _, _)
 end
 
 handlers.identify = function(game, target, _)
+  local lines = {}
   local revealed = Identify.revealFirstUnknown(game.identify, target.inventory)
   if revealed then
-    return { "it is " .. revealed.name }
+    lines[#lines + 1] = "it is " .. revealed.name
   end
-  return { "nothing left to identify" }
+  local cursedFind = Curses.revealFirstUnknown(target)
+  if cursedFind then
+    lines[#lines + 1] = "you sense a curse upon your " .. cursedFind.name
+  end
+  if #lines == 0 then
+    lines[#lines + 1] = "nothing left to identify"
+  end
+  return lines
+end
+
+handlers.removecurse = function(game, target, _)
+  local count = Curses.cleanseWorn(target)
+  if count == 0 then
+    return { "you feel a faint tingle, but nothing you wear is cursed" }
+  end
+  return { string.format("a wave of purifying light lifts %d curse%s from your gear",
+    count, count == 1 and "" or "s") }
 end
 
 handlers.fireball = function(game, target, _)
@@ -59,12 +159,14 @@ handlers.fireball = function(game, target, _)
     if monster:isAlive() then
       local dist = math.max(math.abs(monster.x - target.x), math.abs(monster.y - target.y))
       if dist <= radius then
-        monster.hp = monster.hp - 8
+        monster.hp = monster.hp - Resistances.apply(monster, 8, Resistances.FIRE)
         Status.apply(monster, Status.BURNING, 3, 2)
+        Hazards.ignite(game.level, monster.x, monster.y, 3, 2)
         burned = burned + 1
       end
     end
   end
+  Hazards.ignite(game.level, target.x, target.y, 3, 2)
   game:cleanupDead()
   return { string.format("fire engulfs %d foes", burned) }
 end

src/elites.lua

@@ -0,0 +1,162 @@
+-- Elite monsters: rare, affixed variants of the ordinary bestiary. Builder
+-- rolls promotion once a floor's entities are already fully placed (appended
+-- dead last in Builder.build, after every other placement - artifacts, the
+-- boss, the quest board - so it can never perturb an earlier system's rng
+-- sequence, exactly like those do for their own rolls). An elite still rides
+-- the same ai.lua/abilities.lua dispatch and scheduler as any other creature;
+-- only its stats, its name, and the on-hit/on-death/lifesteal hooks Game
+-- wires in separately set it apart from a plain spawn of the same species.
+-- A floor deep enough for a second affix ("champion") draws it from the
+-- remaining pool, so a champion never doubles up on the same one.
+
+local Resistances = require("resistances")
+
+local Elites = {}
+
+Elites.MIN_DEPTH = 3
+Elites.CHAMPION_DEPTH = 7
+
+Elites.affixes = {
+  { key = "brutal",       name = "brutal",       hpMult = 1.2, attack = 3 },
+  { key = "armored",      name = "armored",      hpMult = 1.3, defense = 3 },
+  { key = "swift",        name = "swift",        speed = 30 },
+  { key = "regenerating", name = "regenerating", regen = 3 },
+  { key = "warded",       name = "warded",       resist = Resistances.RESIST },
+  { key = "vampiric",     name = "vampiric",     lifesteal = 0.5 },
+  { key = "chilling",     name = "chilling",     onHit = { status = "slow", duration = 3, potency = 1 } },
+  { key = "volatile",     name = "volatile",     onDeathDamage = 8, onDeathType = Resistances.FIRE },
+}
+
+Elites.byKey = {}
+for _, affix in ipairs(Elites.affixes) do
+  Elites.byKey[affix.key] = affix
+end
+
+-- Elemental types a "warded" roll can pick from - physical is excluded since
+-- every hit already respects the plain attack/defense floor in combat.lua.
+local RESISTABLE = {
+  Resistances.FIRE, Resistances.COLD, Resistances.POISON,
+  Resistances.LIGHTNING, Resistances.ARCANE,
+}
+
+local function applyAffix(entity, affix, rng)
+  entity.eliteAffixes[#entity.eliteAffixes + 1] = affix.key
+  if affix.hpMult then
+    local bonus = math.floor(entity.maxHp * (affix.hpMult - 1))
+    entity.maxHp = entity.maxHp + bonus
+    entity.hp = entity.hp + bonus
+  end
+  if affix.attack then
+    entity.attack = entity.attack + affix.attack
+    entity.baseAttack = entity.baseAttack + affix.attack
+  end
+  if affix.defense then
+    entity.defense = entity.defense + affix.defense
+    entity.baseDefense = entity.baseDefense + affix.defense
+  end
+  if affix.speed then entity.speed = entity.speed + affix.speed end
+  if affix.regen then entity.regen = (entity.regen or 0) + affix.regen end
+  if affix.resist then
+    local element = RESISTABLE[rng:range(1, #RESISTABLE)]
+    entity.resist = entity.resist or {}
+    if entity.resist[element] ~= Resistances.IMMUNE then
+      entity.resist[element] = affix.resist
+    end
+  end
+  entity.name = affix.name .. " " .. entity.name
+end
+
+-- Eligible for promotion: a plain bestiary spawn, never a boss (already the
+-- rarer, sturdier variant) or the passive shopkeeper.
+function Elites.eligible(entity)
+  return entity.kind == "monster" and not entity.isBoss and entity.ai ~= "vend"
+end
+
+-- Rolled once per eligible monster after a floor's entities are already
+-- placed. Mutates `entity` in place; a no-op below Elites.MIN_DEPTH, on an
+-- ineligible entity, or when the roll simply misses.
+function Elites.maybePromote(rng, entity, depth)
+  if depth < Elites.MIN_DEPTH or not Elites.eligible(entity) then return end
+  if not rng:chance(1, 6) then return end
+  entity.elite = true
+  entity.eliteAffixes = {}
+  local pool = {}
+  for i, affix in ipairs(Elites.affixes) do pool[i] = affix end
+  local rolls = 1
+  if depth >= Elites.CHAMPION_DEPTH and rng:chance(1, 3) then rolls = 2 end
+  for _ = 1, rolls do
+    if #pool == 0 then break end
+    local idx = rng:range(1, #pool)
+    applyAffix(entity, pool[idx], rng)
+    table.remove(pool, idx)
+  end
+  entity.eliteTier = #entity.eliteAffixes >= 2 and "champion" or "elite"
+end
+
+-- The first volatile affix on `entity`, if any - the death burst
+-- Game:awardKill triggers right after Abilities.onDeath.
+function Elites.explosionFor(entity)
+  if not entity.eliteAffixes then return nil end
+  for _, key in ipairs(entity.eliteAffixes) do
+    local affix = Elites.byKey[key]
+    if affix and affix.onDeathDamage then return affix end
+  end
+  return nil
+end
+
+-- The status rider (if any) a hit landed by `entity` should apply to its
+-- victim - same shape as a weapon affix's onHit (see affixes.lua), so Game
+-- can hand it straight to Status.apply.
+function Elites.onHitRider(entity)
+  if not entity.eliteAffixes then return nil end
+  for _, key in ipairs(entity.eliteAffixes) do
+    local affix = Elites.byKey[key]
+    if affix and affix.onHit then return affix.onHit end
+  end
+  return nil
+end
+
+-- Fraction of dealt damage `entity` heals back on a hit it lands, summed
+-- across its affixes (never more than one vampiric roll in practice).
+function Elites.lifestealFraction(entity)
+  if not entity.eliteAffixes then return 0 end
+  local total = 0
+  for _, key in ipairs(entity.eliteAffixes) do
+    local affix = Elites.byKey[key]
+    if affix and affix.lifesteal then total = total + affix.lifesteal end
+  end
+  return total
+end
+
+-- Bonus xp a felled elite is worth on top of its plain species reward: half
+-- again for a single-affix elite, a full second helping for a champion.
+function Elites.xpBonus(entity, baseXp)
+  if not entity.elite then return 0 end
+  local mult = entity.eliteTier == "champion" and 1.0 or 0.5
+  return math.floor(baseXp * mult)
+end
+
+-- Fired from Game:awardKill right after Abilities.onDeath: a volatile
+-- elite's corpse bursts, scorching the player and any companion or monster
+-- adjacent to it (itself excluded) for its cataloged damage and type.
+function Elites.onDeath(game, monster)
+  local affix = Elites.explosionFor(monster)
+  if not affix then return nil end
+  local hit = {}
+  local targets = { game.player }
+  for _, other in ipairs(game:currentEntities()) do targets[#targets + 1] = other end
+  for _, victim in ipairs(targets) do
+    if victim ~= monster and victim:isAlive()
+      and math.abs(victim.x - monster.x) <= 1 and math.abs(victim.y - monster.y) <= 1 then
+      local dealt = Resistances.apply(victim, affix.onDeathDamage, affix.onDeathType)
+      if dealt > 0 then
+        victim.hp = victim.hp - dealt
+        hit[#hit + 1] = string.format("%s for %d", victim.name, dealt)
+      end
+    end
+  end
+  if #hit == 0 then return nil end
+  return string.format("%s bursts, scorching %s", monster.name, table.concat(hit, ", "))
+end
+
+return Elites

src/encumbrance.lua

@@ -0,0 +1,123 @@
+-- Carry weight. Every item kind has a physical weight (gear scales a little
+-- with its power, the way a heavier blade hits harder); a carrier's capacity
+-- grows with level, the same knob progression.lua turns for hp. Exceeding
+-- capacity does not block a pickup outright - it slows the carrier down
+-- instead (see Entity:effectiveSpeed), and a wide overage on top of that also
+-- costs defense, the same shape a status.lua debuff takes (see
+-- Entity:effectiveDefense). Nothing here is persisted: weight is entirely a
+-- function of entity.inventory and entity.level, both already serialized, so
+-- a save/load round trip recomputes the identical tier for free.
+--
+-- Monsters are never excluded from these checks (there is no species flag to
+-- opt out), but their inventory is always empty in practice - abilities.lua
+-- and combat.lua never stash loot on a monster - so in play this only ever
+-- matters for the player.
+
+local Items = require("items")
+
+local Encumbrance = {}
+
+Encumbrance.BASE_CAPACITY = 12
+Encumbrance.CAPACITY_PER_LEVEL = 4
+Encumbrance.BURDENED_MULT = 1.5
+
+Encumbrance.LIGHT = "light"
+Encumbrance.BURDENED = "burdened"
+Encumbrance.OVERLOADED = "overloaded"
+
+Encumbrance.BURDENED_SPEED_PENALTY = -20
+Encumbrance.OVERLOADED_SPEED_PENALTY = -45
+Encumbrance.OVERLOADED_DEFENSE_PENALTY = -2
+
+-- Base weight per item kind, before any power-scaling below. Kinds absent
+-- here (gold, keys) default to a flat 1 rather than 0: even a featherweight
+-- trinket takes up some of the pack, and a strictly-zero-weight kind would
+-- let a hoard of them carry for free.
+local BASE_WEIGHT = {
+  [Items.POTION] = 2,
+  [Items.SCROLL] = 1,
+  [Items.WEAPON] = 6,
+  [Items.ARMOR] = 9,
+  [Items.RING] = 1,
+  [Items.FOOD] = 3,
+  [Items.KEY] = 1,
+  [Items.TOME] = 4,
+  [Items.AMULET] = 2,
+  [Items.BOW] = 7,
+  [Items.AMMO] = 1,
+  [Items.GOLD] = 0,
+  [Items.GEM] = 1,
+  [Items.CHARM] = 2,
+  [Items.KIT] = 3,
+  [Items.HERB] = 1,
+  [Items.CONTRACT] = 1,
+}
+
+-- Kinds whose power rating (a straightforward proxy for how much metal went
+-- into them) adds a little extra weight on top of the flat base.
+local POWER_SCALES = {
+  [Items.WEAPON] = true,
+  [Items.ARMOR] = true,
+  [Items.BOW] = true,
+}
+
+-- Kinds that stack into one inventory slot via a `count`/`amount` field, so
+-- their weight must scale with the stack rather than being charged once.
+local STACK_FIELD = {
+  [Items.AMMO] = "count",
+  [Items.GOLD] = "amount",
+}
+
+function Encumbrance.itemWeight(item)
+  local weight = BASE_WEIGHT[item.kind] or 1
+  if POWER_SCALES[item.kind] then
+    weight = weight + (item.power or 0) // 3
+  end
+  local stackField = STACK_FIELD[item.kind]
+  if stackField then
+    weight = weight * (item[stackField] or 1)
+  end
+  return weight
+end
+
+-- Loose inventory plus whatever is currently worn or wielded: a sword on
+-- your belt weighs exactly as much as one in your pack.
+function Encumbrance.carriedWeight(entity)
+  local total = 0
+  for _, item in ipairs(entity.inventory) do
+    total = total + Encumbrance.itemWeight(item)
+  end
+  for _, slot in ipairs({ "weapon", "armor", "ring", "bow" }) do
+    local equipped = entity[slot]
+    if equipped then total = total + Encumbrance.itemWeight(equipped) end
+  end
+  return total
+end
+
+function Encumbrance.capacityFor(entity)
+  return Encumbrance.BASE_CAPACITY + (entity.level or 1) * Encumbrance.CAPACITY_PER_LEVEL
+end
+
+function Encumbrance.tierFor(entity)
+  local carried = Encumbrance.carriedWeight(entity)
+  local capacity = Encumbrance.capacityFor(entity)
+  if carried <= capacity then return Encumbrance.LIGHT end
+  if carried <= capacity * Encumbrance.BURDENED_MULT then return Encumbrance.BURDENED end
+  return Encumbrance.OVERLOADED
+end
+
+function Encumbrance.speedPenalty(entity)
+  local tier = Encumbrance.tierFor(entity)
+  if tier == Encumbrance.BURDENED then return Encumbrance.BURDENED_SPEED_PENALTY end
+  if tier == Encumbrance.OVERLOADED then return Encumbrance.OVERLOADED_SPEED_PENALTY end
+  return 0
+end
+
+function Encumbrance.defensePenalty(entity)
+  if Encumbrance.tierFor(entity) == Encumbrance.OVERLOADED then
+    return Encumbrance.OVERLOADED_DEFENSE_PENALTY
+  end
+  return 0
+end
+
+return Encumbrance

src/entity.lua

@@ -3,6 +3,11 @@
 -- and speed drive the turn scheduler; statuses layer temporary modifiers on top.
 
 local Status = require("status")
+local Encumbrance = require("encumbrance")
+local Momentum = require("momentum")
+local Sanity = require("sanity")
+local Proficiency = require("proficiency")
+local Hunger = require("hunger")
 
 local Entity = {}
 Entity.__index = Entity
@@ -30,6 +35,8 @@ function Entity.new(spec)
     weapon = nil,
     armor = nil,
     ring = nil,
+    bow = nil,
+    pick = nil,
   }, Entity)
 end
 
@@ -38,19 +45,25 @@ function Entity:isAlive()
 end
 
 function Entity:effectiveAttack()
-  return self.attack + Status.attackModifier(self)
+  return self.attack + Status.attackModifier(self) + Momentum.attackBonus(self) + Sanity.attackPenalty(self)
+    + Proficiency.attackBonus(self) + Hunger.attackPenalty(self)
 end
 
 function Entity:effectiveDefense()
-  return self.defense
+  return self.defense + Status.defenseModifier(self) + Encumbrance.defensePenalty(self) + Sanity.defensePenalty(self)
+    + Hunger.defensePenalty(self)
 end
 
 function Entity:effectiveSpeed()
-  local speed = self.speed + Status.speedModifier(self)
+  local speed = self.speed + Status.speedModifier(self) + Encumbrance.speedPenalty(self)
   if speed < 10 then speed = 10 end
   return speed
 end
 
+function Entity:encumbranceTier()
+  return Encumbrance.tierFor(self)
+end
+
 function Entity:toData()
   return {
     id = self.id,
@@ -66,6 +79,54 @@ function Entity:toData()
     weapon = self.weapon,
     armor = self.armor,
     ring = self.ring,
+    bow = self.bow,
+    pick = self.pick,
+    regen = self.regen,
+    onDeath = self.onDeath,
+    breath = self.breath,
+    ability = self.ability,
+    summonSpecies = self.summonSpecies,
+    summonedBy = self.summonedBy,
+    cooldown = self.cooldown,
+    fleeing = self.fleeing,
+    stolen = self.stolen,
+    splitGen = self.splitGen,
+    hostile = self.hostile,
+    isBoss = self.isBoss,
+    bossKey = self.bossKey,
+    enraged = self.enraged,
+    desperate = self.desperate,
+    channeling = self.channeling,
+    novaSpent = self.novaSpent,
+    resist = self.resist,
+    faction = self.faction,
+    provoked = self.provoked,
+    elite = self.elite,
+    eliteAffixes = self.eliteAffixes,
+    eliteTier = self.eliteTier,
+    mimic = self.mimic,
+    grave = self.grave,
+    graveClass = self.graveClass,
+    graveGold = self.graveGold,
+    graveEssence = self.graveEssence,
+    proficiency = self.proficiency,
+    awareness = self.awareness,
+    lastKnownX = self.lastKnownX,
+    lastKnownY = self.lastKnownY,
+    lostTurns = self.lostTurns,
+    searchTurns = self.searchTurns,
+    combo = self.combo,
+    decay = self.decay,
+    wage = self.wage,
+    loyalty = self.loyalty,
+    wet = self.wet,
+    nemesis = self.nemesis,
+    nemesisGrudge = self.nemesisGrudge,
+    disease = self.disease,
+    biteDisease = self.biteDisease,
+    companionXp = self.companionXp,
+    companionLevel = self.companionLevel,
+    companionHealBonus = self.companionHealBonus,
   }
 end
 

src/events.lua

@@ -0,0 +1,89 @@
+-- Timed dungeon-wide events. Unlike atmosphere.lua's single weather reading
+-- drawn once at generation and fixed for a floor's entire lifetime, an
+-- event can start and end mid-visit: from depth two on, any turn with none
+-- already running has a small chance of rolling one fresh, and a running
+-- one always expires back to nothing after a fixed duration rather than
+-- lingering for the rest of the floor. Only one runs at a time.
+-- level.event is nil or { key, turnsLeft }, plain data like level.weather,
+-- so it serializes with no special save-format handling.
+
+local Events = {}
+
+Events.BLOODMOON = "bloodmoon"
+Events.RICHVEINS = "richveins"
+Events.HUSH = "hush"
+
+-- Fixed order so a given rng draw always names the same event.
+Events.order = { Events.BLOODMOON, Events.RICHVEINS, Events.HUSH }
+
+Events.DURATION = 15
+
+Events.START_NUMERATOR = 1
+Events.START_DENOMINATOR = 60
+
+Events.BLOODMOON_MULTIPLIER = 1.5
+Events.RICHVEINS_MULTIPLIER = 2
+Events.HUSH_SIGHT_PENALTY = 1
+
+function Events.describe(key)
+  if key == Events.BLOODMOON then return "a bloodmoon rises; the monsters here hit harder" end
+  if key == Events.RICHVEINS then return "the walls hum with rich veins; essence flows freely" end
+  if key == Events.HUSH then return "a hush falls over the floor, dulling your senses" end
+  return nil
+end
+
+function Events.endDescribe(key)
+  if key == Events.BLOODMOON then return "the bloodmoon fades" end
+  if key == Events.RICHVEINS then return "the veins fall quiet again" end
+  if key == Events.HUSH then return "the hush lifts" end
+  return nil
+end
+
+-- A monster's raw attack-minus-defense swing at the player is scaled by
+-- this multiplier, read live wherever a monster lands a hit
+-- (Game:monsterMelee, Game:monsterShoot, Game:triggerMimic's ambush) -
+-- never baked permanently into a monster's own stats the way
+-- atmosphere.lua's INFESTED reading is, since it must lift again the
+-- instant the event ends.
+function Events.monsterDamageMultiplier(event)
+  if event and event.key == Events.BLOODMOON then return Events.BLOODMOON_MULTIPLIER end
+  return 1
+end
+
+-- Essence earned from a kill (Game:awardKill) or an ore vein
+-- (Nodes.harvest) is scaled by this multiplier, read live at the point
+-- essence is actually credited.
+function Events.essenceMultiplier(event)
+  if event and event.key == Events.RICHVEINS then return Events.RICHVEINS_MULTIPLIER end
+  return 1
+end
+
+-- Read alongside atmosphere.lua's own sightPenalty in Game:effectiveRadius.
+function Events.sightPenalty(event)
+  if event and event.key == Events.HUSH then return Events.HUSH_SIGHT_PENALTY end
+  return 0
+end
+
+-- Advances a running event's clock by one turn, or rolls a fresh one onto
+-- `level` when none is running. Returns a log line on start or expiry, nil
+-- on an ordinary quiet turn - exactly like sanity.lua's Sanity.tick, which
+-- reports only on a tier crossing rather than every single call.
+function Events.step(level, rng)
+  if level.event then
+    level.event.turnsLeft = level.event.turnsLeft - 1
+    if level.event.turnsLeft <= 0 then
+      local line = Events.endDescribe(level.event.key)
+      level.event = nil
+      return line
+    end
+    return nil
+  end
+  if level.depth < 2 or not rng:chance(Events.START_NUMERATOR, Events.START_DENOMINATOR) then
+    return nil
+  end
+  local key = rng:pick(Events.order)
+  level.event = { key = key, turnsLeft = Events.DURATION }
+  return Events.describe(key)
+end
+
+return Events

src/examine.lua

@@ -0,0 +1,206 @@
+-- Detailed, read-only inspection of a single inventory item or a visible
+-- monster. Aggregates facts that several other modules already track (an
+-- affix's on-hit rider, a socketed gem's element, a runeword's live bonus,
+-- an elite's affix names, a monster's resistances/awareness/status effects)
+-- into one readable report - none of which any existing HUD line
+-- (render.lua's status panel, commands.lua's own inventory/look) surfaces
+-- beyond a bare name. Every function here is read-only: it never mutates
+-- the item or monster it describes, and never spends a turn (see
+-- commands.lua's own examine handler).
+
+local Items = require("items")
+local Identify = require("identify")
+local Curses = require("curses")
+local Durability = require("durability")
+local Runewords = require("runewords")
+local Sets = require("sets")
+local Shop = require("shop")
+local Resistances = require("resistances")
+local Factions = require("factions")
+local Stealth = require("stealth")
+local Disease = require("disease")
+
+local Examine = {}
+
+local AWARENESS_LABEL = {
+  [Stealth.DORMANT] = "asleep",
+  [Stealth.SEARCHING] = "searching for you",
+  [Stealth.HUNTING] = "hunting you",
+}
+
+-- Joins whichever of attack/defense/regen a runeword or set threshold bonus
+-- carries, in a fixed order, so the same helper reads either shape.
+local function bonusText(bonus)
+  local parts = {}
+  if bonus.attack and bonus.attack ~= 0 then parts[#parts + 1] = string.format("attack +%d", bonus.attack) end
+  if bonus.defense and bonus.defense ~= 0 then parts[#parts + 1] = string.format("defense +%d", bonus.defense) end
+  if bonus.regen and bonus.regen ~= 0 then parts[#parts + 1] = string.format("regen +%d", bonus.regen) end
+  return table.concat(parts, ", ")
+end
+
+local NO_PRICE = { [Items.GOLD] = true, [Items.KEY] = true }
+
+-- Extra facts specific to one gear/consumable kind, appended after the
+-- shared label; nil for kinds with nothing beyond their name worth calling
+-- out (a plain key, a riftstone shard...).
+local function kindDetail(item)
+  if item.kind == Items.WEAPON or item.kind == Items.ARMOR or item.kind == Items.BOW then
+    local parts = { string.format("power %d", item.power) }
+    if item.range then parts[#parts + 1] = "range " .. item.range end
+    if item.damageType then parts[#parts + 1] = "deals " .. item.damageType .. " damage" end
+    Durability.ensure(item)
+    if Durability.isBroken(item) then
+      parts[#parts + 1] = string.format("durability %d/%d (broken)", item.durability, item.maxDurability)
+    else
+      parts[#parts + 1] = string.format("durability %d/%d", item.durability, item.maxDurability)
+    end
+    if item.temper and item.temper > 0 then parts[#parts + 1] = string.format("tempered +%d", item.temper) end
+    return table.concat(parts, ", ")
+  elseif item.kind == Items.RING then
+    return string.format("attack +%d, defense +%d", item.attack, item.defense)
+  elseif item.kind == Items.FOOD then
+    return string.format("restores %d nutrition", item.nutrition)
+  elseif item.kind == Items.TOME then
+    return "teaches the spell: " .. item.spell
+  elseif item.kind == Items.AMMO then
+    return string.format("%d in the stack", item.count)
+  elseif item.kind == Items.CHARM then
+    return "summons a companion: " .. item.companion
+  elseif item.kind == Items.KIT then
+    return "trap effect: " .. item.effect
+  elseif item.kind == Items.CONTRACT then
+    return "hires: " .. item.hireling
+  elseif item.kind == Items.PICK then
+    return string.format("%d uses left", item.uses)
+  elseif item.kind == Items.GEM then
+    return string.format("tier %d, power %d", item.tier, item.power)
+  end
+  return nil
+end
+
+-- Every non-kind-specific trait a piece of gear may carry, appended in a
+-- fixed order regardless of which of them are actually present.
+local function gearTraits(item, lines)
+  if item.affix then
+    local desc = item.affix.name
+    if item.affix.onHit then
+      desc = string.format("%s (on hit: %s, %d turns, potency %d)", desc,
+        item.affix.onHit.status, item.affix.onHit.duration, item.affix.onHit.potency)
+    end
+    lines[#lines + 1] = "affix: " .. desc
+  end
+
+  if item.artifact then
+    lines[#lines + 1] = "artifact power: " .. (item.unique or "passive bonus")
+  end
+
+  if item.set then
+    local spec = Sets.byKey[item.set]
+    lines[#lines + 1] = "set piece: " .. (spec and spec.name or item.set)
+  end
+
+  if item.socket then
+    lines[#lines + 1] = string.format("socketed: tier %d %s gem", item.socket.tier, item.socket.element)
+  end
+
+  if item.runes and #item.runes > 0 then
+    local word = Runewords.activeWord(item)
+    if word then
+      lines[#lines + 1] = string.format("runeword %s: %s", word.name, bonusText(word))
+    else
+      lines[#lines + 1] = "runes: " .. table.concat(item.runes, "-")
+    end
+  end
+
+  if item.resist then
+    local parts = {}
+    for damageType, tier in pairs(item.resist) do
+      parts[#parts + 1] = damageType .. " " .. tier
+    end
+    table.sort(parts)
+    lines[#lines + 1] = "grants: " .. table.concat(parts, ", ")
+  end
+
+  if Curses.isCursed(item) and Curses.isRevealed(item) then
+    lines[#lines + 1] = "cursed (" .. item.curseKind .. ")"
+  end
+end
+
+-- A multi-line, semicolon-joined report on a single inventory item: its
+-- (possibly still-disguised, see identify.lua) label, then whatever the
+-- fields above actually populate. Unidentified potions/scrolls only ever
+-- reach the label + value lines, since kindDetail and gearTraits both key
+-- off fields those kinds never carry.
+function Examine.item(identifyState, item)
+  local lines = { Curses.label(item, Identify.label(identifyState, item)) }
+  local detail = kindDetail(item)
+  if detail then lines[#lines + 1] = detail end
+  gearTraits(item, lines)
+  if not NO_PRICE[item.kind] then
+    lines[#lines + 1] = "worth " .. Shop.priceOf(item) .. " gold"
+  end
+  return table.concat(lines, "; ")
+end
+
+-- A multi-line, semicolon-joined report on a monster the player can
+-- currently see: its combat numbers (already folded through
+-- Entity:effectiveAttack/effectiveDefense, so momentum/hunger/sanity
+-- modifiers show up exactly as they would land the next swing), its
+-- alertness, standing faction and reputation tier, elite/boss tags, any
+-- non-normal resistance, and whatever status effects currently afflict it.
+function Examine.monster(player, monster)
+  local lines = { monster.name }
+  lines[#lines + 1] = string.format("hp %d/%d, attack %d, defense %d",
+    monster.hp, monster.maxHp, monster:effectiveAttack(), monster:effectiveDefense())
+  lines[#lines + 1] = "awareness: " .. (AWARENESS_LABEL[monster.awareness] or "hunting you")
+  if monster.provoked then lines[#lines + 1] = "provoked" end
+
+  if monster.faction then
+    local tier = Factions.tier(Factions.reputationFor(player, monster.faction))
+    lines[#lines + 1] = string.format("faction: %s (%s)", monster.faction, tier)
+  end
+
+  if monster.elite then
+    lines[#lines + 1] = (monster.eliteTier or "elite") .. ": " .. table.concat(monster.eliteAffixes or {}, ", ")
+  end
+
+  if monster.isBoss then
+    local tags = {}
+    if monster.enraged then tags[#tags + 1] = "enraged" end
+    if monster.desperate then tags[#tags + 1] = "desperate" end
+    lines[#lines + 1] = #tags > 0 and ("boss, " .. table.concat(tags, ", ")) or "boss"
+  end
+
+  local resistParts = {}
+  for _, damageType in ipairs(Resistances.TYPES) do
+    local tier = Resistances.tierOf(monster, damageType)
+    if tier ~= Resistances.NORMAL then
+      resistParts[#resistParts + 1] = damageType .. " " .. tier
+    end
+  end
+  if #resistParts > 0 then lines[#lines + 1] = "resistances: " .. table.concat(resistParts, ", ") end
+
+  if monster.statuses and #monster.statuses > 0 then
+    local parts = {}
+    for _, active in ipairs(monster.statuses) do
+      parts[#parts + 1] = string.format("%s (%d)", active.kind, active.duration)
+    end
+    lines[#lines + 1] = "afflicted: " .. table.concat(parts, ", ")
+  end
+
+  -- Only reachable via infighting.lua's own bite chance (a rival monster or
+  -- the player's own companion/hireling/thrall can now catch a disease from
+  -- a carrier's bite, not just the player) - shown the same way a
+  -- durability-damaged item's examine line reports a fact only visible
+  -- through inspection, not the bare glyph on the map.
+  if Disease.isInfected(monster) then
+    local def = Disease.defs[monster.disease.key]
+    lines[#lines + 1] = Disease.hasErupted(monster)
+      and string.format("diseased: %s (stage %d)", def.name, monster.disease.stage)
+      or string.format("diseased: %s (incubating)", def.name)
+  end
+
+  return table.concat(lines, "; ")
+end
+
+return Examine

src/export.lua

@@ -0,0 +1,48 @@
+-- Renders meta.lua's own leaderboard as CSV text, one row per entry, for a
+-- player who wants their run history in a spreadsheet rather than
+-- warren.lua's own --report listing. A leaderboard entry's exact field set
+-- (see leaderboard.lua's Leaderboard.record) becomes the exact column set
+-- here, so the header row and every data row are always built from the
+-- same list and can never drift apart from each other.
+
+local Compendium = require("compendium")
+
+local Export = {}
+
+Export.COLUMNS = { "rank", "score", "className", "depth", "turn", "won", "seed" }
+Export.COMPENDIUM_COLUMNS = { "key", "name", "seen", "kills" }
+
+local function csvField(value)
+  if value == nil then return "" end
+  if value == true then return "true" end
+  if value == false then return "false" end
+  return tostring(value)
+end
+
+-- One CSV document: a header row naming Export.COLUMNS, then one row per
+-- `board` entry in its own existing order (best score first, see
+-- Leaderboard.record) with a 1-based rank column prepended.
+function Export.leaderboardCsv(board)
+  local lines = { table.concat(Export.COLUMNS, ",") }
+  for rank, entry in ipairs(board) do
+    local row = { rank, entry.score, entry.className, entry.depth, entry.turn, entry.won, entry.seed }
+    for i, value in ipairs(row) do row[i] = csvField(value) end
+    lines[#lines + 1] = table.concat(row, ",")
+  end
+  return table.concat(lines, "\n") .. "\n"
+end
+
+-- One CSV document over every species Compendium.entries knows about (see
+-- compendium.lua), sighted or not - so an export always lists the whole
+-- bestiary's shape, not just whatever a given save has stumbled across.
+function Export.compendiumCsv(compendium)
+  local lines = { table.concat(Export.COMPENDIUM_COLUMNS, ",") }
+  for _, entry in ipairs(Compendium.entries(compendium)) do
+    local row = { entry.key, entry.name, entry.seen, entry.kills }
+    for i, value in ipairs(row) do row[i] = csvField(value) end
+    lines[#lines + 1] = table.concat(row, ",")
+  end
+  return table.concat(lines, "\n") .. "\n"
+end
+
+return Export

src/factions.lua

@@ -0,0 +1,130 @@
+-- Faction standing. Every hostile species in the bestiary carries a `faction`
+-- tag; the player carries a `reputation` table scoring how each faction feels
+-- about them, starting neutral (an absent entry reads as 0). Killing a
+-- faction's members sours that score; paying tribute or turning in a bounty
+-- sweetens it. Reputation then feeds back into the world two ways: a
+-- tribal faction tagged "neutral" (see neutralFactions) leaves its members
+-- passively unprovoked until the player either strikes first or has enraged
+-- the whole tribe by other means, and the merchant guild's prices rise or
+-- fall with how the player stands with it.
+
+local Factions = {}
+
+Factions.MERCHANT = "merchant"
+Factions.GOBLINOID = "goblinoid"
+Factions.VERMIN = "vermin"
+Factions.ORCISH = "orcish"
+Factions.UNDEAD = "undead"
+Factions.BEAST = "beast"
+Factions.CULT = "cult"
+Factions.DRAKE = "drake"
+Factions.BANDIT = "bandit"
+
+-- Factions whose rank-and-file stay passive - see Factions.isWary - unless
+-- provoked in melee/at range or already hated into open hostility.
+Factions.neutralFactions = { [Factions.GOBLINOID] = true }
+
+-- Faction pairs that loathe each other regardless of the player: two
+-- monsters from an unrelated pair here fight on sight if they ever share a
+-- floor (see infighting.lua), no discord spell required. Listed once per
+-- pair; Factions.areRivals checks both directions. Deliberately excludes any
+-- faction pairing with a summon relationship (CULT raises UNDEAD minions)
+-- so a caster is never made to loathe its own summoned brood.
+Factions.RIVALRIES = {
+  { Factions.GOBLINOID, Factions.ORCISH },
+  { Factions.BANDIT, Factions.MERCHANT },
+  { Factions.VERMIN, Factions.BEAST },
+}
+
+function Factions.areRivals(factionA, factionB)
+  if not factionA or not factionB or factionA == factionB then return false end
+  for _, pair in ipairs(Factions.RIVALRIES) do
+    if (pair[1] == factionA and pair[2] == factionB) or (pair[1] == factionB and pair[2] == factionA) then
+      return true
+    end
+  end
+  return false
+end
+
+local HOSTILE_MAX = -30
+local UNFRIENDLY_MAX = -10
+local FRIENDLY_MIN = 25
+local HONORED_MIN = 60
+
+local PRICE_MULTIPLIER = {
+  hostile = 1.5, unfriendly = 1.15, neutral = 1.0, friendly = 0.85, honored = 0.65,
+}
+
+local KILL_PENALTY = 5
+local BOSS_KILL_PENALTY = 15
+local BASE_APPEASE_COST = 20
+local APPEASE_GAIN = 15
+
+function Factions.reputationFor(player, faction)
+  return (player.reputation and player.reputation[faction]) or 0
+end
+
+-- The named tier a raw reputation score falls into, from most soured to most
+-- warm. Ties resolve toward the harsher tier so a score sitting exactly on a
+-- boundary reads as the tier it just reached rather than the one it left.
+function Factions.tier(rep)
+  if rep <= HOSTILE_MAX then return "hostile" end
+  if rep <= UNFRIENDLY_MAX then return "unfriendly" end
+  if rep >= HONORED_MIN then return "honored" end
+  if rep >= FRIENDLY_MIN then return "friendly" end
+  return "neutral"
+end
+
+-- Nudges `faction`'s standing by `delta`, clamped to +-100, creating the
+-- player's reputation table on first use.
+function Factions.adjust(player, faction, delta)
+  player.reputation = player.reputation or {}
+  local updated = Factions.reputationFor(player, faction) + delta
+  if updated > 100 then updated = 100 end
+  if updated < -100 then updated = -100 end
+  player.reputation[faction] = updated
+  return updated
+end
+
+-- Called once per monster a player action fells: unfactioned kills (traps,
+-- hazards with no owning species) are simply ignored.
+function Factions.registerKill(player, target)
+  if not target.faction then return end
+  Factions.adjust(player, target.faction, target.isBoss and -BOSS_KILL_PENALTY or -KILL_PENALTY)
+end
+
+-- Whether `faction`'s members currently hold back from attacking on sight.
+-- Non-tribal factions are never wary; a tribal one stops being wary the
+-- instant the whole faction's standing curdles into open hostility.
+function Factions.isWary(player, monster)
+  local faction = monster.faction
+  if not (faction and Factions.neutralFactions[faction]) then return false end
+  if monster.provoked then return false end
+  return Factions.tier(Factions.reputationFor(player, faction)) ~= "hostile"
+end
+
+function Factions.priceMultiplier(player, faction)
+  return PRICE_MULTIPLIER[Factions.tier(Factions.reputationFor(player, faction))]
+end
+
+-- Gold cost of the next tribute to `faction`: a flat base that climbs the
+-- deeper the grudge already runs, so digging out of "hostile" costs more
+-- than smoothing over a merely "unfriendly" one.
+function Factions.appeaseCost(player, faction)
+  return BASE_APPEASE_COST + math.max(0, -Factions.reputationFor(player, faction)) * 2
+end
+
+-- Spends gold to buy `faction`'s standing up by a fixed amount. Returns
+-- (true, costPaid) on success; (false, cost) when the player cannot afford
+-- it; (false, 0) when the faction is already maxed out and has nothing left
+-- to sell.
+function Factions.appease(player, faction)
+  if Factions.reputationFor(player, faction) >= 100 then return false, 0 end
+  local cost = Factions.appeaseCost(player, faction)
+  if player.gold < cost then return false, cost end
+  player.gold = player.gold - cost
+  Factions.adjust(player, faction, APPEASE_GAIN)
+  return true, cost
+end
+
+return Factions

src/gen/init.lua

@@ -12,10 +12,15 @@ Gen.generators = {
   bsp = require("gen.bsp").generate,
   cellular = require("gen.cellular").generate,
   drunkard = require("gen.drunkard").generate,
+  maze = require("gen.maze").generate,
 }
 
 -- Deterministic ordering of names for callers that want to cycle generators by
--- depth without depending on hash iteration order.
+-- depth without depending on hash iteration order. gen.maze is deliberately
+-- absent: builder.lua's chosenGenerator indexes into this list by depth, and
+-- every existing seed-pinned test downstream of it already assumes today's
+-- four-way cycle. Reaching a maze floor is always explicit, via
+-- options.generator = "maze" (see Gen.has/Gen.build below).
 Gen.order = { "rooms", "bsp", "cellular", "drunkard" }
 
 function Gen.has(name)

src/gen/maze.lua

@@ -0,0 +1,90 @@
+-- Recursive-backtracker maze: a perfect spanning tree of one-wide corridors
+-- over a grid of cells spaced two tiles apart, carved by an iterative
+-- depth-first walk (an explicit stack, never Lua's own call stack, so
+-- nothing here bounds how large a maze can grow). The result is a topology
+-- none of the other generators produce - dense and twisty, with exactly one
+-- path between any two cells - unlike the open rooms of gen.rooms/gen.bsp
+-- or the organic blobs of gen.cellular/gen.drunkard. A braiding pass
+-- afterward knocks down a fixed fraction of the walls still separating two
+-- already-carved cells, so a fraction of what would otherwise be dead ends
+-- gain a second way out instead. Selectable like any other entry in
+-- gen.init's registry, but deliberately left out of Gen.order: nothing
+-- downstream (builder.lua's rng-ordering discipline, every seed-pinned
+-- depth test) currently expects the auto-cycle to ever hand it a floor, and
+-- inserting a fifth entry there would reshuffle which of the existing four
+-- generators every depth from five onward gets, and with it every rng draw
+-- a builder places afterward. A maze floor is instead reached deliberately,
+-- via options.generator = "maze".
+
+local Map = require("map")
+local Tiles = require("tiles")
+
+local Maze = {}
+
+Maze.BRAID_NUMERATOR = 1
+Maze.BRAID_DENOMINATOR = 5
+
+local DIRS = { { 2, 0 }, { -2, 0 }, { 0, 2 }, { 0, -2 } }
+
+local function shuffledDirs(rng)
+  local dirs = { DIRS[1], DIRS[2], DIRS[3], DIRS[4] }
+  for i = 4, 2, -1 do
+    local j = rng:range(1, i)
+    dirs[i], dirs[j] = dirs[j], dirs[i]
+  end
+  return dirs
+end
+
+function Maze.generate(width, height, rng, options)
+  options = options or {}
+  local braidNumerator = options.braidNumerator or Maze.BRAID_NUMERATOR
+  local braidDenominator = options.braidDenominator or Maze.BRAID_DENOMINATOR
+  local map = Map.new(width, height)
+
+  local function key(x, y) return y * width + x end
+  local visited = {}
+
+  local startX, startY = 2, 2
+  visited[key(startX, startY)] = true
+  map:set(startX, startY, Tiles.FLOOR)
+  local stack = { { startX, startY } }
+
+  while #stack > 0 do
+    local top = stack[#stack]
+    local cx, cy = top[1], top[2]
+    local advanced = false
+    for _, dir in ipairs(shuffledDirs(rng)) do
+      local nx, ny = cx + dir[1], cy + dir[2]
+      if nx >= 2 and ny >= 2 and nx <= width - 1 and ny <= height - 1 and not visited[key(nx, ny)] then
+        local wx, wy = cx + dir[1] // 2, cy + dir[2] // 2
+        map:set(wx, wy, Tiles.FLOOR)
+        map:set(nx, ny, Tiles.FLOOR)
+        visited[key(nx, ny)] = true
+        stack[#stack + 1] = { nx, ny }
+        advanced = true
+        break
+      end
+    end
+    if not advanced then stack[#stack] = nil end
+  end
+
+  -- Braiding: a wall cell with floor on exactly one opposing pair of sides
+  -- (east-west or north-south) sits between two cells the backtracker above
+  -- already connected some longer way around; knocking a fixed fraction of
+  -- these down trims some, but never all, of the maze's dead ends.
+  for y = 3, height - 2 do
+    for x = 3, width - 2 do
+      if map:get(x, y) == Tiles.WALL then
+        local linksEastWest = map:get(x - 1, y) == Tiles.FLOOR and map:get(x + 1, y) == Tiles.FLOOR
+        local linksNorthSouth = map:get(x, y - 1) == Tiles.FLOOR and map:get(x, y + 1) == Tiles.FLOOR
+        if (linksEastWest or linksNorthSouth) and rng:chance(braidNumerator, braidDenominator) then
+          map:set(x, y, Tiles.FLOOR)
+        end
+      end
+    end
+  end
+
+  return map
+end
+
+return Maze

src/graves.lua

@@ -0,0 +1,106 @@
+-- Cross-run bones: the moment a run ends in death (see warren.lua's --meta
+-- path and Game:graveEntry), a grave entry is appended to meta.lua's
+-- persistent save - what the fallen was still carrying, and how deep they
+-- got. From the very next run on, Builder.build may roll one of those
+-- graves onto a floor at or shallower than where it was dug (bones drift
+-- upward over time, never down - see Graves.eligibleFor) as an inert
+-- floorItem, drawn dead last of all so a run without any recorded deaths
+-- (or one played without --meta at all) makes no extra rng draw and its
+-- floor layouts stay byte-identical to before this module existed.
+--
+-- Unlike mimics.lua's disguise, a grave marker is honest about what it is -
+-- disturbing it (Game:pickupHere, mirroring Game:triggerMimic) wakes a
+-- vengeful shade rather than pretending to be ordinary loot. The shade's
+-- hp and attack scale with how much the fallen was carrying at death, and
+-- felling it in turn pays out a fraction of that same hoard - a richer
+-- death makes for a tougher fight and a richer reward, but always strictly
+-- less than what was actually lost.
+
+local Entity = require("entity")
+local Factions = require("factions")
+
+local Graves = {}
+
+-- Oldest graves fall off once a save accumulates more than this many, so a
+-- long-lived meta file never grows without bound.
+Graves.MAX_RECORDED = 20
+
+-- Appends `entry` (see Game:graveEntry) to meta.graves, most recent first,
+-- trimming anything past Graves.MAX_RECORDED.
+function Graves.record(meta, entry)
+  meta.graves = meta.graves or {}
+  table.insert(meta.graves, 1, entry)
+  while #meta.graves > Graves.MAX_RECORDED do
+    table.remove(meta.graves)
+  end
+end
+
+-- Graves eligible to be rolled onto `depth`: any dug at that depth or
+-- deeper. A grave dug on floor 7 can still turn up waiting on floor 4, but
+-- a floor 2 grave never surfaces on floor 7 - bones drift shallower with
+-- time, never the other way around.
+function Graves.eligibleFor(graves, depth)
+  local eligible = {}
+  if not graves then return eligible end
+  for _, grave in ipairs(graves) do
+    if grave.depth >= depth then eligible[#eligible + 1] = grave end
+  end
+  return eligible
+end
+
+-- The inert floorItem a builder drops for a rolled grave: visibly a grave
+-- from the moment it is seen (no disguise to unmask), carrying just enough
+-- of the fallen's own data for Graves.reveal to build their shade later.
+function Graves.floorItem(grave)
+  return {
+    kind = "grave", grave = true, name = "a weathered grave marker", glyph = "b",
+    graveClass = grave.className, graveGold = grave.gold, graveEssence = grave.essence,
+  }
+end
+
+-- The hostile shade a grave marker becomes the instant it is disturbed:
+-- hp and attack both scale with the wealth it is guarding, capped so even
+-- the richest grave never spawns something the player cannot fight back
+-- against. Mirrors Mimics.reveal's shape (a fresh monster entity, tagged so
+-- awardKill and corpses.lua both know to treat it specially).
+function Graves.reveal(id, x, y, ground)
+  local gold = ground.graveGold or 0
+  local essence = ground.graveEssence or 0
+  local wealth = gold + essence * 2
+  local bonusHp = math.min(20, wealth // 8)
+  local bonusAttack = math.min(6, wealth // 30)
+  local entity = Entity.new({
+    id = id, x = x, y = y,
+    glyph = "G", name = "vengeful shade", kind = "monster",
+    species = "shade", ai = "chase",
+    hp = 10 + bonusHp, maxHp = 10 + bonusHp,
+    attack = 4 + bonusAttack, defense = 1, speed = 105,
+  })
+  entity.cooldown = 0
+  entity.faction = Factions.UNDEAD
+  entity.grave = true
+  entity.graveClass = ground.graveClass
+  entity.graveGold = gold
+  entity.graveEssence = essence
+  return entity
+end
+
+-- Flat xp reward for felling a revealed shade - kept separate from
+-- Monsters.xpFor exactly like Mimics.xpFor, since a shade is never a
+-- member of the wild bestiary Monsters.forDepth draws its per-floor
+-- population from.
+function Graves.xpFor()
+  return 12
+end
+
+-- What a felled shade actually leaves behind: half the gold and a third of
+-- the essence the fallen was carrying at the moment of death - the rest is
+-- gone for good, so a grave is always a net loss across the two runs it
+-- touches, never a way to launder wealth forward.
+function Graves.lootFor(entity)
+  local gold = (entity.graveGold or 0) // 2
+  local essence = (entity.graveEssence or 0) // 3
+  return gold, essence
+end
+
+return Graves

src/hazards.lua

@@ -0,0 +1,114 @@
+-- Timed area hazards that live on the map itself rather than on an entity:
+-- fire and caustic gas. Both linger on their cell, hurt and afflict whoever
+-- ends a turn standing there, and can spread into open neighbouring floor
+-- before burning or blowing themselves out. Fire is doused outright by water.
+-- Hazards are plain data on level.hazards so they serialize like floor items
+-- and traps do, with no special save-format handling.
+
+local Tiles = require("tiles")
+local Status = require("status")
+local Resistances = require("resistances")
+local Conductivity = require("conductivity")
+
+local Hazards = {}
+
+Hazards.FIRE = "fire"
+Hazards.GAS = "gas"
+
+local DIRS = { { 1, 0 }, { -1, 0 }, { 0, 1 }, { 0, -1 } }
+
+-- First hazard occupying (x, y), optionally filtered to a specific kind so
+-- fire and gas can coexist on the same cell without merging into each other.
+function Hazards.at(level, x, y, kind)
+  for _, hz in ipairs(level.hazards) do
+    if hz.x == x and hz.y == y and (not kind or hz.kind == kind) then return hz end
+  end
+  return nil
+end
+
+-- Drops a hazard on (x, y), or refreshes one already there of the same kind
+-- to whichever of the two durations and potencies is stronger. Walls never
+-- catch fire or hold gas.
+function Hazards.spawn(level, x, y, kind, duration, potency)
+  if not level.map:inBounds(x, y) then return nil end
+  if level.map:get(x, y) == Tiles.WALL then return nil end
+  local existing = Hazards.at(level, x, y, kind)
+  if existing then
+    existing.duration = math.max(existing.duration, duration)
+    existing.potency = math.max(existing.potency, potency)
+    return existing
+  end
+  local hz = { x = x, y = y, kind = kind, duration = duration, potency = potency }
+  level.hazards[#level.hazards + 1] = hz
+  return hz
+end
+
+function Hazards.ignite(level, x, y, duration, potency)
+  return Hazards.spawn(level, x, y, Hazards.FIRE, duration or 3, potency or 2)
+end
+
+function Hazards.spawnGas(level, x, y, duration, potency)
+  return Hazards.spawn(level, x, y, Hazards.GAS, duration or 4, potency or 2)
+end
+
+-- Applies whichever hazard occupies entity's current cell, mirroring how
+-- Status.tick afflicts the same actor once per turn. Fire and gas both deal
+-- their potency in direct damage and lay down a fading status effect on top,
+-- so stepping out of the hazard still leaves a lingering burn or sickness.
+function Hazards.afflict(level, entity)
+  local hz = Hazards.at(level, entity.x, entity.y)
+  if not hz then return nil end
+  if hz.kind == Hazards.FIRE then
+    local dealt = Conductivity.applyFire(entity, hz.potency)
+    entity.hp = entity.hp - dealt
+    Status.apply(entity, Status.BURNING, 2, math.max(1, hz.potency // 2))
+    if Conductivity.isWet(entity) then
+      return string.format("flames hiss against %s's soaked skin for %d", entity.name, dealt)
+    end
+    return string.format("flames engulf %s for %d", entity.name, dealt)
+  end
+  local dealt = Resistances.apply(entity, hz.potency, Resistances.POISON)
+  entity.hp = entity.hp - dealt
+  Status.apply(entity, Status.POISON, 2, math.max(1, hz.potency // 2))
+  return string.format("choking fumes sicken %s for %d", entity.name, dealt)
+end
+
+local function canSpreadInto(level, x, y)
+  if not level.map:inBounds(x, y) then return false end
+  local tile = level.map:get(x, y)
+  return Tiles.isWalkable(tile) and tile ~= Tiles.WATER
+end
+
+-- Advances every hazard one environmental step: each has an even chance to
+-- bloom into an open neighbouring cell that isn't already burning or gassed
+-- the same way, water douses fire outright, and every hazard's clock counts
+-- down until it burns or blows itself out. Called once per world round (not
+-- per actor) so a seeded run always spreads identically regardless of how
+-- many actors acted that round.
+function Hazards.step(level, rng)
+  local spawns = {}
+  for _, hz in ipairs(level.hazards) do
+    for _, dir in ipairs(DIRS) do
+      local nx, ny = hz.x + dir[1], hz.y + dir[2]
+      if canSpreadInto(level, nx, ny) and not Hazards.at(level, nx, ny, hz.kind)
+        and rng:chance(1, 2) then
+        spawns[#spawns + 1] = { nx, ny, hz.kind, hz.duration, hz.potency }
+      end
+    end
+  end
+  for _, s in ipairs(spawns) do
+    Hazards.spawn(level, s[1], s[2], s[3], s[4], s[5])
+  end
+
+  local kept = {}
+  for _, hz in ipairs(level.hazards) do
+    local doused = hz.kind == Hazards.FIRE and level.map:get(hz.x, hz.y) == Tiles.WATER
+    hz.duration = hz.duration - 1
+    if hz.duration > 0 and not doused then
+      kept[#kept + 1] = hz
+    end
+  end
+  level.hazards = kept
+end
+
+return Hazards

src/horde.lua

@@ -0,0 +1,244 @@
+-- Horde Arena: an optional survival trial layered onto an existing run,
+-- entirely separate from the depth-descent dungeon (dungeon.lua/builder.lua
+-- never run for it - Game:startHorde builds one closed Level directly, see
+-- Horde.buildArena) yet it still runs through every existing turn system
+-- untouched: scheduler.lua, ai.lua and combat.lua all just see a Level like
+-- any other, since Level.new already defaults every collection an arena has
+-- no use for (shrines, nodes, traps, quest boards...) to an empty table.
+-- What makes it a *horde* rather than one more static floor is Horde.tick,
+-- wired into Game:endPlayerTurn behind a game.horde check: the instant
+-- every monster the current wave placed is dead, it banks a reward, heals a
+-- slice of damage back, and throws the next wave in immediately - there is
+-- never a turn where the arena stands empty. A wave's difficulty is driven
+-- by the same Monsters.forDepth/Elites.maybePromote a real floor already
+-- uses, just fed the wave number as if it were depth, so it never plateaus:
+-- long past the point every species has unlocked, waves just keep growing
+-- larger and rolling elites more often, exactly as if still descending.
+--
+-- Scope: a fresh Game.new never has a game.horde field at all, exactly like
+-- game.nemesis before a nemesis has ever spawned. Because the arena level
+-- lives outside self.dungeon entirely, Game:toData/fromData snapshot both
+-- game.horde and the arena's own Level separately (hordeLevel) so a save
+-- taken mid-arena resumes the exact wave in progress rather than silently
+-- dropping the player back onto the ordinary floor the arena replaced.
+
+local Map = require("map")
+local Tiles = require("tiles")
+local Connect = require("gen.connect")
+local Monsters = require("monsters")
+local Elites = require("elites")
+local Stealth = require("stealth")
+
+local Horde = {}
+
+Horde.WIDTH = 19
+Horde.HEIGHT = 13
+Horde.PILLAR_NUMERATOR = 1
+Horde.PILLAR_DENOMINATOR = 9
+
+-- Chebyshev radius around each corner anchor left pillar-free by
+-- Horde.buildArena, and the radius Horde.spawnPoints itself searches within
+-- of the very same anchors - the two have to agree, or a spawn queue built
+-- wider than the guaranteed-clear zone could try to place a monster on a
+-- cell that turned out to be a pillar.
+Horde.SPAWN_CLEARANCE = 2
+
+Horde.BASE_COUNT = 3
+Horde.COUNT_PER_WAVE = 1
+Horde.MAX_COUNT = 12
+
+Horde.REST_HEAL = 4
+Horde.ESSENCE_PER_WAVE = 5
+
+local function chebyshev(ax, ay, bx, by)
+  return math.max(math.abs(ax - bx), math.abs(ay - by))
+end
+
+-- Fixed corner anchors, inset one cell from the border wall so they are
+-- never the border itself and always inside the interior floor Horde.buildArena
+-- carves - plain open floor by construction, regardless of anything rolled
+-- on the rng that built the rest of the arena.
+function Horde.spawnAnchors(width, height)
+  return {
+    { x = 2, y = 2 }, { x = width - 1, y = 2 },
+    { x = 2, y = height - 1 }, { x = width - 1, y = height - 1 },
+  }
+end
+
+-- The deterministic placement queue Horde.spawnWave fills wave by wave:
+-- every walkable cell within Horde.SPAWN_CLEARANCE of any anchor, round-
+-- robin across the four anchors (first cell of each, then second cell of
+-- each...) rather than anchor-by-anchor, so even a small wave arrives from
+-- more than one direction instead of clumping in a single corner. Each
+-- underlying map cell can only ever claim one slot in the queue, even if
+-- two anchors' clearance zones happened to overlap.
+function Horde.spawnPoints(map)
+  local anchors = Horde.spawnAnchors(map.width, map.height)
+  local perAnchor, claimed = {}, {}
+  for _, anchor in ipairs(anchors) do
+    local cells = {}
+    for y = anchor.y - Horde.SPAWN_CLEARANCE, anchor.y + Horde.SPAWN_CLEARANCE do
+      for x = anchor.x - Horde.SPAWN_CLEARANCE, anchor.x + Horde.SPAWN_CLEARANCE do
+        local idx = map:inBounds(x, y) and map:index(x, y)
+        if idx and not claimed[idx] and map:isWalkable(x, y) then
+          claimed[idx] = true
+          cells[#cells + 1] = { x = x, y = y }
+        end
+      end
+    end
+    perAnchor[#perAnchor + 1] = cells
+  end
+  local points = {}
+  local i, more = 1, true
+  while more do
+    more = false
+    for _, cells in ipairs(perAnchor) do
+      if cells[i] then
+        points[#points + 1] = cells[i]
+        more = true
+      end
+    end
+    i = i + 1
+  end
+  return points
+end
+
+-- One fully-enclosed arena: a rectangle of floor ringed by wall, its
+-- interior sparsely sown with single-tile pillars for cover - except within
+-- Horde.SPAWN_CLEARANCE of any corner anchor, and the centre cell (the
+-- player's own start, see Game:startHorde), both deliberately left clear
+-- regardless of what the pillar pass would otherwise roll there.
+-- Connect.ensure runs last, exactly like every generator gen.init already
+-- dispatches to, so a pillar can never wall off a pocket of floor even
+-- though placement itself never checks for that. Returns the map plus the
+-- centre cell, since Game:startHorde needs it for the player's own start.
+function Horde.buildArena(rng, width, height)
+  width = width or Horde.WIDTH
+  height = height or Horde.HEIGHT
+  local map = Map.new(width, height)
+  for y = 2, height - 1 do
+    for x = 2, width - 1 do
+      map:set(x, y, Tiles.FLOOR)
+    end
+  end
+  local anchors = Horde.spawnAnchors(width, height)
+  local cx, cy = width // 2 + 1, height // 2 + 1
+  for y = 2, height - 1 do
+    for x = 2, width - 1 do
+      local clear = x == cx and y == cy
+      if not clear then
+        for _, anchor in ipairs(anchors) do
+          if chebyshev(x, y, anchor.x, anchor.y) <= Horde.SPAWN_CLEARANCE then
+            clear = true
+            break
+          end
+        end
+      end
+      if not clear and rng:chance(Horde.PILLAR_NUMERATOR, Horde.PILLAR_DENOMINATOR) then
+        map:set(x, y, Tiles.WALL)
+      end
+    end
+  end
+  Connect.ensure(map, rng)
+  return map, cx, cy
+end
+
+function Horde.newState()
+  return { wave = 0 }
+end
+
+function Horde.depthFor(wave)
+  return wave
+end
+
+function Horde.countFor(wave)
+  local count = Horde.BASE_COUNT + (wave - 1) * Horde.COUNT_PER_WAVE
+  if count > Horde.MAX_COUNT then count = Horde.MAX_COUNT end
+  return count
+end
+
+function Horde.essenceFor(wave)
+  return wave * Horde.ESSENCE_PER_WAVE
+end
+
+-- Species eligible for wave `wave`, drawn from Monsters.forDepth at
+-- Horde.depthFor(wave) exactly like a real floor's population, minus the
+-- passive vend-behaviour shopkeeper - a wave the player can never provoke
+-- into fighting back would leave Horde.cleared permanently false.
+function Horde.pool(wave)
+  local eligible = {}
+  for _, spec in ipairs(Monsters.forDepth(Horde.depthFor(wave))) do
+    if spec.ai ~= "vend" then eligible[#eligible + 1] = spec end
+  end
+  return eligible
+end
+
+-- True once every hostile monster the arena has ever placed is dead -
+-- vacuously true against a still-empty arena too, which is exactly what
+-- lets Horde.tick reuse the same check to bootstrap wave 1 as it does to
+-- clear every wave after it (see Horde.tick's own comment). Filtered to
+-- entity.kind == "monster", the same "hostile" tag every other module
+-- (companions.lua/mercenaries.lua/reanimation.lua/abilities.lua...) uses:
+-- Game:startHorde can now carry a bonded companion/hireling/thrall into the
+-- arena, and an ally that never dies to the wave itself would otherwise
+-- keep this permanently false, freezing the arena on wave 0 forever.
+function Horde.cleared(level)
+  for _, entity in ipairs(level.entities) do
+    if entity.kind == "monster" and entity:isAlive() then return false end
+  end
+  return true
+end
+
+-- Populates `game.level` with wave `wave`'s monsters, drawn from
+-- Horde.pool and placed one to a cell along Horde.spawnPoints's queue -
+-- never doubling two monsters onto the same cell, the one-entity-per-cell
+-- invariant every other spawn path in game.lua already relies on. Every
+-- spawn is already hunting, exactly like Game:spawnMinion's own summons -
+-- an arena has no stealth approach to sneak past. Returns the spawned
+-- entities.
+function Horde.spawnWave(game, wave)
+  local level = game.level
+  local points = Horde.spawnPoints(level.map)
+  local pool = Horde.pool(wave)
+  local count = math.min(Horde.countFor(wave), #points)
+  local depth = Horde.depthFor(wave)
+  local spawned = {}
+  for i = 1, count do
+    local point = points[i]
+    local spec = game.rng:pick(pool)
+    local entity = Monsters.create(spec, game:nextMonsterId(), point.x, point.y, depth)
+    entity.awareness = Stealth.HUNTING
+    Elites.maybePromote(game.rng, entity, depth)
+    level.entities[#level.entities + 1] = entity
+    spawned[#spawned + 1] = entity
+  end
+  return spawned
+end
+
+-- Advances horde state by one player turn, called from Game:endPlayerTurn
+-- behind a `game.horde` check. A no-op while the current wave still has a
+-- living monster in it; the instant it does not - including the very first
+-- call, against the still-empty arena Game:startHorde just built, since
+-- Horde.cleared reads that the same way as a genuinely finished wave - it
+-- banks Horde.essenceFor(wave) essence (zero the first time, wave still
+-- being 0), heals Horde.REST_HEAL, advances the wave counter, and spawns
+-- the new wave outright, so the arena is never left standing empty for
+-- even a single turn. Returns a log line, or nil when nothing happened.
+function Horde.tick(game)
+  local horde = game.horde
+  if not horde then return nil end
+  if not Horde.cleared(game.level) then return nil end
+  local reward = Horde.essenceFor(horde.wave)
+  if reward > 0 then
+    game.player.essence = game.player.essence + reward
+  end
+  game.player.hp = math.min(game.player.maxHp, game.player.hp + Horde.REST_HEAL)
+  horde.wave = horde.wave + 1
+  Horde.spawnWave(game, horde.wave)
+  if horde.wave == 1 then
+    return "the horde arena falls silent - wave 1 begins"
+  end
+  return string.format("the arena falls silent - wave %d begins (+%d essence)", horde.wave, reward)
+end
+
+return Horde

src/hunger.lua

@@ -0,0 +1,112 @@
+-- Named bands layered over the player's raw satiation counter, the same
+-- shape sanity.lua already gives its own slow-moving meter: a plain number
+-- that Game:hungerTorchTick drains by one every round (untouched here),
+-- classified into FED/HUNGRY/WEAK/STARVING tiers that a caller reads back
+-- instead of re-deriving the cutoffs itself. Falling into WEAK or worse
+-- costs real attack and defense - wired into entity.lua's effectiveAttack/
+-- effectiveDefense alongside Sanity's own penalty, so a gaunt fighter hits
+-- and blocks softer without combat.lua needing to know hunger exists at
+-- all - and blocks the passive mending hungerTorchTick already grants from
+-- a worn ring, an ironclad set or consecrated ground: a starving adventurer
+-- can still down a potion, just not coast on a ring of regeneration while
+-- fading. STARVING alone keeps hungerTorchTick's own flat hp drain, exactly
+-- as before.
+--
+-- Eating is the mirror case: Hunger.eat folds fresh nutrition into the same
+-- counter, capped at Hunger.CAP, but food eaten while already at that cap
+-- is entirely wasted and leaves the diner Status.SLOW for a few turns - the
+-- same overfull stumble a real glutton earns, reusing a status the engine
+-- already ticks, serializes and renders with no special handling of its own.
+
+local Status = require("status")
+
+local Hunger = {}
+
+Hunger.FED = "fed"
+Hunger.HUNGRY = "hungry"
+Hunger.WEAK = "weak"
+Hunger.STARVING = "starving"
+
+-- Starting ration for a fresh game (Game.new) and the ceiling Hunger.eat
+-- refuses to bank past. Comfortably above START so a couple of found
+-- rations can stack up before a long dive, without letting the pool grow
+-- without bound.
+Hunger.START = 1000
+Hunger.CAP = 1200
+
+-- Tier ceilings: a value at or below HUNGRY_MAX but above WEAK_MAX reads as
+-- HUNGRY, and so on downward. 0 itself is always STARVING regardless of
+-- where these ceilings sit.
+Hunger.HUNGRY_MAX = 300
+Hunger.WEAK_MAX = 100
+
+Hunger.BLOAT_DURATION = 4
+
+local ATTACK_PENALTY = {
+  [Hunger.FED] = 0, [Hunger.HUNGRY] = 0, [Hunger.WEAK] = -2, [Hunger.STARVING] = -4,
+}
+local DEFENSE_PENALTY = {
+  [Hunger.FED] = 0, [Hunger.HUNGRY] = 0, [Hunger.WEAK] = -1, [Hunger.STARVING] = -3,
+}
+
+-- A fresh entity - or a monster, which never accrues hunger of its own
+-- since nothing ever calls Hunger.tick for one - reads as fully fed.
+function Hunger.current(entity)
+  return entity.satiation or Hunger.CAP
+end
+
+function Hunger.tierOf(entity)
+  local value = Hunger.current(entity)
+  if value <= 0 then return Hunger.STARVING end
+  if value <= Hunger.WEAK_MAX then return Hunger.WEAK end
+  if value <= Hunger.HUNGRY_MAX then return Hunger.HUNGRY end
+  return Hunger.FED
+end
+
+function Hunger.attackPenalty(entity)
+  return ATTACK_PENALTY[Hunger.tierOf(entity)]
+end
+
+function Hunger.defensePenalty(entity)
+  return DEFENSE_PENALTY[Hunger.tierOf(entity)]
+end
+
+-- WEAK or worse blocks the passive regen hungerTorchTick otherwise grants
+-- from a ring, a set bonus or friendly weather - a fading body has nothing
+-- left over to spend on mending.
+function Hunger.suppressesRegen(entity)
+  local tier = Hunger.tierOf(entity)
+  return tier == Hunger.WEAK or tier == Hunger.STARVING
+end
+
+-- One round of drain. Returns a log line only when the tier actually
+-- changes, except STARVING which - matching the flat drain this replaces -
+-- reports and bites for 1 hp every single round it holds, not just on the
+-- turn it is first reached.
+function Hunger.tick(entity)
+  local before = Hunger.tierOf(entity)
+  entity.satiation = math.max(0, Hunger.current(entity) - 1)
+  local after = Hunger.tierOf(entity)
+  if after == Hunger.STARVING then
+    entity.hp = entity.hp - 1
+    return "you are starving"
+  end
+  if after ~= before then
+    return "you feel " .. after
+  end
+  return nil
+end
+
+-- Feeds `nutrition` in, clamped at Hunger.CAP. Returns true when the diner
+-- was already at the cap - all of it wasted, and left Status.SLOW for
+-- Hunger.BLOAT_DURATION turns - or false for an ordinary meal that landed.
+function Hunger.eat(entity, nutrition)
+  local wasFull = Hunger.current(entity) >= Hunger.CAP
+  entity.satiation = math.min(Hunger.CAP, Hunger.current(entity) + nutrition)
+  if wasFull then
+    Status.apply(entity, Status.SLOW, Hunger.BLOAT_DURATION, 1)
+  end
+  return wasFull
+end
+
+return Hunger

src/identify.lua

@@ -8,7 +8,7 @@ local Items = require("items")
 local Identify = {}
 
 local potionLooks = {
-  "ruby", "azure", "cloudy", "fizzy", "smoky", "golden", "murky", "viscous",
+  "ruby", "azure", "cloudy", "fizzy", "smoky", "golden", "murky", "viscous", "inky", "frothy",
 }
 local scrollLooks = {
   "XYZZY", "ELBERETH", "ZELGO KAI", "JUYED AWK", "VE FORBRYDERNE",

src/infighting.lua

@@ -0,0 +1,110 @@
+-- Monsters that share no faction bond will occasionally fight each other
+-- outright instead of always beelining for the player. Two rival factions
+-- (see Factions.RIVALRIES) throw down on sight, and any monster carrying
+-- Status.DISCORD - landed by the discord spell, see spells.lua - is
+-- compelled to strike whatever creature stands nearest it, friend or foe,
+-- for the effect's duration. Either way the fight runs through combat.lua
+-- exactly like a player's own attack - same damage formula, same
+-- resistances, same Game:applyEliteOnHit hooks (an elite attacker's
+-- lifesteal or on-hit status rider fires here too, not just against the
+-- player) and the same disease.lua bite chance (a plague-carrier's bite can
+-- infect a rival monster or the player's own companion/hireling/thrall,
+-- not just the player Game:monsterMelee already covers) - so a discorded
+-- troll among goblins is a real threat to both sides, not a scripted
+-- distraction. A plain monster felled this way
+-- still leaves a corpse (scavenging/reanimation can use it) but pays out no
+-- xp, essence, faction standing, or compendium credit - the player didn't
+-- land the blow. A companion, hireling, or thrall killed this way (only
+-- reachable through discord, since none of them carry a faction) dies
+-- exactly as it would to any other monster.
+
+local Combat = require("combat")
+local Status = require("status")
+local Factions = require("factions")
+local Los = require("los")
+local Corpses = require("corpses")
+local Noise = require("noise")
+local Disease = require("disease")
+
+local Infighting = {}
+
+Infighting.SIGHT_RANGE = 8
+
+local function canSee(game, a, b)
+  local cheb = math.max(math.abs(a.x - b.x), math.abs(a.y - b.y))
+  if cheb > Infighting.SIGHT_RANGE then return false end
+  return Los.clear(game.level.map, a.x, a.y, b.x, b.y)
+end
+
+local function isAlly(actor)
+  return actor.kind == "companion" or actor.kind == "hireling" or actor.kind == "thrall"
+end
+
+-- The other living, non-player creature `monster` should be fighting this
+-- turn instead of following its usual Ai.act behaviour, or nil if none
+-- qualifies. A rival-faction monster always qualifies once seen; under
+-- Status.DISCORD, the nearest visible creature of any kind - including the
+-- player's own companion, hireling, or thrall - qualifies too, since
+-- discord scrambles a mind's sense of friend and foe entirely. Ties break
+-- toward the lower entity id, matching Game:nearestAlly's own tie rule.
+function Infighting.target(game, monster)
+  local discorded = Status.has(monster, Status.DISCORD)
+  local best, bestDist = nil, math.huge
+  for _, other in ipairs(game.level.entities) do
+    if other ~= monster and other:isAlive() then
+      local qualifies = discorded or Factions.areRivals(monster.faction, other.faction)
+      if qualifies and canSee(game, monster, other) then
+        local dist = math.max(math.abs(other.x - monster.x), math.abs(other.y - monster.y))
+        if dist < bestDist or (dist == bestDist and other.id < best.id) then
+          best, bestDist = other, dist
+        end
+      end
+    end
+  end
+  return best
+end
+
+-- Resolves one monster-vs-monster hit through the same damage formula any
+-- other attack uses. A defender that falls is swept immediately: a
+-- companion/hireling/thrall dies exactly as game.lua already reports that,
+-- while a plain hostile monster just drops - Corpses.spawn still leaves
+-- remains behind, but no awardKill means no xp/essence/faction/compendium
+-- credit for a kill the player never made.
+function Infighting.strike(game, attacker, defender)
+  local outcome = Combat.attack(attacker, defender)
+  game.log:add(string.format("%s hits %s for %d", attacker.name, defender.name, outcome.damage))
+  game:applyEliteOnHit(attacker, outcome.damage, defender)
+  if attacker.biteDisease and defender:isAlive() and game.rng:chance(1, 4) then
+    if Disease.infect(defender, attacker.biteDisease) then
+      game.log:add(string.format("%s's bite leaves %s feeling ill", attacker.name, defender.name))
+    end
+  end
+  game:emitNoise(attacker.x, attacker.y, Noise.MELEE)
+  if not defender:isAlive() then
+    if isAlly(defender) then
+      game:onActorDeath(defender)
+    else
+      game.log:add(defender.name .. " dies")
+      Corpses.spawn(game.level, defender)
+    end
+  end
+  return outcome
+end
+
+-- Entry point mirroring Abilities.tryAct's contract: returns true when
+-- infighting consumed the monster's turn (attacked an adjacent target or
+-- stepped toward a farther one), false to let the caller fall through to
+-- Ai.act.
+function Infighting.tryAct(game, monster)
+  local target = Infighting.target(game, monster)
+  if not target then return false end
+  local dist = math.max(math.abs(target.x - monster.x), math.abs(target.y - monster.y))
+  if dist <= 1 then
+    Infighting.strike(game, monster, target)
+  else
+    game:stepMonsterToward(monster, target.x, target.y)
+  end
+  return true
+end
+
+return Infighting

src/items.lua

@@ -3,6 +3,8 @@
 -- modifies effective stats when equipped and may carry an affix. Potion and
 -- scroll type catalogs drive the identification system.
 
+local Durability = require("durability")
+
 local Items = {}
 
 Items.POTION = "potion"
@@ -12,14 +14,40 @@ Items.ARMOR = "armor"
 Items.RING = "ring"
 Items.FOOD = "food"
 Items.KEY = "key"
+Items.TOME = "tome"
+Items.AMULET = "amulet"
+Items.BOW = "bow"
+Items.AMMO = "ammo"
+Items.GOLD = "gold"
+Items.GEM = "gem"
+Items.CHARM = "charm"
+Items.KIT = "kit"
+Items.HERB = "herb"
+Items.RUNE = "rune"
+Items.PICK = "pick"
+Items.LOCKPICK = "lockpick"
+Items.CONTRACT = "contract"
+Items.NET = "net"
+Items.RIFTSTONE = "riftstone"
 
 -- Catalogs list every distinct type in a fixed order; identification assigns a
 -- random appearance to each entry, so the order here must stay stable.
+-- New entries append at the end: identify.lua assigns appearances by index
+-- into this list, so inserting anywhere else would reshuffle which look
+-- every earlier, already-loot-tested effect gets for a given seed. There are
+-- exactly as many potionLooks in identify.lua as there are entries here, so
+-- adding one more type here requires a matching look there too.
 Items.potionTypes = {
   { effect = "heal",     name = "potion of healing",   power = 10 },
   { effect = "poison",   name = "potion of poison",    power = 3 },
   { effect = "strength", name = "potion of strength",  power = 0 },
   { effect = "haste",    name = "potion of speed",     power = 0 },
+  { effect = "fortify",  name = "potion of fortification", power = 0 },
+  { effect = "clarity",  name = "potion of clarity",   power = 30 },
+  { effect = "cure",     name = "potion of cleansing", power = 0 },
+  { effect = "confuse",  name = "potion of confusion", power = 0 },
+  { effect = "blind",    name = "potion of blindness", power = 0 },
+  { effect = "levitate", name = "potion of levitation", power = 0 },
 }
 
 Items.scrollTypes = {
@@ -27,6 +55,7 @@ Items.scrollTypes = {
   { effect = "identify",    name = "scroll of identify" },
   { effect = "mapping",     name = "scroll of magic mapping" },
   { effect = "fireball",    name = "scroll of fireball" },
+  { effect = "removecurse", name = "scroll of remove curse" },
 }
 
 function Items.typeId(item)
@@ -54,11 +83,13 @@ function Items.scroll(effect)
 end
 
 function Items.weapon(name, power)
-  return { kind = Items.WEAPON, name = name, glyph = "/", power = power }
+  return { kind = Items.WEAPON, name = name, glyph = "/", power = power,
+    durability = Durability.MAX, maxDurability = Durability.MAX }
 end
 
 function Items.armor(name, power)
-  return { kind = Items.ARMOR, name = name, glyph = "[", power = power }
+  return { kind = Items.ARMOR, name = name, glyph = "[", power = power,
+    durability = Durability.MAX, maxDurability = Durability.MAX }
 end
 
 function Items.ring(name, attack, defense)
@@ -73,26 +104,115 @@ function Items.key(name)
   return { kind = Items.KEY, name = name or "iron key", glyph = "*" }
 end
 
+function Items.tome(spellKey, name)
+  return { kind = Items.TOME, spell = spellKey, name = name or ("tome of " .. spellKey), glyph = "&" }
+end
+
+function Items.amulet(name)
+  return { kind = Items.AMULET, name = name or "Amulet of Warren", glyph = "\"" }
+end
+
+function Items.bow(name, power, range)
+  return { kind = Items.BOW, name = name, glyph = "}", power = power, range = range,
+    durability = Durability.MAX, maxDurability = Durability.MAX }
+end
+
+function Items.ammo(name, count)
+  return { kind = Items.AMMO, name = name or "arrow", glyph = "^", count = count }
+end
+
+function Items.gold(amount)
+  return { kind = Items.GOLD, name = "gold", glyph = "$", amount = amount }
+end
+
+function Items.charm(companionKey, name)
+  return { kind = Items.CHARM, companion = companionKey, name = name or ("charm of the " .. companionKey), glyph = "0" }
+end
+
+function Items.kit(effect)
+  return { kind = Items.KIT, effect = effect, name = effect .. " trap kit", glyph = "t" }
+end
+
+-- A shopkeeper's contract to hire mercenaries.lua's `key` roster entry: paid
+-- for outright at the shop's own price (see shop.lua's CONTRACT branch), so
+-- using it just takes the mercenary on rather than spending any further
+-- gold - unlike a trap kit above, which is free to find but costs nothing
+-- to use either.
+function Items.contract(key, name)
+  return { kind = Items.CONTRACT, hireling = key, name = name or (key .. " contract"), glyph = "P" }
+end
+
+function Items.pick(name, uses)
+  return { kind = Items.PICK, name = name or "miner's pick", glyph = "\\", uses = uses or 20 }
+end
+
+-- A single-use gamble against a locked chest's own lock (see chests.lua's
+-- Chests.pick) - consumed win or lose, unlike the miner's pick above which
+-- wears down over many swings instead of vanishing in one.
+function Items.lockpick(name)
+  return { kind = Items.LOCKPICK, name = name or "lockpick", glyph = ";" }
+end
+
+-- A weighted throwing net (see captives.lua's Captives.resolve): unlike a
+-- thrown weapon above, which is aimed to hurt, a net is aimed to subdue a
+-- battered wild monster alive instead of finishing it off - and is spent
+-- from the inventory whether or not it actually holds, exactly like a
+-- lockpick's own single gamble.
+function Items.net(name)
+  return { kind = Items.NET, name = name or "net", glyph = "o" }
+end
+
+-- Fuel for a single rift crossing (see branches.lua): unlike a key, which
+-- only ever opens the one lock it was cut for, a shard is spent the instant
+-- Game:enterRift first stabilizes a given rift, not on every crossing after -
+-- so carrying more than one only ever matters if the run finds more than one
+-- rift to open.
+function Items.riftstone(name)
+  return { kind = Items.RIFTSTONE, name = name or "rift shard", glyph = "R" }
+end
+
+-- Adds/removes a weapon or armor's power using its own durability-aware
+-- effective power (see durability.lua) rather than its raw `power` field, so
+-- unequipping and later re-equipping an already-broken piece never bakes
+-- power back in for free.
 function Items.equipWeapon(item, entity)
   if entity.weapon then
-    entity.attack = entity.attack - entity.weapon.power
+    entity.attack = entity.attack - Durability.effectivePower(entity.weapon)
     entity.inventory[#entity.inventory + 1] = entity.weapon
   end
   entity.weapon = item
-  entity.attack = entity.attack + item.power
-  return item.power
+  local gained = Durability.effectivePower(item)
+  entity.attack = entity.attack + gained
+  return gained
 end
 
 function Items.equipArmor(item, entity)
   if entity.armor then
-    entity.defense = entity.defense - entity.armor.power
+    entity.defense = entity.defense - Durability.effectivePower(entity.armor)
     entity.inventory[#entity.inventory + 1] = entity.armor
   end
   entity.armor = item
-  entity.defense = entity.defense + item.power
+  local gained = Durability.effectivePower(item)
+  entity.defense = entity.defense + gained
+  return gained
+end
+
+function Items.equipBow(item, entity)
+  if entity.bow then
+    entity.inventory[#entity.inventory + 1] = entity.bow
+  end
+  entity.bow = item
   return item.power
 end
 
+function Items.equipPick(item, entity)
+  if entity.pick then
+    entity.inventory[#entity.inventory + 1] = entity.pick
+  end
+  entity.pick = item
+  return item.uses
+end
+
 function Items.equipRing(item, entity)
   if entity.ring then
     entity.attack = entity.attack - entity.ring.attack
@@ -119,6 +239,10 @@ function Items.use(item, entity)
     return Items.equipArmor(item, entity)
   elseif item.kind == Items.RING then
     return Items.equipRing(item, entity)
+  elseif item.kind == Items.BOW then
+    return Items.equipBow(item, entity)
+  elseif item.kind == Items.PICK then
+    return Items.equipPick(item, entity)
   end
   return 0
 end

src/leaderboard.lua

@@ -0,0 +1,55 @@
+-- Persistent top-N high score table. A run's own numeric score (see
+-- morgue.lua's Morgue.score) only matters across runs if something
+-- remembers it - this is that memory, carried inside meta.lua's own save
+-- file exactly like renown and achievements already are, so a leaderboard
+-- outlives every single run that fed it.
+
+local Leaderboard = {}
+
+Leaderboard.CAPACITY = 10
+
+function Leaderboard.new()
+  return {}
+end
+
+-- Shifts board's tail down to open a gap for `entry` at the first slot
+-- whose current occupant does not outscore it, then drops it there.
+-- Returns the 1-based rank entry lands at, counting past Leaderboard.CAPACITY
+-- when the board is already full - the caller trims that overflow back off.
+local function insertSorted(board, entry)
+  local i = #board + 1
+  while i > 1 and board[i - 1].score < entry.score do
+    board[i] = board[i - 1]
+    i = i - 1
+  end
+  board[i] = entry
+  return i
+end
+
+-- Inserts `entry` (expects at least a numeric .score field) into `board`,
+-- keeping it sorted best-score-first and capped at Leaderboard.CAPACITY.
+-- A run that does not crack the cap is dropped outright rather than kept
+-- around uncounted - a leaderboard only remembers what actually placed.
+-- Returns the rank it landed at, or nil if it did not make the cut.
+function Leaderboard.record(board, entry)
+  local rank = insertSorted(board, entry)
+  while #board > Leaderboard.CAPACITY do
+    table.remove(board)
+  end
+  if rank > Leaderboard.CAPACITY then return nil end
+  return rank
+end
+
+function Leaderboard.top(board, count)
+  local out = {}
+  for i = 1, math.min(count or Leaderboard.CAPACITY, #board) do
+    out[i] = board[i]
+  end
+  return out
+end
+
+function Leaderboard.bestScore(board)
+  return board[1] and board[1].score or 0
+end
+
+return Leaderboard

src/level.lua

@@ -18,6 +18,25 @@ function Level.new(fields)
     floorItems = fields.floorItems or {},
     traps = fields.traps or {},
     lights = fields.lights or {},
+    hazards = fields.hazards or {},
+    shrines = fields.shrines or {},
+    questBoards = fields.questBoards or {},
+    cauldrons = fields.cauldrons or {},
+    nodes = fields.nodes or {},
+    corpses = fields.corpses or {},
+    chests = fields.chests or {},
+    captives = fields.captives or {},
+    vaultLevers = fields.vaultLevers or {},
+    vaultDoors = fields.vaultDoors or {},
+    secretDoors = fields.secretDoors or {},
+    blocks = fields.blocks or {},
+    plates = fields.plates or {},
+    gates = fields.gates or {},
+    prefabVaults = fields.prefabVaults or {},
+    rifts = fields.rifts or {},
+    weather = fields.weather,
+    biome = fields.biome,
+    event = fields.event,
     dark = fields.dark or false,
     explored = fields.explored or {},
     upX = fields.upX, upY = fields.upY,
@@ -34,6 +53,13 @@ function Level:entityAt(x, y)
   return nil
 end
 
+function Level:entityById(id)
+  for _, entity in ipairs(self.entities) do
+    if entity.id == id then return entity end
+  end
+  return nil
+end
+
 function Level:trapAt(x, y)
   for _, trap in ipairs(self.traps) do
     if trap.x == x and trap.y == y then return trap end
@@ -41,6 +67,90 @@ function Level:trapAt(x, y)
   return nil
 end
 
+function Level:shrineAt(x, y)
+  for _, shrine in ipairs(self.shrines) do
+    if shrine.x == x and shrine.y == y then return shrine end
+  end
+  return nil
+end
+
+function Level:questBoardAt(x, y)
+  for _, board in ipairs(self.questBoards) do
+    if board.x == x and board.y == y then return board end
+  end
+  return nil
+end
+
+function Level:cauldronAt(x, y)
+  for _, cauldron in ipairs(self.cauldrons) do
+    if cauldron.x == x and cauldron.y == y then return cauldron end
+  end
+  return nil
+end
+
+function Level:nodeAt(x, y)
+  for _, node in ipairs(self.nodes) do
+    if node.x == x and node.y == y then return node end
+  end
+  return nil
+end
+
+function Level:corpseAt(x, y)
+  for _, corpse in ipairs(self.corpses) do
+    if corpse.x == x and corpse.y == y then return corpse end
+  end
+  return nil
+end
+
+function Level:chestAt(x, y)
+  for _, chest in ipairs(self.chests) do
+    if chest.x == x and chest.y == y then return chest end
+  end
+  return nil
+end
+
+function Level:captiveAt(x, y)
+  for _, captive in ipairs(self.captives) do
+    if captive.x == x and captive.y == y then return captive end
+  end
+  return nil
+end
+
+function Level:vaultLeverAt(x, y)
+  for _, lever in ipairs(self.vaultLevers) do
+    if lever.x == x and lever.y == y then return lever end
+  end
+  return nil
+end
+
+function Level:blockAt(x, y)
+  for _, block in ipairs(self.blocks) do
+    if block.x == x and block.y == y then return block end
+  end
+  return nil
+end
+
+function Level:plateAt(x, y)
+  for _, plate in ipairs(self.plates) do
+    if plate.x == x and plate.y == y then return plate end
+  end
+  return nil
+end
+
+function Level:gateAt(x, y)
+  for _, gate in ipairs(self.gates) do
+    if gate.x == x and gate.y == y then return gate end
+  end
+  return nil
+end
+
+function Level:riftAt(x, y)
+  for _, rift in ipairs(self.rifts) do
+    if rift.x == x and rift.y == y then return rift end
+  end
+  return nil
+end
+
 function Level:itemsAt(x, y)
   local here = {}
   for _, ground in ipairs(self.floorItems) do
@@ -79,6 +189,25 @@ function Level:toData()
     floorItems = self.floorItems,
     traps = self.traps,
     lights = self.lights,
+    hazards = self.hazards,
+    shrines = self.shrines,
+    questBoards = self.questBoards,
+    cauldrons = self.cauldrons,
+    nodes = self.nodes,
+    corpses = self.corpses,
+    chests = self.chests,
+    captives = self.captives,
+    vaultLevers = self.vaultLevers,
+    vaultDoors = self.vaultDoors,
+    secretDoors = self.secretDoors,
+    blocks = self.blocks,
+    plates = self.plates,
+    gates = self.gates,
+    prefabVaults = self.prefabVaults,
+    rifts = self.rifts,
+    weather = self.weather,
+    biome = self.biome,
+    event = self.event,
     dark = self.dark,
     explored = explored,
     upX = self.upX, upY = self.upY,
@@ -103,6 +232,25 @@ function Level.fromData(snapshot)
     floorItems = snapshot.floorItems,
     traps = snapshot.traps,
     lights = snapshot.lights,
+    hazards = snapshot.hazards,
+    shrines = snapshot.shrines,
+    questBoards = snapshot.questBoards,
+    cauldrons = snapshot.cauldrons,
+    nodes = snapshot.nodes,
+    corpses = snapshot.corpses,
+    chests = snapshot.chests,
+    captives = snapshot.captives,
+    vaultLevers = snapshot.vaultLevers,
+    vaultDoors = snapshot.vaultDoors,
+    secretDoors = snapshot.secretDoors,
+    blocks = snapshot.blocks,
+    plates = snapshot.plates,
+    gates = snapshot.gates,
+    prefabVaults = snapshot.prefabVaults,
+    rifts = snapshot.rifts,
+    weather = snapshot.weather,
+    biome = snapshot.biome,
+    event = snapshot.event,
     dark = snapshot.dark,
     explored = explored,
     upX = snapshot.upX, upY = snapshot.upY,

src/mercenaries.lua

@@ -0,0 +1,191 @@
+-- Paid allies hired from a shop's contract rather than bonded for free like
+-- companions.lua's charm or spent raising reanimation.lua's thrall. A
+-- hireling costs nothing further to take on - its hireCost is already paid
+-- the instant the contract itself is bought from a shopkeeper (see
+-- shop.lua's CONTRACT pricing) - but it keeps demanding a wage every
+-- Mercenaries.WAGE_INTERVAL turns (Game:endPlayerTurn) for as long as it
+-- lives. Gold covers it, the hireling's loyalty tops back up; gold falls
+-- short, loyalty takes a hit instead, and a hireling whose loyalty bottoms
+-- out deserts outright. A merely sulking hireling (loyalty still positive
+-- but under Mercenaries.SULKING_THRESHOLD) keeps defending itself if a fight
+-- finds it, but stops chasing distant prey or shadowing the player - the
+-- one place loyalty reaches into combat, and it does so entirely inside
+-- Mercenaries.act rather than through combat.lua or entity.lua, so hiring
+-- one never risks a require cycle with either.
+-- Only one hireling walks at a time, the same one-bond-at-a-time rule
+-- companions.lua keeps for its own charm - but a hireling and a companion
+-- may walk together, since they are bonded through entirely separate
+-- currencies (gold contract vs. found charm) and tagged with distinct kinds.
+-- Hirelings are plain entities on level.entities, exactly like companions
+-- and thralls, so they serialize with no special save-format handling
+-- beyond the two extra fields (wage, loyalty) entity.lua's toData whitelist
+-- adds.
+
+local Entity = require("entity")
+local Combat = require("combat")
+local Los = require("los")
+local Status = require("status")
+local Noise = require("noise")
+
+local Mercenaries = {}
+
+Mercenaries.roster = {
+  { key = "sellsword",  glyph = "w", name = "sellsword",    hp = 24, attack = 6, defense = 2, speed = 100,
+    sight = 6, hireCost = 60, wage = 14 },
+  { key = "skirmisher", glyph = "k", name = "skirmisher",   hp = 15, attack = 5, defense = 1, speed = 115,
+    sight = 8, hireCost = 50, wage = 11 },
+  { key = "medic",      glyph = "m", name = "field medic",  hp = 13, attack = 2, defense = 1, speed = 100,
+    sight = 6, hireCost = 70, wage = 16, heal = 3 },
+}
+
+Mercenaries.byKey = {}
+Mercenaries.order = {}
+for _, spec in ipairs(Mercenaries.roster) do
+  Mercenaries.byKey[spec.key] = spec
+  Mercenaries.order[#Mercenaries.order + 1] = spec.key
+end
+
+Mercenaries.WAGE_INTERVAL = 25
+Mercenaries.START_LOYALTY = 100
+Mercenaries.MAX_LOYALTY = 100
+Mercenaries.LOYALTY_LOSS_UNPAID = 40
+Mercenaries.LOYALTY_GAIN_PAID = 15
+Mercenaries.SULKING_THRESHOLD = 30
+
+local ADJACENT = { { 1, 0 }, { -1, 0 }, { 0, 1 }, { 0, -1 }, { 1, 1 }, { 1, -1 }, { -1, 1 }, { -1, -1 } }
+
+-- Takes `key` into service on a free cell next to the player, retiring any
+-- earlier hireling first. Returns the new hireling, or nil for an unknown
+-- roster key or when every cell around the player is blocked.
+function Mercenaries.hire(game, key)
+  local spec = Mercenaries.byKey[key]
+  if not spec then return nil end
+  for _, other in ipairs(game.level.entities) do
+    if other.kind == "hireling" and other:isAlive() then other.hp = 0 end
+  end
+  game:cleanupDead()
+  local player = game.player
+  for _, dir in ipairs(ADJACENT) do
+    local x, y = player.x + dir[1], player.y + dir[2]
+    if game.level.map:isWalkable(x, y) and not game.level:entityAt(x, y) then
+      local hireling = Entity.new({
+        id = game:nextMonsterId(), x = x, y = y,
+        glyph = spec.glyph, name = spec.name, kind = "hireling",
+        species = key, hp = spec.hp, attack = spec.attack, defense = spec.defense, speed = spec.speed,
+      })
+      hireling.wage = spec.wage
+      hireling.loyalty = Mercenaries.START_LOYALTY
+      game.level.entities[#game.level.entities + 1] = hireling
+      return hireling
+    end
+  end
+  return nil
+end
+
+-- Releases the live hireling (if any) with no penalty to either side.
+-- Returns its name for the caller to log, or nil when nobody is under
+-- contract.
+function Mercenaries.dismiss(game)
+  for _, entity in ipairs(game.level.entities) do
+    if entity.kind == "hireling" and entity:isAlive() then
+      local name = entity.name
+      entity.hp = 0
+      game:cleanupDead()
+      return name
+    end
+  end
+  return nil
+end
+
+-- Charges the live hireling's wage, or shorts it: paid tops loyalty back up
+-- (capped at MAX_LOYALTY), unpaid knocks it down by LOYALTY_LOSS_UNPAID and,
+-- once it bottoms out, the hireling deserts outright - removed from the
+-- level exactly like a voluntary dismiss, just for the opposite reason.
+-- Returns a log line, or nil when no hireling is currently in the party to
+-- bill.
+function Mercenaries.payWage(game)
+  local hireling
+  for _, entity in ipairs(game.level.entities) do
+    if entity.kind == "hireling" and entity:isAlive() then hireling = entity end
+  end
+  if not hireling then return nil end
+  if game.player.gold >= hireling.wage then
+    game.player.gold = game.player.gold - hireling.wage
+    hireling.loyalty = math.min(Mercenaries.MAX_LOYALTY, hireling.loyalty + Mercenaries.LOYALTY_GAIN_PAID)
+    return "you pay your " .. hireling.name .. " " .. hireling.wage .. " gold"
+  end
+  hireling.loyalty = hireling.loyalty - Mercenaries.LOYALTY_LOSS_UNPAID
+  if hireling.loyalty <= 0 then
+    hireling.hp = 0
+    game:cleanupDead()
+    return "your " .. hireling.name .. " deserts, unpaid and unwilling to go on"
+  end
+  return "your " .. hireling.name .. " grumbles, unpaid this floor"
+end
+
+local function adjacent(a, b)
+  return math.max(math.abs(a.x - b.x), math.abs(a.y - b.y)) == 1
+end
+
+-- Nearest living monster the hireling can see within its species' sight
+-- radius, ties broken by ascending id for determinism - the same shape
+-- companions.lua's own nearestHostile follows, including its blind clamp
+-- (Game:canSeePlayer's own melee-range fallback for a blinded monster).
+local function nearestHostile(game, hireling)
+  local spec = Mercenaries.byKey[hireling.species]
+  local sight = spec.sight
+  if Status.has(hireling, Status.BLIND) then sight = math.min(sight, 1) end
+  local best, bestDist = nil, math.huge
+  for _, entity in ipairs(game.level.entities) do
+    if entity.kind == "monster" and entity:isAlive() then
+      local dist = math.max(math.abs(entity.x - hireling.x), math.abs(entity.y - hireling.y))
+      if dist <= sight and Los.clear(game.level.map, hireling.x, hireling.y, entity.x, entity.y) then
+        if dist < bestDist or (dist == bestDist and entity.id < best.id) then
+          best, bestDist = entity, dist
+        end
+      end
+    end
+  end
+  return best
+end
+
+-- A field medic mends its employer a little on any turn it does not spend
+-- fighting or sulking - the only roster entry with a passive off-turn
+-- effect, the same shape companions.lua's hearth sprite follows.
+local function tendPlayer(game, hireling)
+  local spec = Mercenaries.byKey[hireling.species]
+  if spec.heal and game.player.hp < game.player.maxHp then
+    game.player.hp = math.min(game.player.maxHp, game.player.hp + spec.heal)
+  end
+end
+
+-- The hireling's full turn: engage the nearest visible monster if one is in
+-- reach regardless of loyalty, but once loyalty has sunk to
+-- SULKING_THRESHOLD or below, stop there - no chasing a target it can see
+-- but not yet reach, no shadowing the player, no tending. A loyal hireling
+-- gets the full three-branch shape companions.act and Reanimation.act both
+-- follow: engage, close in, or stay within a step of the player.
+function Mercenaries.act(game, hireling)
+  if game:allyActsConfused(hireling) then return end
+  local target = nearestHostile(game, hireling)
+  if target and adjacent(hireling, target) then
+    local outcome = Combat.attack(hireling, target)
+    game.log:add(string.format("your %s hits %s for %d", hireling.name, target.name, outcome.damage))
+    game:emitNoise(hireling.x, hireling.y, Noise.MELEE)
+    if outcome.killed then game:awardKill(target) end
+    return
+  end
+  if hireling.loyalty <= Mercenaries.SULKING_THRESHOLD then
+    return
+  end
+  if target then
+    game:stepMonsterToward(hireling, target.x, target.y)
+    return
+  end
+  tendPlayer(game, hireling)
+  if not adjacent(hireling, game.player) and not (hireling.x == game.player.x and hireling.y == game.player.y) then
+    game:stepMonsterToward(hireling, game.player.x, game.player.y)
+  end
+end
+
+return Mercenaries

src/meta.lua

@@ -0,0 +1,200 @@
+-- Progression that survives a single run: a "renown" currency banked when a
+-- run ends (in death or victory), scored from that run's own tally, plus
+-- achievements unlocked once a run's tally crosses a fixed threshold and
+-- permanent perks bought with banked renown. Meta state lives in its own
+-- save file (see warren.lua's --meta flag), entirely separate from a
+-- mid-run save (serialize.lua/game.lua toData) - a run ending in death still
+-- destroys that run's save, but its renown and any newly met achievement
+-- persist into the next one.
+--
+-- A perk is applied once, in Game.new, before options.class runs (see
+-- Meta.applyAll's caller) so a class delta always lands on top of whatever a
+-- perk already raised - the same ordering classes.lua itself relies on for
+-- its own one-time deltas.
+
+local SaveGame = require("savegame")
+local Ascension = require("ascension")
+local Streaks = require("streaks")
+
+local Meta = {}
+
+-- Real feature history, oldest first: graves and the leaderboard arrived
+-- after the original renown/achievements/perks core, and runHistory (for
+-- Streaks) after that - so a meta file written before either feature landed
+-- is missing those fields, not just hypothetically but in practice for any
+-- save from before this module tracked them.
+local MetaSave = SaveGame.new({
+  [1] = function(data)
+    data.graves = data.graves or {}
+    data.leaderboard = data.leaderboard or {}
+    return data
+  end,
+  [2] = function(data)
+    data.runHistory = data.runHistory or {}
+    return data
+  end,
+})
+
+Meta.PERKS = {
+  { key = "vigor", name = "Vigor", cost = 30, apply = function(player)
+      player.maxHp = player.maxHp + 5
+      player.hp = player.hp + 5
+    end },
+  { key = "purse", name = "Deep Pockets", cost = 20, apply = function(player)
+      player.gold = player.gold + 25
+    end },
+  { key = "focus", name = "Arcane Focus", cost = 25, apply = function(player)
+      player.maxMana = player.maxMana + 5
+      player.mana = player.mana + 5
+    end },
+  { key = "keeneye", name = "Keen Eye", cost = 40, apply = function(player)
+      player.baseAttack = player.baseAttack + 1
+      player.attack = player.attack + 1
+    end },
+  { key = "tough", name = "Thick Hide", cost = 40, apply = function(player)
+      player.baseDefense = player.baseDefense + 1
+      player.defense = player.defense + 1
+    end },
+  { key = "lightbearer", name = "Lightbearer", cost = 25, apply = function(player)
+      player.light.fuel = player.light.fuel + 200
+      player.light.radius = player.light.radius + 1
+    end },
+}
+
+Meta.byKey = {}
+for _, def in ipairs(Meta.PERKS) do
+  Meta.byKey[def.key] = def
+end
+
+-- Each condition reads a run's own metaStats snapshot (see Game:metaStats):
+-- deepestDepth, kills, bossKills, questsCompleted, artifactsFound,
+-- vaultsOpened, setPiecesFound, chestsOpened, won - plus, for the rare
+-- condition that needs more than a single run's own tally can offer, the
+-- persistent meta state itself, already updated with this very run's own
+-- outcome by the time Meta.recordRun evaluates any of these.
+Meta.ACHIEVEMENTS = {
+  { key = "first_blood", name = "First Blood", condition = function(stats) return stats.kills >= 1 end },
+  { key = "boss_slayer", name = "Boss Slayer", condition = function(stats) return stats.bossKills >= 1 end },
+  { key = "deep_delver", name = "Deep Delver", condition = function(stats) return stats.deepestDepth >= 5 end },
+  { key = "bounty_hunter", name = "Bounty Hunter", condition = function(stats) return stats.questsCompleted >= 3 end },
+  { key = "artificer", name = "Artificer", condition = function(stats) return stats.artifactsFound >= 1 end },
+  { key = "vault_breaker", name = "Vault Breaker", condition = function(stats) return (stats.vaultsOpened or 0) >= 1 end },
+  { key = "set_collector", name = "Set Collector", condition = function(stats) return (stats.setPiecesFound or 0) >= 3 end },
+  { key = "amulet_bearer", name = "Amulet Bearer", condition = function(stats) return stats.won end },
+  { key = "hoarder", name = "Hoarder", condition = function(stats) return (stats.chestsOpened or 0) >= 3 end },
+  -- Needs meta.runHistory (see streaks.lua), already carrying this very run
+  -- as its newest entry - a win right after a loss, not just any win.
+  { key = "comeback", name = "Comeback", condition = function(stats, meta)
+      local h = meta.runHistory
+      return stats.won == true and #h >= 2 and h[#h] == true and h[#h - 1] == false
+    end },
+}
+
+function Meta.new()
+  return {
+    renown = 0, totalRuns = 0, wins = 0, bestDepth = 0,
+    achievements = {}, perks = {}, graves = {}, leaderboard = {}, runHistory = {},
+  }
+end
+
+-- Loads meta state from `path`, or a fresh state if the file does not exist
+-- yet (a player's first run). A file that exists but fails to parse or fails
+-- its checksum is corruption, not a first run - that gets a warning on
+-- stderr rather than silently discarding banked renown and achievements, but
+-- still hands back a fresh state so the caller always has something to play
+-- with. Fields missing on an older-version save default in via MetaSave's
+-- migration chain; fields missing despite matching CURRENT_VERSION (a
+-- hand-edited or partially-written file that still happens to parse and
+-- checksum) default in here as a second line of defense.
+function Meta.load(path)
+  local data, err = MetaSave.load(path)
+  if not data then
+    if err ~= "missing" then
+      io.stderr:write("warning: meta file " .. path .. " is " .. err .. "; starting fresh\n")
+    end
+    return Meta.new()
+  end
+  -- graves, leaderboard and runHistory are not re-defaulted here: MetaSave's
+  -- migration chain above already guarantees them on anything that reaches
+  -- this point. The base fields below predate versioning itself (there is no
+  -- earlier step that could have filled them), so they keep their own
+  -- fallback against a hand-edited or partially-written file that still
+  -- parses and checksums.
+  data.renown = data.renown or 0
+  data.totalRuns = data.totalRuns or 0
+  data.wins = data.wins or 0
+  data.bestDepth = data.bestDepth or 0
+  data.achievements = data.achievements or {}
+  data.perks = data.perks or {}
+  return data
+end
+
+function Meta.save(meta, path)
+  MetaSave.save(path, meta)
+end
+
+-- Renown a single completed run banks, from its own tally alone: depth
+-- reached, bosses felled, bounties resolved, vaults cracked open, set
+-- pieces gathered, chests cracked open, and - far above any of those -
+-- escaping with the Amulet. Any ascension.lua mutator active for the run
+-- (stats.mutators, see Game:metaStats) then tops that base score up by its
+-- own renown bonus percentage, rewarding the extra risk taken on.
+function Meta.renownFor(stats)
+  local total = stats.deepestDepth * 4 + stats.bossKills * 15 + stats.questsCompleted * 8
+    + (stats.vaultsOpened or 0) * 10 + (stats.setPiecesFound or 0) * 3 + (stats.chestsOpened or 0) * 2
+  if stats.won then total = total + 100 end
+  local bonusPercent = Ascension.renownBonusPercent(stats.mutators)
+  if bonusPercent > 0 then
+    total = total + (total * bonusPercent) // 100
+  end
+  return total
+end
+
+-- Folds a finished run's stats into the persistent meta state: banks its
+-- renown, advances the run/win/best-depth tallies, and unlocks any
+-- achievement whose condition the run's tally satisfies for the first time.
+-- Returns the newly unlocked achievement names, in catalog order, so a
+-- caller (warren.lua) can announce them; an achievement already owned from an
+-- earlier run is silently skipped rather than re-announced.
+function Meta.recordRun(meta, stats)
+  meta.totalRuns = meta.totalRuns + 1
+  if stats.won then meta.wins = meta.wins + 1 end
+  if stats.deepestDepth > meta.bestDepth then meta.bestDepth = stats.deepestDepth end
+  meta.renown = meta.renown + Meta.renownFor(stats)
+  Streaks.record(meta.runHistory, stats.won == true)
+  local unlocked = {}
+  for _, ach in ipairs(Meta.ACHIEVEMENTS) do
+    if not meta.achievements[ach.key] and ach.condition(stats, meta) then
+      meta.achievements[ach.key] = true
+      unlocked[#unlocked + 1] = ach.name
+    end
+  end
+  return unlocked
+end
+
+function Meta.isOwned(meta, key)
+  return meta.perks[key] == true
+end
+
+-- Spends renown to permanently unlock perk `key`. Fails without spending
+-- anything given an unknown key, a perk already owned, or too little banked
+-- renown; returns (false, reason) in each case.
+function Meta.purchase(meta, key)
+  local def = Meta.byKey[key]
+  if not def then return false, "no such perk" end
+  if meta.perks[key] then return false, "already owned" end
+  if meta.renown < def.cost then return false, "not enough renown" end
+  meta.renown = meta.renown - def.cost
+  meta.perks[key] = true
+  return true, "unlocked " .. def.name
+end
+
+-- Applies every perk `meta` already owns to a freshly created player, in
+-- catalog order. Meant to run once in Game.new, before any class delta.
+function Meta.applyAll(meta, player)
+  for _, def in ipairs(Meta.PERKS) do
+    if meta.perks[def.key] then def.apply(player) end
+  end
+end
+
+return Meta

src/mimics.lua

@@ -0,0 +1,60 @@
+-- A mimic disguises itself as ordinary loot until a hand reaches for it.
+-- Builder.build drops one as a plain floorItem tagged `mimic = true`,
+-- wearing a random disguise's name and glyph (Mimics.DISGUISES) - utterly
+-- indistinguishable at rest from a real item, since render.lua and
+-- Game:pickupHere both just read an ordinary floorItem's own `.item.glyph`
+-- and `.item.name`, with no idea a given tile might be a trap. The instant
+-- the player steps onto it (Game:triggerMimic, called from pickupHere),
+-- Mimics.reveal builds the real hostile monster underneath, scaled by
+-- depth the same way Monsters.create scales a wild species's hp, and gets
+-- one free ambush swing in (via combat.lua, so it still respects the
+-- player's defense and resistances) before it settles into an ordinary
+-- chase like any other monster on its own turns from then on.
+
+local Entity = require("entity")
+local Factions = require("factions")
+
+local Mimics = {}
+
+Mimics.FACTION = Factions.BEAST
+
+Mimics.DISGUISES = {
+  { name = "a weathered chest", glyph = "=" },
+  { name = "a glinting pile of gold", glyph = "$" },
+  { name = "an ornate tome", glyph = "&" },
+  { name = "a discarded shield", glyph = "[" },
+}
+
+-- The inert floorItem a builder drops: it looks exactly like whichever
+-- disguise it rolled until Game:pickupHere unmasks it.
+function Mimics.floorItem(rng)
+  local disguise = Mimics.DISGUISES[rng:range(1, #Mimics.DISGUISES)]
+  return { kind = "mimic", mimic = true, name = disguise.name, glyph = disguise.glyph }
+end
+
+-- The hostile monster a disguised item becomes the instant it is
+-- disturbed, its hp scaled by depth exactly the way Monsters.create scales
+-- a wild species's own base hp.
+function Mimics.reveal(id, x, y, depth)
+  local bonusHp = depth - 1
+  local entity = Entity.new({
+    id = id, x = x, y = y,
+    glyph = "M", name = "mimic", kind = "monster",
+    species = "mimic", ai = "chase",
+    hp = 12 + bonusHp, maxHp = 12 + bonusHp,
+    attack = 5, defense = 1, speed = 100,
+  })
+  entity.cooldown = 0
+  entity.faction = Mimics.FACTION
+  entity.mimic = true
+  return entity
+end
+
+-- Flat xp reward for felling a revealed mimic - kept separate from
+-- Monsters.xpFor since a mimic is never a member of the wild bestiary
+-- Monsters.forDepth draws its ordinary per-floor population from.
+function Mimics.xpFor()
+  return 10
+end
+
+return Mimics

src/momentum.lua

@@ -0,0 +1,39 @@
+-- A player-only combo meter that rewards sustained melee aggression: every
+-- landed melee swing raises the stack by one, up to a hard cap, and each
+-- stack adds a flat attack bonus that reads live through
+-- Entity:effectiveAttack - the very next swing already hits harder, not
+-- just some future one. Taking a hit from a monster's claw, breath or
+-- ambush snaps the whole stack back to zero outright - unlike a status
+-- effect's timed decay, there is no partial forgiveness, so holding a combo
+-- against several foes at once is a far harder rhythm than a lone duel. An
+-- evaded attack (see skills.lua) never reaches Combat.attack at all, so it
+-- never breaks the stack either - only a blow that actually lands does.
+-- Ranged shots, thrown items and environmental damage (traps, poison,
+-- lava) neither build nor break it: momentum is specifically a melee-vs-
+-- monster reward, not a universal combat buff.
+
+local Momentum = {}
+
+Momentum.MAX_STACKS = 5
+Momentum.BONUS_PER_STACK = 1
+
+function Momentum.stacks(entity)
+  return entity.combo or 0
+end
+
+-- Raises `entity`'s stack by one landed melee hit, capped at MAX_STACKS.
+function Momentum.onMeleeHit(entity)
+  entity.combo = math.min(Momentum.MAX_STACKS, Momentum.stacks(entity) + 1)
+end
+
+-- Snaps the stack back to zero the instant `entity` takes a hit.
+function Momentum.onDamaged(entity)
+  entity.combo = 0
+end
+
+-- The flat attack bonus `entity`'s current stack grants.
+function Momentum.attackBonus(entity)
+  return Momentum.stacks(entity) * Momentum.BONUS_PER_STACK
+end
+
+return Momentum

src/monsters.lua

@@ -4,20 +4,41 @@
 -- depth so lower floors bite harder.
 
 local Entity = require("entity")
+local Factions = require("factions")
+local Disease = require("disease")
 
 local Monsters = {}
 
 Monsters.species = {
-  { key = "rat",     glyph = "r", name = "rat",            hp = 4,  attack = 2, defense = 0, speed = 110, ai = "chase",   minDepth = 1 },
-  { key = "bat",     glyph = "v", name = "cave bat",       hp = 3,  attack = 2, defense = 0, speed = 150, ai = "erratic", minDepth = 1 },
-  { key = "kobold",  glyph = "k", name = "kobold",         hp = 6,  attack = 3, defense = 1, speed = 100, ai = "pack",    minDepth = 1 },
-  { key = "goblin",  glyph = "g", name = "goblin",         hp = 5,  attack = 3, defense = 0, speed = 110, ai = "pack",    minDepth = 2 },
-  { key = "archer",  glyph = "a", name = "skeleton archer", hp = 6, attack = 3, defense = 1, speed = 100, ai = "ranged",  minDepth = 2, range = 5 },
-  { key = "orc",     glyph = "o", name = "orc",            hp = 10, attack = 4, defense = 1, speed = 100, ai = "chase",   minDepth = 3 },
-  { key = "wretch",  glyph = "w", name = "cave wretch",    hp = 8,  attack = 2, defense = 0, speed = 120, ai = "flee",    minDepth = 3 },
-  { key = "troll",   glyph = "T", name = "troll",          hp = 16, attack = 6, defense = 2, speed = 80,  ai = "chase",   minDepth = 4 },
-  { key = "mage",    glyph = "m", name = "dark mage",      hp = 8,  attack = 2, defense = 0, speed = 100, ai = "ranged",  minDepth = 5, range = 6 },
-  { key = "dragon",  glyph = "D", name = "young dragon",   hp = 30, attack = 8, defense = 3, speed = 90,  ai = "ranged",  minDepth = 6, range = 4 },
+  { key = "rat",     glyph = "r", name = "rat",            hp = 4,  attack = 2, defense = 0, speed = 110, ai = "chase",   minDepth = 1, xp = 3, faction = Factions.VERMIN, disease = Disease.PARASITES },
+  { key = "bat",     glyph = "v", name = "cave bat",       hp = 3,  attack = 2, defense = 0, speed = 150, ai = "erratic", minDepth = 1, xp = 3, faction = Factions.VERMIN },
+  { key = "kobold",  glyph = "k", name = "kobold",         hp = 6,  attack = 3, defense = 1, speed = 100, ai = "pack",    minDepth = 1, xp = 5, faction = Factions.GOBLINOID, disease = Disease.PLAGUE },
+  { key = "goblin",  glyph = "g", name = "goblin",         hp = 5,  attack = 3, defense = 0, speed = 110, ai = "pack",    minDepth = 2, xp = 5, faction = Factions.GOBLINOID },
+  { key = "archer",  glyph = "a", name = "skeleton archer", hp = 6, attack = 3, defense = 1, speed = 100, ai = "ranged",  minDepth = 2, range = 5, xp = 6, faction = Factions.UNDEAD },
+  { key = "orc",     glyph = "o", name = "orc",            hp = 10, attack = 4, defense = 1, speed = 100, ai = "chase",   minDepth = 3, xp = 9, faction = Factions.ORCISH },
+  { key = "wretch",  glyph = "w", name = "cave wretch",    hp = 8,  attack = 2, defense = 0, speed = 120, ai = "flee",    minDepth = 3, xp = 6, onDeath = "spores", faction = Factions.BEAST },
+  { key = "troll",   glyph = "T", name = "troll",          hp = 16, attack = 6, defense = 2, speed = 80,  ai = "chase",   minDepth = 4, xp = 15, regen = 3, resist = { fire = "weak" }, faction = Factions.BEAST },
+  { key = "mage",    glyph = "m", name = "dark mage",      hp = 8,  attack = 2, defense = 0, speed = 100, ai = "ranged",  minDepth = 5, range = 6, xp = 12, faction = Factions.CULT },
+  { key = "dragon",  glyph = "D", name = "young dragon",   hp = 30, attack = 8, defense = 3, speed = 90,  ai = "ranged",  minDepth = 6, range = 4, xp = 25, breath = "fire", resist = { fire = "immune", cold = "weak" }, faction = Factions.DRAKE },
+
+  -- Ability bearers: each carries an `ability` tag resolved by abilities.lua's
+  -- tryAct dispatch, which runs before the plain ai.lua behaviour listed here
+  -- and only falls through to it when the ability is on cooldown or has no
+  -- valid target. minDepth is kept at 4+ so these never appear on the shallow
+  -- floors exercised by the fixed-maxDepth win-condition tests.
+  { key = "zombie",     glyph = "z", name = "shambling zombie", hp = 7,  attack = 3, defense = 1, speed = 90,  ai = "chase", minDepth = 4, xp = 5, faction = Factions.UNDEAD, disease = Disease.ROT },
+  { key = "slime",      glyph = "j", name = "gelatinous slime", hp = 10, attack = 2, defense = 0, speed = 90,  ai = "chase", minDepth = 4, xp = 5, ability = "split", faction = Factions.BEAST },
+  { key = "footpad",    glyph = "f", name = "footpad",          hp = 6,  attack = 2, defense = 0, speed = 120, ai = "chase", minDepth = 4, xp = 6, ability = "steal", faction = Factions.BANDIT },
+  { key = "shaman",     glyph = "s", name = "goblin shaman",    hp = 7,  attack = 2, defense = 0, speed = 100, ai = "flee",  minDepth = 4, xp = 9, ability = "curse", faction = Factions.GOBLINOID },
+  { key = "necromancer", glyph = "n", name = "necromancer",     hp = 9,  attack = 2, defense = 0, speed = 95,  ai = "flee",  minDepth = 4, xp = 10, ability = "summon", summonSpecies = "zombie", faction = Factions.CULT },
+  { key = "cleric",     glyph = "c", name = "dark cleric",      hp = 8,  attack = 2, defense = 1, speed = 100, ai = "pack",  minDepth = 5, xp = 9, ability = "heal", faction = Factions.CULT },
+  { key = "chieftain",  glyph = "C", name = "orc chieftain",    hp = 14, attack = 5, defense = 2, speed = 100, ai = "pack",  minDepth = 6, xp = 14, ability = "rally", faction = Factions.GOBLINOID },
+  { key = "banshee",    glyph = "b", name = "banshee",          hp = 7,  attack = 2, defense = 0, speed = 100, ai = "flee",  minDepth = 5, xp = 11, ability = "shriek", faction = Factions.UNDEAD },
+
+  -- Shopkeeper: a passive vendor guarding priced wares (see shop.lua). Its
+  -- "vend" behaviour idles until game.lua flags it hostile after a theft, at
+  -- which point it falls back to a plain chase like any other monster.
+  { key = "shopkeeper", glyph = "h", name = "shopkeeper", hp = 8, attack = 3, defense = 1, speed = 100, ai = "vend", minDepth = 4, xp = 7, faction = Factions.MERCHANT },
 }
 
 Monsters.byKey = {}
@@ -36,9 +57,28 @@ function Monsters.forDepth(depth)
   return eligible
 end
 
+-- Xp reward for felling an entity, looked up by the species key stamped onto
+-- it at creation. Falls back to a flat amount for anything without one.
+function Monsters.xpFor(entity)
+  local spec = Monsters.byKey[entity.species]
+  return spec and spec.xp or 4
+end
+
+-- A fresh copy of a species' innate resist table, never the catalog's own
+-- object: elites.lua's "warded" affix mutates entity.resist in place once
+-- rolled, and a shared reference there would leak that bump onto every
+-- other spawn of the same species for the rest of the process, not just
+-- the one entity actually promoted.
+local function copyResist(resist)
+  if not resist then return nil end
+  local copy = {}
+  for damageType, tier in pairs(resist) do copy[damageType] = tier end
+  return copy
+end
+
 function Monsters.create(spec, id, x, y, depth)
   local bonusHp = depth - 1
-  return Entity.new({
+  local entity = Entity.new({
     id = id,
     x = x, y = y,
     glyph = spec.glyph, name = spec.name, kind = "monster",
@@ -47,6 +87,16 @@ function Monsters.create(spec, id, x, y, depth)
     attack = spec.attack, defense = spec.defense,
     speed = spec.speed, range = spec.range or 0,
   })
+  entity.regen = spec.regen
+  entity.onDeath = spec.onDeath
+  entity.breath = spec.breath
+  entity.ability = spec.ability
+  entity.summonSpecies = spec.summonSpecies
+  entity.cooldown = 0
+  entity.resist = copyResist(spec.resist)
+  entity.faction = spec.faction
+  entity.biteDisease = spec.disease
+  return entity
 end
 
 return Monsters

src/morgue.lua

@@ -0,0 +1,132 @@
+-- End-of-run obituary. Turns a finished game's own stats, gear and message
+-- log into a NetHack-style morgue report plus a single comparable score,
+-- reusing exactly the field names Game:metaStats/graveEntry already expose
+-- so a future stat only has to land there to show up here too.
+
+local Curses = require("curses")
+local Compendium = require("compendium")
+local Titles = require("titles")
+
+local Morgue = {}
+
+Morgue.SCORE_WEIGHTS = {
+  depth = 100, kill = 10, bossKill = 250, quest = 150, artifact = 200,
+  vault = 120, setPiece = 180, chest = 15, playerLevel = 50, win = 1000,
+}
+
+-- A single deterministic number from a Morgue.build report, so two runs
+-- (or a run against its own best-so-far) can be ranked without re-reading
+-- every field by hand.
+function Morgue.score(report)
+  local w = Morgue.SCORE_WEIGHTS
+  local total = report.deepestDepth * w.depth + report.kills * w.kill
+    + report.bossKills * w.bossKill + report.questsCompleted * w.quest
+    + report.artifactsFound * w.artifact + report.vaultsOpened * w.vault
+    + report.setPiecesFound * w.setPiece + report.chestsOpened * w.chest
+    + report.playerLevel * w.playerLevel + report.gold
+  if report.won then total = total + w.win end
+  return total
+end
+
+Morgue.EQUIP_SLOTS = { "weapon", "armor", "ring", "bow" }
+
+-- One line per worn slot, empty-handed slots omitted outright rather than
+-- padded with "(nothing)" - an obituary should read like a eulogy, not a
+-- character sheet.
+function Morgue.equipment(player)
+  local lines = {}
+  for _, slot in ipairs(Morgue.EQUIP_SLOTS) do
+    local item = player[slot]
+    if item then
+      lines[#lines + 1] = slot .. ": " .. Curses.label(item, item.name)
+    end
+  end
+  return lines
+end
+
+-- Every species this compendium has ever seen the player slay, heaviest
+-- kill count first, ties broken by catalog order (Compendium.entries' own
+-- fixed order) rather than name so the listing never depends on whatever
+-- order table.sort happens to leave equal keys in.
+function Morgue.killTally(compendium)
+  local rows = {}
+  for i, entry in ipairs(Compendium.entries(compendium)) do
+    if entry.kills > 0 then
+      rows[#rows + 1] = { key = entry.key, name = entry.name, kills = entry.kills, order = i }
+    end
+  end
+  table.sort(rows, function(a, b)
+    if a.kills ~= b.kills then return a.kills > b.kills end
+    return a.order < b.order
+  end)
+  return rows
+end
+
+-- Gathers everything Morgue.format needs straight off a live or just-ended
+-- game, mirroring Game:metaStats' own field names so the two never drift.
+-- `meta` is optional (see warren.lua's --meta flag) - a meta-free run's
+-- report simply carries no title, exactly like it banks no renown.
+function Morgue.build(game, meta)
+  return {
+    won = game.won,
+    alive = game.player:isAlive(),
+    className = game.player.class or "wanderer",
+    title = meta and Titles.forRenown(meta.renown) or nil,
+    playerLevel = game.player.level,
+    deepestDepth = game.deepestDepth,
+    turn = game.turn,
+    gold = game.player.gold,
+    essence = game.player.essence,
+    kills = game.stats.kills,
+    bossKills = game.stats.bossKills,
+    questsCompleted = game.stats.questsCompleted,
+    artifactsFound = game.stats.artifactsFound,
+    vaultsOpened = game.stats.vaultsOpened,
+    setPiecesFound = game.stats.setPiecesFound,
+    chestsOpened = game.stats.chestsOpened,
+    equipment = Morgue.equipment(game.player),
+    killTally = Morgue.killTally(game.compendium),
+    finalMessages = game.log:recent(5),
+  }
+end
+
+local function outcomeLine(report)
+  if report.won then return "escaped the warren with the Amulet" end
+  if report.alive then return "still drawing breath, for now" end
+  return "died in the dark"
+end
+
+-- Renders `report` (see Morgue.build) as a fixed-shape text obituary:
+-- outcome, vitals, gear, kills, final words, score - always in that order
+-- so two runs diff cleanly against each other.
+function Morgue.format(report)
+  local lines = {}
+  local heading = report.alive and (report.won and "Victorious" or "Wandering") or "Late"
+  if report.title then
+    lines[#lines + 1] = string.format("%s the %s, the %s", heading, report.className, report.title)
+  else
+    lines[#lines + 1] = string.format("%s the %s", heading, report.className)
+  end
+  lines[#lines + 1] = outcomeLine(report)
+  lines[#lines + 1] = string.format("depth %d, turn %d, level %d", report.deepestDepth, report.turn,
+    report.playerLevel)
+  lines[#lines + 1] = string.format("gold %d, essence %d", report.gold, report.essence)
+  if #report.equipment > 0 then
+    lines[#lines + 1] = "equipment:"
+    for _, line in ipairs(report.equipment) do lines[#lines + 1] = "  " .. line end
+  end
+  if #report.killTally > 0 then
+    lines[#lines + 1] = "kills:"
+    for _, row in ipairs(report.killTally) do
+      lines[#lines + 1] = string.format("  %-14s x%d", row.name, row.kills)
+    end
+  end
+  if #report.finalMessages > 0 then
+    lines[#lines + 1] = "final moments:"
+    for _, line in ipairs(report.finalMessages) do lines[#lines + 1] = "  " .. line end
+  end
+  lines[#lines + 1] = string.format("score: %d", Morgue.score(report))
+  return table.concat(lines, "\n") .. "\n"
+end
+
+return Morgue

src/nemesis.lua

@@ -0,0 +1,155 @@
+-- A cross-floor hunter. Every other hostile in the bestiary is confined to
+-- the one floor builder.lua drops it on (level.lua's own header: "revisiting
+-- one restores its exact state, dead monsters and all") - a nemesis is the
+-- single exception. Any ordinary monster actually hunting the player the
+-- moment they take a stairwell has a chance to follow them through it
+-- instead of being left behind; from then on it keeps following, growing
+-- stronger each trip, until the player either kills it or dies first.
+--
+-- Unlike elites.lua's affixed variant (rolled stronger the instant builder.lua
+-- places it) or bosses.lua's fixed per-floor set piece, a nemesis is born
+-- mid-run from a plain wild monster and its escalation is entirely
+-- player-earned: it does not exist at all until a hunt actually happens, and
+-- it only ever grows because the player failed to finish it off before
+-- reaching the stairs. Bosses, mimics, graves, elites and the shopkeeper are
+-- all excluded from ever becoming one - each already has its own dedicated
+-- escalation path, and letting them double up would just be two systems
+-- fighting over the same monster.
+
+local Monsters = require("monsters")
+local Stealth = require("stealth")
+
+local Nemesis = {}
+
+-- Odds a hunting monster actually gives chase down the stairs, rolled once
+-- per descent (Game:nemesisTryEmerge) only while no nemesis is following yet.
+Nemesis.CHANCE_NUMERATOR = 1
+Nemesis.CHANCE_DENOMINATOR = 5
+
+Nemesis.MAX_GRUDGE = 5
+Nemesis.HP_BONUS_PER_GRUDGE = 4
+Nemesis.ATTACK_BONUS_PER_GRUDGE = 1
+
+-- How much of its lost hp a nemesis recovers between the floor it last fought
+-- on and the one it just followed the player onto - capped at full, so a
+-- nemesis engaged over and over never shows up weaker than this floor alone
+-- would explain, but also never becomes unkillable simply by being ignored.
+Nemesis.HEAL_FRACTION_PER_FOLLOW = 0.2
+
+-- One epithet per grudge tier, read by index and clamped to the last entry
+-- once grudge outgrows the list - the name keeps escalating in flavour even
+-- after Nemesis.MAX_GRUDGE stops raising its stats any further.
+Nemesis.EPITHETS = {
+  "the Wounded", "the Relentless", "the Scarred", "the Undying", "the Dreaded",
+}
+
+-- ai tags eligible to actually give chase: a permanent "flee" species (the
+-- cave wretch, the goblin shaman, the necromancer) breaks off the instant it
+-- is adjacent so it would never follow anyone down a stairwell, and the
+-- shopkeeper's "vend" idles unless provoked into a plain chase of its own -
+-- by then it is already just a chaser under a different tag, still excluded
+-- here because Nemesis.isEligible also checks awareness below.
+Nemesis.ELIGIBLE_AI = { chase = true, pack = true, ranged = true, erratic = true, tunnel = true }
+
+-- Whether `monster` could give chase this descent: alive, a plain hostile
+-- under its own self-directed AI, already actively hunting the player (not
+-- dormant, not searching, not merely wandering into the stairwell by
+-- coincidence), and not already spoken for by another escalation system.
+function Nemesis.isEligible(monster)
+  return monster:isAlive()
+    and monster.kind == "monster"
+    and Nemesis.ELIGIBLE_AI[monster.ai] == true
+    and monster.awareness == Stealth.HUNTING
+    and not monster.isBoss
+    and not monster.mimic
+    and not monster.grave
+    and not monster.elite
+    and not monster.nemesis
+end
+
+local function chebyshev(ax, ay, bx, by)
+  return math.max(math.abs(ax - bx), math.abs(ay - by))
+end
+
+-- The eligible hunter standing closest to the player, ties broken by
+-- level.entities order - deterministic without spending any rng draw of its
+-- own, since only whether a nemesis emerges at all needs to be a coin flip.
+function Nemesis.pickHunter(level, player)
+  local best, bestDist
+  for _, monster in ipairs(level.entities) do
+    if Nemesis.isEligible(monster) then
+      local dist = chebyshev(monster.x, monster.y, player.x, player.y)
+      if not best or dist < bestDist then
+        best, bestDist = monster, dist
+      end
+    end
+  end
+  return best
+end
+
+-- The persistent descriptor Game keeps between floors (see game.nemesis) -
+-- not a live entity, just enough to rebuild one, exactly like graves.lua
+-- stores a fallen player's own remnants instead of keeping a live shade
+-- around between runs.
+function Nemesis.beginFrom(monster)
+  return {
+    species = monster.species,
+    grudge = 1,
+    hpFraction = monster.hp / monster.maxHp,
+  }
+end
+
+-- Called every time the nemesis follows the player through a stairwell
+-- without having been killed first: its grudge climbs (capped) and it stews
+-- back toward full health (also capped), so each escape makes the next
+-- encounter both tougher and a little less finished business than before.
+function Nemesis.escalate(pursuit)
+  pursuit.grudge = math.min(Nemesis.MAX_GRUDGE, pursuit.grudge + 1)
+  pursuit.hpFraction = math.min(1, pursuit.hpFraction + Nemesis.HEAL_FRACTION_PER_FOLLOW)
+  return pursuit
+end
+
+function Nemesis.bonusHp(grudge)
+  return grudge * Nemesis.HP_BONUS_PER_GRUDGE
+end
+
+function Nemesis.bonusAttack(grudge)
+  return grudge * Nemesis.ATTACK_BONUS_PER_GRUDGE
+end
+
+-- Flat xp on top of the species' own plain reward (Monsters.xpFor already
+-- applies, since Nemesis.spawn stamps a real species key onto the entity) -
+-- mirrors elites.lua's xpBonus riding on top of the same base reward.
+function Nemesis.xpBonus(grudge)
+  return 10 + grudge * 5
+end
+
+-- Gold the nemesis's hoard finally pays out once it is actually put down,
+-- credited alongside (not instead of) the ordinary awardKill flow.
+function Nemesis.bountyGold(grudge)
+  return 10 * grudge
+end
+
+function Nemesis.nameFor(baseName, grudge)
+  local index = math.min(grudge, #Nemesis.EPITHETS)
+  return baseName .. ", " .. Nemesis.EPITHETS[index]
+end
+
+-- Rebuilds a live entity from `pursuit` at (x, y) on the floor just reached,
+-- depth-scaled exactly like any other freshly created monster of the same
+-- species plus its own escalated bonuses. hpFraction survives the trip so a
+-- nemesis last seen half-dead still shows up half-dead here, healed only by
+-- however much Nemesis.escalate already restored between floors.
+function Nemesis.spawn(pursuit, id, x, y, depth)
+  local spec = Monsters.byKey[pursuit.species]
+  local entity = Monsters.create(spec, id, x, y, depth)
+  entity.maxHp = entity.maxHp + Nemesis.bonusHp(pursuit.grudge)
+  entity.hp = math.max(1, math.floor(entity.maxHp * pursuit.hpFraction))
+  entity.attack = entity.attack + Nemesis.bonusAttack(pursuit.grudge)
+  entity.nemesis = true
+  entity.nemesisGrudge = pursuit.grudge
+  entity.name = Nemesis.nameFor(spec.name, pursuit.grudge)
+  return entity
+end
+
+return Nemesis

src/nodes.lua

@@ -0,0 +1,75 @@
+-- Renewable resource nodes scattered on the map: an ore vein pays out
+-- crafting essence (crafting.lua's forging currency) and a gem seam yields a
+-- raw tier-1 gem outright, both without spending a single turn in combat -
+-- a genuine second income alongside killing monsters (Crafting.essenceFor),
+-- not a strictly better replacement for it. Each node holds a fixed number
+-- of charges before it plays out; a played-out node does not vanish, it goes
+-- fallow and slowly reopens on its own, so a floor already cleared of
+-- monsters still rewards a return visit. Nodes are plain data on
+-- level.nodes, exactly like level.shrines and level.cauldrons, so they
+-- serialize with no special save-format handling.
+
+local Crafting = require("crafting")
+
+local Nodes = {}
+
+Nodes.ORE = "ore"
+Nodes.GEM = "gem"
+
+Nodes.glyphs = { [Nodes.ORE] = "O", [Nodes.GEM] = "M" }
+
+Nodes.MAX_CHARGES = 3
+Nodes.REGEN_TURNS = 40
+Nodes.ORE_YIELD_MIN = 3
+Nodes.ORE_YIELD_MAX = 7
+
+-- A freshly placed node at full charges, never on cooldown. Builder stamps
+-- x/y directly onto the returned table, matching how it stamps every other
+-- floor feature (shrines, cauldrons, vault levers).
+function Nodes.new(kind, element)
+  return { kind = kind, element = element, charges = Nodes.MAX_CHARGES, cooldown = 0 }
+end
+
+function Nodes.isFallow(node)
+  return node.charges <= 0
+end
+
+function Nodes.glyph(node)
+  return Nodes.glyphs[node.kind]
+end
+
+-- Extracts one charge's worth of resource from `node` into `game.player`.
+-- Returns (false, line) without touching the node when it has nothing left
+-- to give, or (true, line) once a charge is spent - dropping the node into
+-- cooldown the instant that spends its last one.
+function Nodes.harvest(game, node)
+  if Nodes.isFallow(node) then
+    return false, "the vein is played out; give it time to reopen"
+  end
+  node.charges = node.charges - 1
+  if node.charges <= 0 then node.cooldown = Nodes.REGEN_TURNS end
+  local player = game.player
+  if node.kind == Nodes.ORE then
+    local amount = math.floor(game.rng:range(Nodes.ORE_YIELD_MIN, Nodes.ORE_YIELD_MAX) * game:essenceMultiplier())
+    player.essence = player.essence + amount
+    return true, string.format("you chip %d essence from the ore vein", amount)
+  end
+  local gem = Crafting.gem(node.element, 1)
+  player.inventory[#player.inventory + 1] = gem
+  return true, "you pry a " .. gem.name .. " loose from the seam"
+end
+
+-- Advances every fallow node's cooldown one world round, exactly like
+-- hazards.step advances fire and gas - called once per round, not per actor,
+-- so a seeded run always reopens a vein on the identical turn regardless of
+-- how many actors acted that round.
+function Nodes.step(level)
+  for _, node in ipairs(level.nodes) do
+    if node.cooldown > 0 then
+      node.cooldown = node.cooldown - 1
+      if node.cooldown <= 0 then node.charges = Nodes.MAX_CHARGES end
+    end
+  end
+end
+
+return Nodes

src/noise.lua

@@ -0,0 +1,74 @@
+-- Sound propagation. Unlike los.lua's straight sightline, a noisy action's
+-- racket bends around corners: it floods outward from its origin through
+-- open, walkable cells only, using the same four-directional adjacency
+-- astar.lua's own pathing already assumes (see its DIRS and game.lua's
+-- MONSTER_DIRS), and fades by exactly one point of loudness for every step
+-- the flood has to take to get there. A closed door or a solid wall stops
+-- it dead - nothing leaks through a wall diagonally the way it might with
+-- an eight-directional flood, so a noise never reaches anywhere a monster
+-- could not actually have walked to investigate it.
+--
+-- The flood itself has no idea what a monster or a player is; it is a pure
+-- function of the map, an origin and a starting loudness. game.lua's
+-- Game:emitNoise is what turns a resulting field into a dormant monster
+-- actually stirring (see stealth.lua's Stealth.hear).
+
+local Noise = {}
+
+local DIRS = { { 1, 0 }, { -1, 0 }, { 0, 1 }, { 0, -1 } }
+
+-- Loudness constants for the actions game.lua wires up to emitNoise, tuned
+-- so a whisper-quiet action (nothing currently that quiet) would decay
+-- within a couple of cells while a pick striking stone carries the length
+-- of a small floor.
+Noise.MELEE = 6
+Noise.RANGED = 6
+Noise.THROW = 5
+Noise.SPELL = 8
+Noise.DIG = 9
+
+-- Floods outward from (x, y) through walkable cells, returning a table
+-- keyed by map:index(nx, ny) -> the loudness still remaining once the sound
+-- has traveled there (loudness itself at the origin, decaying by one per
+-- step, never revisiting a cell at an intensity no better than one already
+-- recorded there). A cell the flood never reaches simply has no entry. The
+-- origin itself need not be walkable - a pick striking solid rock (see
+-- game.lua's Game:dig) is exactly as loud as one striking rubble - only the
+-- cells the flood actually spreads into have to be open for anything to
+-- ever stand in them and hear it.
+function Noise.propagate(map, x, y, loudness)
+  local field = {}
+  if loudness <= 0 or not map:inBounds(x, y) then return field end
+  local startIdx = map:index(x, y)
+  field[startIdx] = loudness
+  local queue = { { x = x, y = y, intensity = loudness } }
+  local head = 1
+  while head <= #queue do
+    local cur = queue[head]
+    head = head + 1
+    if cur.intensity > 0 then
+      local nextIntensity = cur.intensity - 1
+      for _, dir in ipairs(DIRS) do
+        local nx, ny = cur.x + dir[1], cur.y + dir[2]
+        if map:isWalkable(nx, ny) then
+          local idx = map:index(nx, ny)
+          if (field[idx] or -1) < nextIntensity then
+            field[idx] = nextIntensity
+            queue[#queue + 1] = { x = nx, y = ny, intensity = nextIntensity }
+          end
+        end
+      end
+    end
+  end
+  return field
+end
+
+-- Remaining loudness a previously computed field still carries at (x, y),
+-- or 0 for anywhere the flood never reached (including out of bounds, which
+-- map:index would otherwise happily compute an index for).
+function Noise.intensityAt(field, map, x, y)
+  if not map:inBounds(x, y) then return 0 end
+  return field[map:index(x, y)] or 0
+end
+
+return Noise

src/phases.lua

@@ -0,0 +1,91 @@
+-- A boss's second, harder-won escalation beyond bosses.lua's enrage. Enrage
+-- is a single instantaneous stat bump that never costs the boss a turn; a
+-- desperation phase is a two-turn state machine that consumes both turns
+-- outright once the boss is battered all the way down to its catalog
+-- desperateAt threshold:
+--   1. brace  - the boss telegraphs for one full turn, a visible defense
+--      spike (desperateDefenseBonus) warning the player something is coming
+--      without yet hurting anyone.
+--   2. unleash - on its very next turn the boss reverts that defense spike
+--      and detonates a single cataclysm, dealing novaDamage to the player
+--      and to every companion, hireling or thrall still within novaRadius.
+-- The cataclysm fires at most once per boss: novaSpent latches permanently
+-- the moment it lands, so a fight survived past it settles back into the
+-- boss's ordinary ability/ai behaviour (abilities.lua) for good. A boss with
+-- no desperateAt in its catalog entry (none outside bosses.lua today) never
+-- enters this state machine at all.
+--
+-- Bracing and unleashing both consume the boss's entire turn - the caller
+-- (Game:takeMonsterTurn) must skip Stealth.tick, Abilities.tryAct and
+-- Ai.act whenever Phases.tick reports the turn consumed, exactly as it
+-- already skips them all under Status.skipsTurn.
+
+local Bosses = require("bosses")
+
+local Phases = {}
+
+local function chebyshev(ax, ay, bx, by)
+  return math.max(math.abs(ax - bx), math.abs(ay - by))
+end
+
+-- Everyone the cataclysm can reach: the player when in range, plus every
+-- living companion, hireling or thrall within the same radius - the same
+-- three-way ally kind the rest of the engine treats as a single "player's
+-- own side" (see game.lua's isPlayerAlly, infighting.lua, and the noise/
+-- confuse/blind symmetry work across companions.lua/mercenaries.lua/
+-- reanimation.lua). A wild monster caught nearby is never a target - a
+-- boss's desperate gambit is aimed at the party that cornered it, not at
+-- whatever else happens to be on the floor (mirrors Bosses itself only ever
+-- threatening the player's side).
+local function novaTargets(game, monster, radius)
+  local targets = {}
+  if chebyshev(game.player.x, game.player.y, monster.x, monster.y) <= radius then
+    targets[#targets + 1] = game.player
+  end
+  for _, other in ipairs(game.level.entities) do
+    if other:isAlive() and (other.kind == "companion" or other.kind == "hireling" or other.kind == "thrall")
+      and chebyshev(other.x, other.y, monster.x, monster.y) <= radius then
+      targets[#targets + 1] = other
+    end
+  end
+  return targets
+end
+
+-- Called once per boss turn, at the same point Bosses.tryEnrage already
+-- runs in Game:takeMonsterTurn (after status/hazard/regen, before every
+-- other action). Returns (line, consumedTurn); consumedTurn true means the
+-- caller must skip everything else this turn, bracing and unleashing both
+-- being the entire point of the turn they happen on.
+function Phases.tick(game, monster)
+  if not monster.isBoss or not monster:isAlive() then return nil, false end
+  local spec = Bosses.byKey[monster.bossKey]
+  if not spec or not spec.desperateAt then return nil, false end
+
+  if monster.channeling then
+    monster.channeling = false
+    monster.novaSpent = true
+    monster.defense = monster.defense - spec.desperateDefenseBonus
+    monster.baseDefense = monster.baseDefense - spec.desperateDefenseBonus
+    local hit = {}
+    for _, victim in ipairs(novaTargets(game, monster, spec.novaRadius)) do
+      victim.hp = victim.hp - spec.novaDamage
+      hit[#hit + 1] = victim == game.player and "you" or victim.name
+    end
+    if #hit == 0 then
+      return string.format("%s unleashes a cataclysm that finds no one in range", monster.name), true
+    end
+    return string.format("%s unleashes a cataclysm on %s for %d", monster.name,
+      table.concat(hit, ", "), spec.novaDamage), true
+  end
+
+  if monster.novaSpent or monster.desperate then return nil, false end
+  if monster.hp > monster.maxHp * spec.desperateAt then return nil, false end
+
+  monster.desperate = true
+  monster.channeling = true
+  monster.defense = monster.defense + spec.desperateDefenseBonus
+  monster.baseDefense = monster.baseDefense + spec.desperateDefenseBonus
+  return string.format("%s reels and begins channeling a desperate cataclysm", monster.name), true
+end
+
+return Phases

src/polymorph.lua

@@ -0,0 +1,63 @@
+-- Rewrites an entity's very body into a different bestiary species mid-run.
+-- Unlike affixes.lua or runewords.lua, which layer bonuses on top of a fixed
+-- body, a polymorph replaces the body outright: name, glyph, ai behaviour,
+-- attack, defense, speed, resistances, faction and any ability tag all come
+-- from the new species wholesale, the same fields Monsters.create stamps
+-- onto a fresh spawn. Only the current hp fraction survives the swap, so a
+-- polymorph is never a cheap full heal and never an outright kill either.
+-- Mutation happens in place on the entity table already held everywhere
+-- else (the turn scheduler, level.entities, a live nemesis reference), so
+-- nothing needs to re-look-up or re-insert anything after a transform.
+
+local Monsters = require("monsters")
+
+local Polymorph = {}
+
+-- Species a polymorph may land on at `depth`, in Monsters.species order so a
+-- given rng draw is deterministic. Excludes the shopkeeper outright: its
+-- "vend" behaviour idles forever once out of the shop context a polymorphed
+-- body would never occupy, leaving it neither hostile nor useful to anyone.
+function Polymorph.pool(depth)
+  local eligible = {}
+  for _, spec in ipairs(Monsters.species) do
+    if spec.key ~= "shopkeeper" and spec.minDepth <= depth then
+      eligible[#eligible + 1] = spec
+    end
+  end
+  return eligible
+end
+
+-- Transforms `entity` in place into a random species drawn from `pool`,
+-- excluding whatever species it already is so a polymorph always changes
+-- something. Returns the species table it became, or nil (entity untouched)
+-- if `pool` has nothing left to offer once the current species is excluded.
+function Polymorph.transform(entity, rng, pool)
+  local choices = {}
+  for _, spec in ipairs(pool) do
+    if spec.key ~= entity.species then choices[#choices + 1] = spec end
+  end
+  if #choices == 0 then return nil end
+  local spec = choices[rng:range(1, #choices)]
+  local fraction = entity.maxHp > 0 and (entity.hp / entity.maxHp) or 1
+  entity.glyph = spec.glyph
+  entity.name = spec.name
+  entity.species = spec.key
+  entity.ai = spec.ai
+  entity.maxHp = spec.hp
+  entity.hp = math.max(1, math.floor(spec.hp * fraction + 0.5))
+  entity.attack = spec.attack
+  entity.defense = spec.defense
+  entity.speed = spec.speed
+  entity.range = spec.range or 0
+  entity.regen = spec.regen
+  entity.onDeath = spec.onDeath
+  entity.breath = spec.breath
+  entity.ability = spec.ability
+  entity.summonSpecies = spec.summonSpecies
+  entity.cooldown = 0
+  entity.resist = spec.resist
+  entity.faction = spec.faction
+  return spec
+end
+
+return Polymorph

src/proficiency.lua

@@ -0,0 +1,88 @@
+-- Weapon mastery: every melee swing the player lands (Game:playerAttack)
+-- nudges their familiarity with whichever weapon delivered it - or their
+-- bare fists, wielding nothing - forward by one point, keyed by the
+-- weapon's own name so a build's proficiency carries seamlessly from one
+-- identical drop to the next with no separate catalog of weapon
+-- "categories" to keep in sync with builder.lua's loot tables, artifacts.
+-- lua's named weapons, or a set piece's own name. Crossing a rank threshold
+-- grants a small, permanent flat attack bonus with that specific weapon (or
+-- fists) alone, read live by Entity:effectiveAttack exactly like momentum.
+-- lua's combo stacks or sanity.lua's dread penalty - so re-equipping a
+-- weapon already mastered picks the bonus straight back up, but switching
+-- to something unfamiliar drops it until that one is mastered in turn.
+--
+-- Melee reads and writes its own key automatically (Proficiency.keyFor
+-- reads the equipped weapon slot, or Proficiency.UNARMED bare-handed), but
+-- the underlying Proficiency.onHitWith/bonusFor pair takes any explicit key
+-- instead - ranged.lua uses this to track mastery of an equipped bow by its
+-- own name, entirely separate from whatever melee weapon (if any) happens
+-- to be equipped alongside it, since Ranged.fire deliberately deals damage
+-- off baseAttack rather than effectiveAttack (see its own header).
+
+local Proficiency = {}
+
+Proficiency.UNARMED = "fists"
+
+-- Hits needed to cross each mastery rank, and the flat attack bonus that
+-- rank grants from then on. Only the highest rank crossed applies (each is
+-- already the running total, not a stacking delta), but the gap between
+-- ranks widens the deeper it goes, so the later ones are meant to take a
+-- genuinely long, dedicated run with one weapon to ever reach.
+Proficiency.RANKS = {
+  { hits = 15,  bonus = 1 },
+  { hits = 40,  bonus = 2 },
+  { hits = 80,  bonus = 3 },
+  { hits = 150, bonus = 4 },
+}
+
+-- The mastery key `entity` is currently swinging: an equipped weapon's own
+-- name, or Proficiency.UNARMED for bare fists.
+function Proficiency.keyFor(entity)
+  return entity.weapon and entity.weapon.name or Proficiency.UNARMED
+end
+
+function Proficiency.hits(entity, key)
+  return (entity.proficiency and entity.proficiency[key]) or 0
+end
+
+-- Records one more landed hit under an explicit `key`, and returns that key
+-- plus the newly reached rank's bonus the instant a threshold is first
+-- crossed - nil otherwise, so a caller only ever logs a genuine milestone
+-- rather than every single swing or shot.
+function Proficiency.onHitWith(entity, key)
+  entity.proficiency = entity.proficiency or {}
+  local before = entity.proficiency[key] or 0
+  local after = before + 1
+  entity.proficiency[key] = after
+  for _, rank in ipairs(Proficiency.RANKS) do
+    if before < rank.hits and after >= rank.hits then
+      return key, rank.bonus
+    end
+  end
+  return nil
+end
+
+-- The flat attack bonus `entity` currently draws from mastery of `key`
+-- alone - never a total across every weapon it has ever swung or fired, so
+-- switching weapons genuinely costs something.
+function Proficiency.bonusFor(entity, key)
+  local hits = Proficiency.hits(entity, key)
+  local bonus = 0
+  for _, rank in ipairs(Proficiency.RANKS) do
+    if hits >= rank.hits then bonus = rank.bonus end
+  end
+  return bonus
+end
+
+-- Melee's own auto-keyed shorthand over the two generic functions above:
+-- always reads and writes whatever Proficiency.keyFor currently reports for
+-- `entity` (its equipped weapon, or bare fists).
+function Proficiency.onMeleeHit(entity)
+  return Proficiency.onHitWith(entity, Proficiency.keyFor(entity))
+end
+
+function Proficiency.attackBonus(entity)
+  return Proficiency.bonusFor(entity, Proficiency.keyFor(entity))
+end
+
+return Proficiency

src/progression.lua

@@ -0,0 +1,48 @@
+-- Player experience and leveling. Killing a monster grants xp scaled by the
+-- species catalog; once xp clears the threshold for the current level the
+-- player levels up, gaining permanent hp/attack/defense and a full heal-up on
+-- the hp gained. A single large xp grant can trigger several level-ups in a
+-- row, so the gain loops rather than checking once.
+
+local Progression = {}
+
+-- Threshold to advance from `level` to `level + 1`. Linear on purpose: pure
+-- and easy to reason about in tests, unlike an exponential curve.
+function Progression.xpToNext(level)
+  return 20 + (level - 1) * 15
+end
+
+local function hpGain(level)
+  return 4 + level
+end
+
+local function levelUp(player)
+  player.level = player.level + 1
+  local gain = hpGain(player.level)
+  player.maxHp = player.maxHp + gain
+  player.hp = player.hp + gain
+  player.attack = player.attack + 1
+  player.baseAttack = player.baseAttack + 1
+  if player.level % 2 == 0 then
+    player.defense = player.defense + 1
+    player.baseDefense = player.baseDefense + 1
+  end
+  player.skillPoints = (player.skillPoints or 0) + 1
+  player.xp = player.xp - player.xpNext
+  player.xpNext = Progression.xpToNext(player.level)
+  return string.format("you reach level %d", player.level)
+end
+
+-- Applies an xp gain to the player, running as many level-ups as the gain
+-- covers. Returns the log lines produced, in order.
+function Progression.grantXp(player, amount)
+  if amount <= 0 then return {} end
+  player.xp = player.xp + amount
+  local lines = {}
+  while player.xp >= player.xpNext do
+    lines[#lines + 1] = levelUp(player)
+  end
+  return lines
+end
+
+return Progression

src/quests.lua

@@ -0,0 +1,90 @@
+-- Bounty boards scattered through the dungeon from depth two on. Each board
+-- is built with exactly one bounty already written on it (a cull, a hoard or
+-- a depth pact), fixed at generation time from the floor's own rng so a given
+-- (worldSeed, depth) always offers the identical bounty. Standing on an
+-- unclaimed board binds the player to its pact for free (no turn spent, same
+-- as learning a skill); a board only ever grants one bounty in its lifetime,
+-- so re-rolling by revisiting an already-claimed board is not possible. A
+-- bound pact resolves itself the instant its condition is met - no trip back
+-- to the board required - paying out gold, xp and essence in one stroke.
+
+local Monsters = require("monsters")
+
+local Quests = {}
+
+Quests.CULL = "cull"
+Quests.HOARD = "hoard"
+Quests.DEPTH = "depth"
+
+-- Fixed order so a given rng draw always names the same kind.
+Quests.order = { Quests.CULL, Quests.HOARD, Quests.DEPTH }
+
+-- Builds the one bounty a freshly placed board offers on `depth`, clamping any
+-- depth target to `maxDepth` so a pact can never demand the unreachable.
+function Quests.generate(rng, depth, maxDepth)
+  local kind = Quests.order[rng:range(1, #Quests.order)]
+  local bounty = {
+    kind = kind,
+    rewardGold = 15 + depth * 8,
+    rewardXp = 10 + depth * 4,
+  }
+  if kind == Quests.CULL then
+    local eligible = Monsters.forDepth(depth)
+    local spec = eligible[rng:range(1, #eligible)]
+    bounty.species = spec.key
+    bounty.speciesName = spec.name
+    bounty.need = rng:range(2, 4)
+    bounty.have = 0
+  elseif kind == Quests.HOARD then
+    bounty.need = 40 + depth * 20
+  else
+    bounty.need = math.min(depth + rng:range(2, 4), maxDepth)
+  end
+  return bounty
+end
+
+function Quests.describe(bounty)
+  if bounty.kind == Quests.CULL then
+    return string.format("cull %d %s (%d/%d)", bounty.need, bounty.speciesName, bounty.have, bounty.need)
+  elseif bounty.kind == Quests.HOARD then
+    return string.format("amass %d gold", bounty.need)
+  end
+  return string.format("reach depth %d", bounty.need)
+end
+
+-- Binds `player` to `board`'s bounty, provided the player is not already
+-- bound to one and the board has not already been claimed. Returns (true,
+-- line) on success or (false, line) explaining why not.
+function Quests.accept(player, board)
+  if player.quest then
+    return false, "you already hold a bounty"
+  end
+  if board.claimed then
+    return false, "this board's ledger is already spent"
+  end
+  board.claimed = true
+  player.quest = board.quest
+  return true, "you bind yourself to a bounty: " .. Quests.describe(board.quest)
+end
+
+-- Registers a kill toward the player's active cull bounty if the species
+-- matches. A no-op for any other kind, an unrelated species, or no bounty.
+function Quests.registerKill(player, species)
+  local bounty = player.quest
+  if bounty and bounty.kind == Quests.CULL and species == bounty.species and bounty.have < bounty.need then
+    bounty.have = bounty.have + 1
+  end
+end
+
+-- True once `player`'s active bounty (if any) is fulfilled by the current
+-- state: a cull once its tally is met, a hoard once live gold clears its
+-- absolute target, a depth pact once the player has reached it.
+function Quests.resolved(player, depth)
+  local bounty = player.quest
+  if not bounty then return false end
+  if bounty.kind == Quests.CULL then return bounty.have >= bounty.need end
+  if bounty.kind == Quests.HOARD then return player.gold >= bounty.need end
+  return depth >= bounty.need
+end
+
+return Quests

src/ranged.lua

@@ -0,0 +1,73 @@
+-- Player ranged combat via an equipped bow and a stack of arrows carried in
+-- the inventory. Unlike throwing, firing never costs the launcher itself -
+-- only ammunition - so a bow stays equipped shot after shot as long as the
+-- quiver holds out. A loosed arrow lands where the target stood either way,
+-- recoverable exactly like a thrown weapon.
+
+local Los = require("los")
+local Items = require("items")
+local Skills = require("skills")
+local Artifacts = require("artifacts")
+local Resistances = require("resistances")
+local Proficiency = require("proficiency")
+local Durability = require("durability")
+
+local Ranged = {}
+
+-- Inventory index of the first non-empty arrow stack, or nil if the quiver
+-- is dry. Ammo of the same name merges into one stack on pickup, so in
+-- practice there is at most one.
+function Ranged.ammoIndex(entity)
+  for i, item in ipairs(entity.inventory) do
+    if item.kind == Items.AMMO and item.count > 0 then return i end
+  end
+  return nil
+end
+
+function Ranged.canReach(game, x1, y1, x2, y2, range)
+  local dist = math.max(math.abs(x1 - x2), math.abs(y1 - y2))
+  return dist <= range and Los.clear(game.level.map, x1, y1, x2, y2)
+end
+
+-- Looses one arrow from `shooter`'s equipped bow at `target`. Returns (true,
+-- lines) if a shot went out - whatever it did on arrival - or (false, lines)
+-- if it never left the string: no bow readied, no arrows, or no clear shot.
+-- Damage comes from baseAttack rather than effectiveAttack so a melee
+-- weapon's power does not also inflate every arrow; the bow's own power and
+-- the target's armour are what separate a longbow from a sling. Mastery of
+-- that specific bow (see proficiency.lua) still applies on top, since it is
+-- read and recorded explicitly by the bow's own name rather than riding
+-- effectiveAttack's blended total.
+function Ranged.fire(game, shooter, target)
+  local bow = shooter.bow
+  if not bow then return false, { "you have no bow readied" } end
+  if not target or not target:isAlive() then return false, { "no target" } end
+  local ammoIdx = Ranged.ammoIndex(shooter)
+  if not ammoIdx then return false, { "you have no arrows left" } end
+  if not Ranged.canReach(game, shooter.x, shooter.y, target.x, target.y, bow.range) then
+    return false, { "you have no clear shot" }
+  end
+  local ammo = shooter.inventory[ammoIdx]
+  ammo.count = ammo.count - 1
+  if ammo.count <= 0 then table.remove(shooter.inventory, ammoIdx) end
+  local defense = math.max(0, target:effectiveDefense() - Artifacts.bowPierce(shooter))
+  local dealt = shooter.baseAttack + Durability.effectivePower(bow) + Skills.rangedDamageBonus(shooter)
+    + Proficiency.bonusFor(shooter, bow.name) - defense
+  if dealt < 1 then dealt = 1 end
+  dealt = Resistances.apply(target, dealt, Resistances.PHYSICAL)
+  target.hp = target.hp - dealt
+  local lines = { string.format("your %s hits %s for %d", ammo.name, target.name, dealt) }
+  game.level.floorItems[#game.level.floorItems + 1] = {
+    x = target.x, y = target.y, item = { kind = Items.AMMO, name = ammo.name, glyph = ammo.glyph, count = 1 },
+  }
+  local masteredKey, masteredBonus = Proficiency.onHitWith(shooter, bow.name)
+  if masteredKey then
+    lines[#lines + 1] = string.format("you grow more skilled with your %s (+%d attack)", masteredKey, masteredBonus)
+  end
+  local broke = Durability.wearBow(shooter)
+  if broke then lines[#lines + 1] = broke end
+  if not target:isAlive() then game:awardKill(target) end
+  return true, lines
+end
+
+return Ranged

src/reanimation.lua

@@ -0,0 +1,158 @@
+-- Necromancy: consumes a still-fresh corpse underfoot to raise it as a
+-- temporary skeletal thrall that fights beside the player until its
+-- borrowed animation runs out. Unlike companions.lua's charm-bonded ally,
+-- which persists across the whole run once bonded, a thrall is spent the
+-- instant it collapses - reduced to inert bones, nothing left to butcher a
+-- second time - and raising one costs the player a bite of sanity.lua's own
+-- meter, the same currency dread already drains, since bending a corpse
+-- back into motion is exactly the kind of wrongness that meter tracks.
+-- Only one thrall may walk at a time; raising a second dismisses the first
+-- outright, the same one-bond-at-a-time rule companions.lua keeps for its
+-- own charm. Thralls are plain entities on level.entities, exactly like
+-- companions, so they serialize with no special save-format handling
+-- beyond the one extra field (decay) entity.lua's toData whitelist adds.
+
+local Entity = require("entity")
+local Combat = require("combat")
+local Los = require("los")
+local Monsters = require("monsters")
+local Corpses = require("corpses")
+local Status = require("status")
+local Noise = require("noise")
+
+local Reanimation = {}
+
+Reanimation.LIFESPAN = 40
+Reanimation.SANITY_COST = 15
+Reanimation.HP_FRACTION = 0.6
+Reanimation.ATTACK_PENALTY = 1
+Reanimation.SIGHT = 6
+
+local ADJACENT = { { 1, 0 }, { -1, 0 }, { 0, 1 }, { 0, -1 }, { 1, 1 }, { 1, -1 }, { -1, 1 }, { -1, -1 } }
+
+-- Combat numbers for the thrall raised from a corpse of `speciesKey`: a
+-- fraction of the living species' own hp, attack blunted by one point for
+-- fighting with brittle bone instead of flesh, and defense and speed left
+-- exactly as they were - an animated skeleton is exactly as easy or hard to
+-- land a blow on, and exactly as quick underfoot, as the creature it once
+-- was. Falls back to a flat, unremarkable skeleton for any corpse whose
+-- species the bestiary no longer recognises (none today, but a save could
+-- in principle outlive a species removed from a later build).
+local function statsFor(speciesKey)
+  local spec = Monsters.byKey[speciesKey]
+  if not spec then return { hp = 8, attack = 2, defense = 0, speed = 100 } end
+  return {
+    hp = math.max(4, math.floor(spec.hp * Reanimation.HP_FRACTION)),
+    attack = math.max(1, spec.attack - Reanimation.ATTACK_PENALTY),
+    defense = spec.defense,
+    speed = spec.speed,
+  }
+end
+
+-- Raises `corpse` beside the player, retiring any earlier thrall first and
+-- spending the corpse and a bite of sanity outright. Returns the new
+-- thrall, or (nil, line) with nothing changed when the corpse has already
+-- rotted past use, the player's own mind cannot bear the cost, or every
+-- cell around the player is blocked.
+function Reanimation.raise(game, corpse)
+  if Corpses.isRotten(corpse) then
+    return nil, "this corpse has rotted too far to answer the call"
+  end
+  if game.player.sanity < Reanimation.SANITY_COST then
+    return nil, "your grip on your own mind is too frail for this"
+  end
+  local player = game.player
+  local x, y
+  for _, dir in ipairs(ADJACENT) do
+    local cx, cy = player.x + dir[1], player.y + dir[2]
+    if game.level.map:isWalkable(cx, cy) and not game.level:entityAt(cx, cy) then
+      x, y = cx, cy
+      break
+    end
+  end
+  if not x then
+    return nil, "there is nowhere for a thrall to rise"
+  end
+  for _, other in ipairs(game.level.entities) do
+    if other.kind == "thrall" and other:isAlive() then other.hp = 0 end
+  end
+  game:cleanupDead()
+  for i, candidate in ipairs(game.level.corpses) do
+    if candidate == corpse then
+      table.remove(game.level.corpses, i)
+      break
+    end
+  end
+  player.sanity = math.max(0, player.sanity - Reanimation.SANITY_COST)
+  local stats = statsFor(corpse.species)
+  local thrall = Entity.new({
+    id = game:nextMonsterId(), x = x, y = y,
+    glyph = "Z", name = corpse.name .. " thrall", kind = "thrall",
+    species = corpse.species, hp = stats.hp, attack = stats.attack, defense = stats.defense, speed = stats.speed,
+  })
+  thrall.decay = Reanimation.LIFESPAN
+  game.level.entities[#game.level.entities + 1] = thrall
+  return thrall
+end
+
+local function adjacent(a, b)
+  return math.max(math.abs(a.x - b.x), math.abs(a.y - b.y)) == 1
+end
+
+-- Nearest living monster the thrall can see within Reanimation.SIGHT, ties
+-- broken by ascending id for determinism - the same shape companions.lua's
+-- own nearestHostile follows, including its blind clamp (Game:canSeePlayer's
+-- own melee-range fallback for a blinded monster).
+local function nearestHostile(game, thrall)
+  local sight = Reanimation.SIGHT
+  if Status.has(thrall, Status.BLIND) then sight = math.min(sight, 1) end
+  local best, bestDist = nil, math.huge
+  for _, entity in ipairs(game.level.entities) do
+    if entity.kind == "monster" and entity:isAlive() then
+      local dist = math.max(math.abs(entity.x - thrall.x), math.abs(entity.y - thrall.y))
+      if dist <= sight and Los.clear(game.level.map, thrall.x, thrall.y, entity.x, entity.y) then
+        if dist < bestDist or (dist == bestDist and entity.id < best.id) then
+          best, bestDist = entity, dist
+        end
+      end
+    end
+  end
+  return best
+end
+
+-- The thrall's full turn: its borrowed animation runs out by one turn
+-- first, and once it hits zero the thrall collapses back into inert bones
+-- through the very same Game:onActorDeath path a slain one already falls
+-- through - called directly here, exactly like Game:checkTrapFor calls it
+-- directly for a trap kill mid-move, since nothing later in the caller's
+-- own takeMonsterTurn pipeline re-checks aliveness once dispatch returns.
+-- Otherwise it fights whatever hostile it can already reach, closes on one
+-- it can see but not yet reach, or shadows the player - the same
+-- three-branch shape as Companions.act, minus any tending since a thrall
+-- has nothing of its own to spare.
+function Reanimation.act(game, thrall)
+  thrall.decay = thrall.decay - 1
+  if thrall.decay <= 0 then
+    thrall.hp = 0
+    game:onActorDeath(thrall)
+    return
+  end
+  if game:allyActsConfused(thrall) then return end
+  local target = nearestHostile(game, thrall)
+  if target and adjacent(thrall, target) then
+    local outcome = Combat.attack(thrall, target)
+    game.log:add(string.format("your %s claws %s for %d", thrall.name, target.name, outcome.damage))
+    game:emitNoise(thrall.x, thrall.y, Noise.MELEE)
+    if outcome.killed then game:awardKill(target) end
+    return
+  end
+  if target then
+    game:stepMonsterToward(thrall, target.x, target.y)
+    return
+  end
+  if not adjacent(thrall, game.player) and not (thrall.x == game.player.x and thrall.y == game.player.y) then
+    game:stepMonsterToward(thrall, game.player.x, game.player.y)
+  end
+end
+
+return Reanimation

src/render.lua

@@ -4,9 +4,25 @@
 
 local Status = require("status")
 local Identify = require("identify")
+local Hazards = require("hazards")
+local Encumbrance = require("encumbrance")
+local Stealth = require("stealth")
+local Nodes = require("nodes")
+local Sets = require("sets")
+local Curses = require("curses")
+local Momentum = require("momentum")
+local Conductivity = require("conductivity")
+local Sanity = require("sanity")
+local Events = require("events")
+local Proficiency = require("proficiency")
+local Durability = require("durability")
+local Hunger = require("hunger")
+local Disease = require("disease")
 
 local Render = {}
 
+local hazardGlyphs = { [Hazards.FIRE] = "`", [Hazards.GAS] = "," }
+
 local function cell(game, x, y)
   local level = game.level
   local map = level.map
@@ -16,36 +32,118 @@ local function cell(game, x, y)
     if game.player.x == x and game.player.y == y then return "@" end
     local monster = level:entityAt(x, y)
     if monster then return monster.glyph end
+    local hazard = Hazards.at(level, x, y)
+    if hazard then return hazardGlyphs[hazard.kind] end
+    if level:shrineAt(x, y) then return "_" end
+    if level:blockAt(x, y) then return "0" end
+    if level:plateAt(x, y) then return ";" end
+    if level:cauldronAt(x, y) then return "U" end
+    local node = level:nodeAt(x, y)
+    if node then return Nodes.glyph(node) end
+    local board = level:questBoardAt(x, y)
+    if board then return board.claimed and "=" or "&" end
+    if level:corpseAt(x, y) then return "%" end
+    local chest = level:chestAt(x, y)
+    if chest then return chest.opened and "b" or "B" end
+    if level:riftAt(x, y) then return "Q" end
     local here = level:itemsAt(x, y)
     if #here > 0 then return here[1].item.glyph end
   end
   return map:get(x, y)
 end
 
+-- Disease was previously invisible outside the transient log lines
+-- Disease.tick emits (the eruption, a damage tick, an escalation) - once
+-- one of those scrolled off, a player mid-incubation or mid-plague had no
+-- persistent way to check their own affliction at all. Folded into the same
+-- comma-joined tag line as the timed statuses above, since both are
+-- "what's currently afflicting this entity" facts the HUD already exists to
+-- surface.
 local function statusTags(entity)
   local tags = {}
   for _, active in ipairs(entity.statuses) do
     tags[#tags + 1] = active.kind
   end
+  if Disease.isInfected(entity) then
+    local infection = entity.disease
+    local name = Disease.defs[infection.key].name
+    tags[#tags + 1] = Disease.hasErupted(entity)
+      and string.format("%s(stage %d)", name, infection.stage)
+      or string.format("%s(incubating)", name)
+  end
   if #tags == 0 then return "none" end
   return table.concat(tags, ",")
 end
 
+-- How many of the level's living monsters are still asleep, out of the total
+-- - purely informational, so autopilot and other callers never read it.
+local function dormantCount(level)
+  local count = 0
+  for _, entity in ipairs(level.entities) do
+    if entity.kind == "monster" and entity:isAlive() and Stealth.isUnaware(entity) then
+      count = count + 1
+    end
+  end
+  return count
+end
+
+-- Appends a wear indicator to `label` only once `item` has actually taken
+-- damage - broken outright, or merely dinged - leaving a pristine piece's
+-- label exactly as clean as before this module existed.
+local function gearLabel(item, label)
+  if Durability.missing(item) == 0 then return label end
+  if Durability.isBroken(item) then return label .. " (broken)" end
+  return string.format("%s (%d/%d)", label, item.durability, item.maxDurability)
+end
+
 function Render.panel(game)
   local player = game.player
   local level = game.level
-  local weapon = player.weapon and Identify.label(game.identify, player.weapon) or "none"
-  local armor = player.armor and Identify.label(game.identify, player.armor) or "none"
-  local ring = player.ring and player.ring.name or "none"
+  local weapon = player.weapon
+    and gearLabel(player.weapon, Curses.label(player.weapon, Identify.label(game.identify, player.weapon))) or "none"
+  local armor = player.armor
+    and gearLabel(player.armor, Curses.label(player.armor, Identify.label(game.identify, player.armor))) or "none"
+  local ring = player.ring and Curses.label(player.ring, player.ring.name) or "none"
+  local bow = player.bow and gearLabel(player.bow, Curses.label(player.bow, player.bow.name)) or "none"
   local torch = player.light.fuel > 0 and tostring(player.light.fuel) or "spent"
+  local asleep = dormantCount(level)
+  local foes = asleep > 0 and string.format("%d (%d asleep)", #level.entities, asleep)
+    or tostring(#level.entities)
   local lines = {
-    string.format("HP %d/%d  ATK %d  DEF %d  depth %d  turn %d  %s%s",
+    string.format("HP %d/%d  ATK %d  DEF %d  lvl %d  depth %d  turn %d  %s%s%s%s",
       player.hp, player.maxHp, player:effectiveAttack(), player:effectiveDefense(),
-      game.depth, game.turn, level.generator, level.dark and "  dark" or ""),
-    string.format("food %d  torch %s  status %s", player.satiation, torch, statusTags(player)),
-    string.format("weapon %s  armor %s  ring %s  items %d  foes %d",
-      weapon, armor, ring, #player.inventory, #level.entities),
+      player.level, game.depth, game.turn, level.generator, level.dark and "  dark" or "",
+      level.weather and ("  " .. level.weather) or "", game.won and "  WON" or ""),
+    string.format("xp %d/%d  mana %d/%d  food %d  torch %s  gold %d  status %s",
+      player.xp, player.xpNext, player.mana, player.maxMana, player.satiation, torch, player.gold, statusTags(player)),
+    string.format("load %s (%d/%d)",
+      player:encumbranceTier(), Encumbrance.carriedWeight(player), Encumbrance.capacityFor(player)),
+    string.format("weapon %s  armor %s  ring %s  bow %s  items %d  foes %s",
+      weapon, armor, ring, bow, #player.inventory, foes),
   }
+  local activeSets = Sets.activeDescriptions(player)
+  if activeSets then lines[#lines + 1] = "set " .. activeSets end
+  local combo = Momentum.stacks(player)
+  if combo > 0 then lines[#lines + 1] = string.format("combo x%d", combo) end
+  if Conductivity.isWet(player) then lines[#lines + 1] = string.format("wet (%d)", player.wet) end
+  local masteryBonus = Proficiency.attackBonus(player)
+  if masteryBonus > 0 then
+    lines[#lines + 1] = string.format("mastery +%d with %s", masteryBonus, Proficiency.keyFor(player))
+  end
+  local sanityTier = Sanity.tierOf(player)
+  if sanityTier ~= Sanity.COMPOSED then
+    lines[#lines + 1] = string.format("sanity %d/%d (%s)", Sanity.current(player), Sanity.MAX, sanityTier)
+  end
+  local hungerTier = Hunger.tierOf(player)
+  if hungerTier ~= Hunger.FED then
+    lines[#lines + 1] = string.format("hunger %d/%d (%s)", Hunger.current(player), Hunger.CAP, hungerTier)
+  end
+  if level.event then
+    lines[#lines + 1] = string.format("event %s (%d turns left)", level.event.key, level.event.turnsLeft)
+  end
+  if game.ascension and #game.ascension > 0 then
+    lines[#lines + 1] = "ascension " .. table.concat(game.ascension, ",")
+  end
   local last = game.log:last()
   if last then lines[#lines + 1] = "- " .. last end
   return table.concat(lines, "\n")

src/replay.lua

@@ -0,0 +1,62 @@
+-- Re-simulates a run from nothing but its own seed, options and step count
+-- to confirm it actually reproduces a recorded outcome - the same guarantee
+-- rngDeterminism and mapDeterminism already lean on internally, spelled out
+-- here as a standalone check a caller can run against any (seed, options,
+-- steps) triple, e.g. to confirm a regression fix left a known-good seed's
+-- ending untouched, or to flag a leaderboard entry whose recorded report no
+-- longer matches what that seed actually plays out to.
+--
+-- Scope: this replays purely from (seed, options, steps) - it says nothing
+-- about a run that also carried mutable meta.lua state (perks already
+-- owned, a compendium already partway filled), since that state moves
+-- forward with every run and is never itself snapshotted. Call it only for
+-- a plain run, or pass the exact historical options a meta-bearing run
+-- actually started with.
+
+local Game = require("game")
+local Morgue = require("morgue")
+
+local Replay = {}
+
+-- Runs a fresh game for exactly `steps` auto-steps (or until the player
+-- dies first) and returns its final Morgue.build report.
+function Replay.run(seed, options, steps)
+  local game = Game.new(seed, options)
+  for _ = 1, steps do
+    if not game.player:isAlive() then break end
+    game:autoStep()
+  end
+  return Morgue.build(game)
+end
+
+-- Every field Morgue.score actually reads, plus won/alive - deliberately not
+-- equipment/killTally/finalMessages, which are free-form listings a caller
+-- rarely wants compared byte-for-byte.
+Replay.COMPARED_FIELDS = {
+  "won", "alive", "deepestDepth", "turn", "gold", "essence",
+  "kills", "bossKills", "questsCompleted", "artifactsFound",
+  "vaultsOpened", "setPiecesFound", "chestsOpened", "playerLevel",
+}
+
+-- True iff `report` and `replayed` agree on every Replay.COMPARED_FIELDS
+-- entry. Returns (false, field) naming the first mismatch found, in
+-- Replay.COMPARED_FIELDS order, so a caller can say exactly what diverged
+-- rather than just that something did.
+function Replay.matches(report, replayed)
+  for _, field in ipairs(Replay.COMPARED_FIELDS) do
+    if report[field] ~= replayed[field] then return false, field end
+  end
+  return true, nil
+end
+
+-- Re-simulates (seed, options, steps) and checks whether it reproduces
+-- `report` (see Replay.matches). Always returns the score the replay itself
+-- earned, whether or not it matched, so a caller can tell a merely-outdated
+-- record from one whose replay actually played worse.
+function Replay.verify(seed, options, steps, report)
+  local replayed = Replay.run(seed, options, steps)
+  local matches, mismatchField = Replay.matches(report, replayed)
+  return matches, mismatchField, Morgue.score(replayed)
+end
+
+return Replay

src/resistances.lua

@@ -0,0 +1,67 @@
+-- Elemental damage typing. Every hit that lands - melee, a bolt, a thrown
+-- weapon, a hazard tick, a status effect's damage-over-time - is tagged with
+-- one of the types below, and this module decides how much of it actually
+-- gets through. A defender's tier for a type comes from up to two places: its
+-- own base profile (bestiary data, e.g. a dragon's own hide) and whatever it
+-- has equipped (weapon/armor/ring/bow, e.g. a ring of cold resistance). The
+-- single best (most protective) tier across those sources wins - immune beats
+-- resist beats weak beats the normal default - so a found ring can cancel out
+-- an innate vulnerability, but nothing ever stacks two resists into a second
+-- discount or two weaknesses into a bigger penalty.
+
+local Resistances = {}
+
+Resistances.PHYSICAL = "physical"
+Resistances.FIRE = "fire"
+Resistances.COLD = "cold"
+Resistances.POISON = "poison"
+Resistances.LIGHTNING = "lightning"
+Resistances.ARCANE = "arcane"
+
+Resistances.TYPES = {
+  Resistances.PHYSICAL, Resistances.FIRE, Resistances.COLD,
+  Resistances.POISON, Resistances.LIGHTNING, Resistances.ARCANE,
+}
+
+Resistances.IMMUNE = "immune"
+Resistances.RESIST = "resist"
+Resistances.WEAK = "weak"
+Resistances.NORMAL = "normal"
+
+local RANK = { immune = 3, resist = 2, weak = 1, normal = 0 }
+
+-- Slots checked alongside an entity's own `resist` table, in a fixed order so
+-- the result never depends on Lua's unspecified pairs() iteration order.
+local EQUIP_SLOTS = { "weapon", "armor", "ring", "bow" }
+
+local function tierFrom(source, damageType)
+  return source and source.resist and source.resist[damageType]
+end
+
+-- The single tier that governs `damageType` incoming against `entity`, folding
+-- in its own base profile and every equipped slot that carries one.
+function Resistances.tierOf(entity, damageType)
+  local best = tierFrom(entity, damageType) or Resistances.NORMAL
+  for _, slot in ipairs(EQUIP_SLOTS) do
+    local tier = tierFrom(entity[slot], damageType)
+    if tier and RANK[tier] > RANK[best] then
+      best = tier
+    end
+  end
+  return best
+end
+
+-- Scales a already-computed `amount` of `damageType` damage by `entity`'s
+-- tier for that type. Immune drops it to nothing outright rather than merely
+-- halving it, so it can floor damage below the "always at least 1" guarantee
+-- combat.lua's own minimum otherwise enforces.
+function Resistances.apply(entity, amount, damageType)
+  if amount <= 0 then return amount end
+  local tier = Resistances.tierOf(entity, damageType or Resistances.PHYSICAL)
+  if tier == Resistances.IMMUNE then return 0 end
+  if tier == Resistances.RESIST then return math.floor(amount / 2) end
+  if tier == Resistances.WEAK then return math.floor(amount * 1.5) end
+  return amount
+end
+
+return Resistances

src/runewords.lua

@@ -0,0 +1,77 @@
+-- Rune stones drop as dungeon loot and slot into a weapon or armor's rune
+-- chain in the order they are socketed. A chain that exactly matches a
+-- cataloged sequence forms a runeword: a fixed, always-on stat bonus read
+-- live by combat.lua (the same additive-bonus pattern skills.lua already
+-- uses for berserk/mana shield), rather than baked permanently into the
+-- item's own power the way affixes.lua or crafting.lua's gems are - so a
+-- runeword needs no equip-time stat sync, and simply stops applying the
+-- instant a further rune breaks its exact match.
+
+local Items = require("items")
+
+local Runewords = {}
+
+Runewords.MAX_RUNES = 3
+
+Runewords.RUNES = { "sol", "ith", "tal", "ral", "eth", "amn" }
+
+-- Keyed by the chain's runes joined in slotted order - an exact match only,
+-- so a chain longer or shorter than a given word never qualifies for it.
+Runewords.WORDS = {
+  ["sol-ith"]     = { name = "Zenith",   attack = 3 },
+  ["tal-ral"]     = { name = "Bastion",  defense = 3 },
+  ["eth-amn-sol"] = { name = "Undertow", attack = 2, defense = 2 },
+}
+
+local function wordKey(runes)
+  return table.concat(runes, "-")
+end
+
+function Runewords.rune(key)
+  return { kind = Items.RUNE, rune = key, name = key .. " rune", glyph = "1" }
+end
+
+local function slottable(item)
+  return item.kind == Items.WEAPON or item.kind == Items.ARMOR
+end
+
+-- Appends `rune`'s key to `item`'s chain. Fails once the item is full or is
+-- not a weapon/armor; never fails on a rune that will not complete a known
+-- word, since an unmatched chain simply confers no bonus rather than being
+-- rejected outright - there is no wasted resource to protect against the way
+-- crafting.lua guards a gem merge against mismatched pairs.
+function Runewords.socket(item, rune)
+  if not slottable(item) then return false, "cannot hold runes" end
+  item.runes = item.runes or {}
+  if #item.runes >= Runewords.MAX_RUNES then return false, "the rune chain is full" end
+  item.runes[#item.runes + 1] = rune.rune
+  return true
+end
+
+-- The cataloged word `item`'s current chain forms, or nil if it matches none
+-- (including an empty chain, or one that no longer exactly matches any entry
+-- once it has grown past a shorter word's own length).
+function Runewords.activeWord(item)
+  if not item or not item.runes or #item.runes == 0 then return nil end
+  return Runewords.WORDS[wordKey(item.runes)]
+end
+
+function Runewords.attackBonus(entity)
+  local total = 0
+  local weaponWord = entity.weapon and Runewords.activeWord(entity.weapon)
+  if weaponWord then total = total + (weaponWord.attack or 0) end
+  local armorWord = entity.armor and Runewords.activeWord(entity.armor)
+  if armorWord then total = total + (armorWord.attack or 0) end
+  return total
+end
+
+function Runewords.defenseBonus(entity)
+  local total = 0
+  local weaponWord = entity.weapon and Runewords.activeWord(entity.weapon)
+  if weaponWord then total = total + (weaponWord.defense or 0) end
+  local armorWord = entity.armor and Runewords.activeWord(entity.armor)
+  if armorWord then total = total + (armorWord.defense or 0) end
+  return total
+end
+
+return Runewords

src/sanity.lua

@@ -0,0 +1,201 @@
+-- The player's grip on their own mind, tracked as a slow-moving meter
+-- alongside hp and mana rather than a temporary status.lua effect: nothing
+-- brews or casts sanity away in a single stroke, it only bleeds out from
+-- sustained exposure to dread (standing in the dark with a spent torch,
+-- corpses piling up nearby, undead in plain sight, a curse whose bite is
+-- already known, an infested floor's own creeping wrongness) and claws
+-- back just as slowly, one calm turn - or one potion of clarity - at a
+-- time. Falling tiers cost real attack and defense, exactly like
+-- encumbrance.lua's overloaded penalty, and the worst tier risks losing a
+-- turn outright to panic or giving the player's own position away with an
+-- involuntary scream, so the meter is never just flavour text on the
+-- status panel.
+
+local Factions = require("factions")
+local Curses = require("curses")
+local Atmosphere = require("atmosphere")
+local Stealth = require("stealth")
+
+local Sanity = {}
+
+Sanity.MAX = 100
+
+Sanity.COMPOSED = "composed"
+Sanity.SHAKEN = "shaken"
+Sanity.TERRIFIED = "terrified"
+Sanity.BROKEN = "broken"
+
+-- Tier ceilings: a value at or below TERRIFIED_MAX but above 0 reads as
+-- TERRIFIED, and so on upward. 0 itself is always BROKEN regardless of
+-- where these ceilings sit.
+Sanity.TERRIFIED_MAX = 30
+Sanity.SHAKEN_MAX = 60
+
+Sanity.DARKNESS_DREAD = 2
+Sanity.CORPSE_DREAD_PER = 1
+Sanity.CORPSE_DREAD_CAP = 4
+Sanity.UNDEAD_DREAD_PER = 2
+Sanity.UNDEAD_DREAD_CAP = 6
+Sanity.CURSE_DREAD = 2
+Sanity.WEATHER_DREAD = 2
+
+-- Passive drift back toward composure on any turn that accrued no dread
+-- at all - never enough on its own to outrun a floor still actively
+-- haunting the player, but reliable once they step clear of it.
+Sanity.CALM_RECOVERY = 1
+
+Sanity.PANIC_NUMERATOR = 1
+Sanity.PANIC_DENOMINATOR = 3
+
+Sanity.SCREAM_NUMERATOR = 1
+Sanity.SCREAM_DENOMINATOR = 4
+Sanity.SCREAM_RADIUS = 6
+
+local ATTACK_PENALTY = {
+  [Sanity.COMPOSED] = 0, [Sanity.SHAKEN] = -1, [Sanity.TERRIFIED] = -3, [Sanity.BROKEN] = -5,
+}
+local DEFENSE_PENALTY = {
+  [Sanity.COMPOSED] = 0, [Sanity.SHAKEN] = -1, [Sanity.TERRIFIED] = -2, [Sanity.BROKEN] = -4,
+}
+
+local function chebyshev(ax, ay, bx, by)
+  return math.max(math.abs(ax - bx), math.abs(ay - by))
+end
+
+-- A fresh entity - or a monster, which never accrues any dread of its own
+-- since nothing ever calls Sanity.tick for one - reads as fully composed.
+function Sanity.current(entity)
+  return entity.sanity or Sanity.MAX
+end
+
+function Sanity.tierOf(entity)
+  local value = Sanity.current(entity)
+  if value <= 0 then return Sanity.BROKEN end
+  if value <= Sanity.TERRIFIED_MAX then return Sanity.TERRIFIED end
+  if value <= Sanity.SHAKEN_MAX then return Sanity.SHAKEN end
+  return Sanity.COMPOSED
+end
+
+function Sanity.adjust(entity, delta)
+  local updated = Sanity.current(entity) + delta
+  if updated > Sanity.MAX then updated = Sanity.MAX end
+  if updated < 0 then updated = 0 end
+  entity.sanity = updated
+  return updated
+end
+
+function Sanity.attackPenalty(entity)
+  return ATTACK_PENALTY[Sanity.tierOf(entity)]
+end
+
+function Sanity.defensePenalty(entity)
+  return DEFENSE_PENALTY[Sanity.tierOf(entity)]
+end
+
+-- Each dread source below mirrors the vocabulary an existing module already
+-- uses (Atmosphere's weather keys, Factions' undead tag, Curses' reveal
+-- flag) rather than inventing a parallel one, and every source caps its own
+-- contribution so no single cause can spike the meter to zero in one turn.
+
+function Sanity.darknessDread(game)
+  if not game.level.dark then return 0 end
+  if game.player.light.fuel > 0 then return 0 end
+  return Sanity.DARKNESS_DREAD
+end
+
+function Sanity.corpseDread(game)
+  local count = 0
+  for _, corpse in ipairs(game.level.corpses) do
+    if chebyshev(corpse.x, corpse.y, game.player.x, game.player.y) <= 1 then
+      count = count + 1
+    end
+  end
+  return math.min(count * Sanity.CORPSE_DREAD_PER, Sanity.CORPSE_DREAD_CAP)
+end
+
+-- Only the undead currently visible weigh on the mind - one lurking
+-- somewhere unseen on the floor cannot, unlike a nearby corpse the player
+-- can smell without looking.
+function Sanity.undeadDread(game)
+  local count = 0
+  local map = game.level.map
+  for _, monster in ipairs(game.level.entities) do
+    if monster:isAlive() and monster.faction == Factions.UNDEAD
+      and game.visible[map:index(monster.x, monster.y)] then
+      count = count + 1
+    end
+  end
+  return math.min(count * Sanity.UNDEAD_DREAD_PER, Sanity.UNDEAD_DREAD_CAP)
+end
+
+-- A curse still hiding behind an ordinary appearance has not yet given its
+-- wearer anything to dread - only a revealed one gnaws at the mind.
+function Sanity.curseDread(entity)
+  for _, slot in ipairs(Curses.SLOTS) do
+    local item = entity[slot]
+    if Curses.isCursed(item) and Curses.isRevealed(item) then return Sanity.CURSE_DREAD end
+  end
+  return 0
+end
+
+function Sanity.weatherDread(weather)
+  if weather == Atmosphere.INFESTED then return Sanity.WEATHER_DREAD end
+  return 0
+end
+
+function Sanity.totalDread(game)
+  return Sanity.darknessDread(game)
+    + Sanity.corpseDread(game)
+    + Sanity.undeadDread(game)
+    + Sanity.curseDread(game.player)
+    + Sanity.weatherDread(game.level.weather)
+end
+
+-- Advances the player's sanity by one turn: every dread source at once, or
+-- - on a turn none of them fired at all - a small step back toward
+-- composure instead. Returns a log line the instant the player's tier
+-- actually changes, in either direction, or nil while it holds.
+function Sanity.tick(game)
+  local before = Sanity.tierOf(game.player)
+  local dread = Sanity.totalDread(game)
+  local worsening = dread > 0
+  if worsening then
+    Sanity.adjust(game.player, -dread)
+  else
+    Sanity.adjust(game.player, Sanity.CALM_RECOVERY)
+  end
+  local after = Sanity.tierOf(game.player)
+  if after == before then return nil end
+  if worsening then
+    if after == Sanity.BROKEN then return "your mind gives way to raw terror" end
+    if after == Sanity.TERRIFIED then return "dread claws at the edges of your sanity" end
+    return "your nerves begin to fray"
+  end
+  if after == Sanity.COMPOSED then return "your mind is your own again" end
+  return "your nerves start to steady"
+end
+
+-- BROKEN alone risks losing the turn outright to a fit of terror; every
+-- other tier always lets the player act. Rolls against `rng` so a seeded
+-- run always panics on the identical turns.
+function Sanity.rollPanic(rng, entity)
+  if Sanity.tierOf(entity) ~= Sanity.BROKEN then return false end
+  return rng:chance(Sanity.PANIC_NUMERATOR, Sanity.PANIC_DENOMINATOR)
+end
+
+-- TERRIFIED or worse risks an involuntary scream that alerts every living
+-- monster within earshot (reuses stealth.lua's own wake path) - the fear
+-- itself becomes a hazard to whoever else is on the floor.
+function Sanity.rollScream(rng, game)
+  local tier = Sanity.tierOf(game.player)
+  if tier ~= Sanity.TERRIFIED and tier ~= Sanity.BROKEN then return false end
+  if not rng:chance(Sanity.SCREAM_NUMERATOR, Sanity.SCREAM_DENOMINATOR) then return false end
+  for _, monster in ipairs(game.level.entities) do
+    if monster:isAlive() and chebyshev(monster.x, monster.y, game.player.x, game.player.y) <= Sanity.SCREAM_RADIUS then
+      Stealth.alert(monster, game.player.x, game.player.y)
+    end
+  end
+  return true
+end
+
+return Sanity

src/savegame.lua

@@ -0,0 +1,112 @@
+-- A reusable versioned, checksummed save container laid on top of
+-- serialize.lua's plain Lua-expression encoding. serialize.lua only knows how
+-- to turn a value into text and back; it has no notion of "this text might be
+-- truncated, hand-edited, or written by a codebase three versions ago". This
+-- module adds that layer: an envelope carrying a schema version and an
+-- FNV-1a32 checksum of its payload, plus a migration chain that walks old
+-- data forward one version at a time.
+--
+-- A file written before this module existed - a bare Serialize.saveFile dump
+-- with no envelope at all - is treated as implicit version 1, so an existing
+-- save on disk keeps loading instead of being rejected outright.
+--
+-- SaveGame.new(migrations) builds one codec for one call site. `migrations`
+-- is a 1-indexed array where migrations[v] transforms data from version v to
+-- v+1; the codec's CURRENT_VERSION is #migrations + 1. Two call sites with
+-- differently shaped data (a run's game state, a player's meta progression)
+-- each get their own codec with their own migration chain - this module
+-- knows nothing about either shape.
+
+local Serialize = require("serialize")
+
+local SaveGame = {}
+
+local MAGIC = "WARRENSAVE"
+local MASK32 = 0xFFFFFFFF
+
+-- FNV-1a, 32-bit. Verified below against the algorithm's published test
+-- vectors (fnv1a32("") and fnv1a32("a")), not just self-consistency.
+function SaveGame.fnv1a32(str)
+  local hash = 2166136261
+  for i = 1, #str do
+    hash = (hash ~ str:byte(i)) & MASK32
+    hash = (hash * 16777619) & MASK32
+  end
+  return hash
+end
+
+local function migrateForward(data, fromVersion, migrations, currentVersion)
+  for v = fromVersion, currentVersion - 1 do
+    data = migrations[v](data)
+  end
+  return data
+end
+
+-- Builds a codec bound to one migration chain. `migrations` may be empty
+-- (CURRENT_VERSION == 1); a version-1-only codec still gets checksumming and
+-- corruption detection for free.
+function SaveGame.new(migrations)
+  migrations = migrations or {}
+  local currentVersion = #migrations + 1
+  local codec = { CURRENT_VERSION = currentVersion }
+
+  function codec.encode(data)
+    local payload = Serialize.encode(data)
+    local envelope = {
+      magic = MAGIC,
+      version = currentVersion,
+      checksum = SaveGame.fnv1a32(payload),
+      payload = payload,
+    }
+    return Serialize.encode(envelope)
+  end
+
+  -- Returns (data) on success, or (nil, reason) on any failure. `reason` is
+  -- always one of: "missing" (only from .load, never from .decode), a string
+  -- starting with "corrupt:", or a string starting with "future version:".
+  function codec.decode(text)
+    local ok, value = pcall(Serialize.decode, text)
+    if not ok or type(value) ~= "table" then
+      return nil, "corrupt: cannot parse save data"
+    end
+    if value.magic ~= MAGIC then
+      -- No envelope at all: a save from before this codec existed. The
+      -- decoded value IS the raw data, at implicit version 1.
+      return migrateForward(value, 1, migrations, currentVersion)
+    end
+    if type(value.version) ~= "number" or type(value.payload) ~= "string"
+        or type(value.checksum) ~= "number" then
+      return nil, "corrupt: malformed save envelope"
+    end
+    if value.version > currentVersion then
+      return nil, "future version: save is v" .. value.version
+        .. ", this build reads up to v" .. currentVersion
+    end
+    if SaveGame.fnv1a32(value.payload) ~= value.checksum then
+      return nil, "corrupt: checksum mismatch"
+    end
+    local ok2, data = pcall(Serialize.decode, value.payload)
+    if not ok2 or type(data) ~= "table" then
+      return nil, "corrupt: cannot parse save payload"
+    end
+    return migrateForward(data, value.version, migrations, currentVersion)
+  end
+
+  function codec.save(path, data)
+    local file = assert(io.open(path, "w"))
+    file:write(codec.encode(data))
+    file:close()
+  end
+
+  function codec.load(path)
+    local file = io.open(path, "r")
+    if not file then return nil, "missing" end
+    local text = file:read("a")
+    file:close()
+    return codec.decode(text)
+  end
+
+  return codec
+end
+
+return SaveGame

src/scavenging.lua

@@ -0,0 +1,64 @@
+-- A third way to spend a fresh corpse, alongside Game:butcherCorpse's meal
+-- and Game:raiseCorpse's thrall: carving it for the herb its own kind
+-- carries rather than for food or an undead ally, so a cauldron (see
+-- alchemy.lua) can draw on combat itself and not only on whatever the floor
+-- happened to scatter. Every wild faction maps to a fixed herb, so the same
+-- species always yields the same ingredient no matter which floor or seed
+-- felled it - a goblinoid's crude poultice weed is always bloodroot, a
+-- drake's scorched hide is always emberleaf. A corpse already past its rot
+-- threshold (see Corpses.isRotten) has nothing left worth carving, and one
+-- left behind by anything without a bestiary entry - a bonded companion or
+-- a hired ally, never a wild monster - carries no herb at all; the corpse
+-- itself is spent either way it fails, exactly like Corpses.butcher's own
+-- certain trade, this is a deliberate trade the autopilot never makes on
+-- its own (see Game:scavengeCorpse), the same way it never raises one.
+
+local Corpses = require("corpses")
+local Alchemy = require("alchemy")
+local Monsters = require("monsters")
+local Factions = require("factions")
+
+local Scavenging = {}
+
+Scavenging.HERB_BY_FACTION = {
+  [Factions.VERMIN] = Alchemy.NIGHTCAP,
+  [Factions.GOBLINOID] = Alchemy.BLOODROOT,
+  [Factions.ORCISH] = Alchemy.BLOODROOT,
+  [Factions.BEAST] = Alchemy.EMBERLEAF,
+  [Factions.CULT] = Alchemy.NIGHTCAP,
+  [Factions.DRAKE] = Alchemy.EMBERLEAF,
+  [Factions.BANDIT] = Alchemy.SUNPETAL,
+  [Factions.MERCHANT] = Alchemy.SUNPETAL,
+}
+
+-- The herb key `corpse` would yield, or nil when its species is unknown to
+-- the bestiary (a companion's or hireling's own remains) or belongs to a
+-- faction (UNDEAD is the only one) with nothing mapped above - moot in
+-- practice since Corpses.leavesCorpse already refuses the undead a corpse
+-- at all, kept here only so an unmapped faction fails closed rather than
+-- erroring.
+function Scavenging.herbFor(corpse)
+  local spec = Monsters.byKey[corpse.species]
+  local faction = spec and spec.faction
+  return faction and Scavenging.HERB_BY_FACTION[faction]
+end
+
+-- Carves `corpse` for its herb instead of food, spending it in one stroke.
+-- Refuses without spending anything when the corpse has already rotted past
+-- use or its species yields no known herb; returns (false, reason) in
+-- either case so a caller never has to re-derive why.
+function Scavenging.harvest(game, corpse)
+  if Corpses.isRotten(corpse) then
+    return false, "the corpse has rotted too far to yield anything worth carving"
+  end
+  local herbKey = Scavenging.herbFor(corpse)
+  if not herbKey then
+    return false, "there is nothing worth carving from this corpse"
+  end
+  Corpses.remove(game.level, corpse)
+  local herb = Alchemy.herb(herbKey)
+  game.player.inventory[#game.player.inventory + 1] = herb
+  return true, string.format("you carve a %s from the %s corpse", herb.name, corpse.name)
+end
+
+return Scavenging

src/secrets.lua

@@ -0,0 +1,59 @@
+-- Secret doors: a wall tile that reads as ordinary rock (Tiles.WALL, same
+-- glyph, same isPassable/blocksSight as any other wall) until the player
+-- happens across it, gating a single hidden alcove otherwise unreachable
+-- from the rest of the floor (see builder.lua's dead-last placement).
+-- Detection is a passive roll against every still-hidden door within a
+-- step of the player, rolled once per player turn from Game:endPlayerTurn -
+-- the same shape disarm.lua's own trap sense already takes, and for the
+-- same reason: a once-per-round sweep rather than once per actor keeps a
+-- seeded run's discovery turn identical regardless of how many actors
+-- acted that round. Once found, the wall becomes a plain Tiles.DOOR_CLOSED -
+-- opened, from then on, through Game:openDoor exactly like any door the
+-- builder cut in the open, since nothing about a secret door's mechanics
+-- differs from an ordinary one once it is known to be there.
+
+local Tiles = require("tiles")
+
+local Secrets = {}
+
+Secrets.SEARCH_NUMERATOR = 1
+Secrets.SEARCH_DENOMINATOR = 5
+
+-- Sweeps every secret door within Chebyshev distance 1 of (px, py) that is
+-- not yet discovered, rolling each independently. Opens each newly-found
+-- door's map tile into a plain closed door on the spot and returns the
+-- doors discovered this call (in level.secretDoors order), so a caller only
+-- ever needs to report what was found.
+function Secrets.sweep(level, rng, px, py)
+  local found = {}
+  for _, door in ipairs(level.secretDoors) do
+    if not door.discovered
+      and math.max(math.abs(door.x - px), math.abs(door.y - py)) <= 1
+      and rng:chance(Secrets.SEARCH_NUMERATOR, Secrets.SEARCH_DENOMINATOR) then
+      door.discovered = true
+      level.map:set(door.x, door.y, Tiles.DOOR_CLOSED)
+      found[#found + 1] = door
+    end
+  end
+  return found
+end
+
+-- Discovers every still-hidden secret door on the floor outright, with no
+-- distance limit and no per-door roll - unlike Secrets.sweep's passive,
+-- one-step, one-in-five search above. Used only by captives.lua's
+-- interrogation, which trades a held captive for exactly this shortcut.
+-- Returns the doors this actually revealed (in level.secretDoors order), so
+-- a caller only ever needs to report what was found, same as Secrets.sweep.
+function Secrets.revealAll(level)
+  local found = {}
+  for _, door in ipairs(level.secretDoors) do
+    if not door.discovered then
+      door.discovered = true
+      level.map:set(door.x, door.y, Tiles.DOOR_CLOSED)
+      found[#found + 1] = door
+    end
+  end
+  return found
+end
+
+return Secrets

src/sets.lua

@@ -0,0 +1,159 @@
+-- Item sets: matching gear that all share a `set` tag and grants an
+-- escalating stat bonus once enough pieces are worn together at once - a
+-- fixed weapon/armor/ring/bow catalog of named pieces (see Sets.create),
+-- unlike affixes.lua's random roll bolted onto an ordinary base item. The
+-- bonus is read live off however many pieces of a given set the wearer
+-- currently has equipped (Sets.attackBonus/defenseBonus, wired into
+-- combat.lua exactly the way runewords.lua's own live bonus is), so
+-- swapping a single piece out mid-run instantly drops back to a lower
+-- threshold - or none at all - rather than needing an explicit uninstall
+-- step the way a socketed gem or an enchant would.
+
+local Items = require("items")
+
+local Sets = {}
+
+local SLOT_ORDER = { "weapon", "armor", "ring", "bow" }
+
+Sets.catalog = {
+  {
+    key = "ironclad", name = "Ironclad",
+    pieces = {
+      weapon = { name = "Ironclad Greatsword", power = 3 },
+      armor  = { name = "Ironclad Plate", power = 3 },
+      ring   = { name = "Ironclad Signet", attack = 0, defense = 1 },
+    },
+    -- Independent totals, not a stacking ladder: reaching the 3-piece
+    -- threshold replaces the 2-piece bonus rather than adding to it.
+    bonuses = {
+      [2] = { attack = 1, defense = 1 },
+      [3] = { attack = 2, defense = 3, regen = 1 },
+    },
+  },
+  {
+    key = "duskrunner", name = "Duskrunner",
+    pieces = {
+      weapon = { name = "Duskrunner Fang", power = 2 },
+      bow    = { name = "Duskrunner Bow", power = 2, range = 5 },
+      ring   = { name = "Duskrunner Loop", attack = 1, defense = 0 },
+    },
+    bonuses = {
+      [2] = { attack = 1 },
+      [3] = { attack = 3, defense = 1 },
+    },
+  },
+}
+
+Sets.byKey = {}
+for _, spec in ipairs(Sets.catalog) do
+  Sets.byKey[spec.key] = spec
+end
+
+-- Every (set, slot) pairing flattened in a fixed order, mirroring
+-- artifacts.lua's own Artifacts.order: the list a builder placement rolls
+-- a single uniform index into so every piece of every set is equally
+-- likely to turn up on a given floor.
+Sets.order = {}
+for _, spec in ipairs(Sets.catalog) do
+  for _, slot in ipairs(SLOT_ORDER) do
+    if spec.pieces[slot] then
+      Sets.order[#Sets.order + 1] = { set = spec.key, slot = slot }
+    end
+  end
+end
+
+-- Builds the dropped item for `setKey`'s `slot` piece in the same shape
+-- items.lua's own constructors return for that slot, tagged with the
+-- `set` field every function below keys its live bonus off.
+function Sets.create(setKey, slot)
+  local spec = Sets.byKey[setKey]
+  local piece = spec and spec.pieces[slot]
+  if not piece then return nil end
+  local item
+  if slot == "weapon" then item = Items.weapon(piece.name, piece.power)
+  elseif slot == "armor" then item = Items.armor(piece.name, piece.power)
+  elseif slot == "ring" then item = Items.ring(piece.name, piece.attack, piece.defense)
+  elseif slot == "bow" then item = Items.bow(piece.name, piece.power, piece.range)
+  end
+  item.set = setKey
+  return item
+end
+
+-- How many of `entity`'s four equip slots currently carry a piece of each
+-- set it has at least one piece of, keyed by set key. Walks a fixed slot
+-- order rather than pairs() over the entity itself, so the result never
+-- depends on Lua's unspecified table iteration order.
+function Sets.equippedCounts(entity)
+  local counts = {}
+  for _, slot in ipairs(SLOT_ORDER) do
+    local item = entity[slot]
+    if item and item.set then
+      counts[item.set] = (counts[item.set] or 0) + 1
+    end
+  end
+  return counts
+end
+
+-- The richest bonus tier `count` pieces of `setKey` qualify for, and the
+-- threshold it came from, or nil below its lowest threshold.
+function Sets.bonusFor(setKey, count)
+  local spec = Sets.byKey[setKey]
+  if not spec or not count or count <= 0 then return nil end
+  local best, bestThreshold
+  for threshold, bonus in pairs(spec.bonuses) do
+    if count >= threshold and (not bestThreshold or threshold > bestThreshold) then
+      best, bestThreshold = bonus, threshold
+    end
+  end
+  return best, bestThreshold
+end
+
+function Sets.attackBonus(entity)
+  local total = 0
+  local counts = Sets.equippedCounts(entity)
+  for _, spec in ipairs(Sets.catalog) do
+    local bonus = Sets.bonusFor(spec.key, counts[spec.key])
+    if bonus then total = total + (bonus.attack or 0) end
+  end
+  return total
+end
+
+function Sets.defenseBonus(entity)
+  local total = 0
+  local counts = Sets.equippedCounts(entity)
+  for _, spec in ipairs(Sets.catalog) do
+    local bonus = Sets.bonusFor(spec.key, counts[spec.key])
+    if bonus then total = total + (bonus.defense or 0) end
+  end
+  return total
+end
+
+-- Hp `entity` regenerates this turn from any active set bonus that grants
+-- one, summed the same way attack/defense are above.
+function Sets.regenAmount(entity)
+  local total = 0
+  local counts = Sets.equippedCounts(entity)
+  for _, spec in ipairs(Sets.catalog) do
+    local bonus = Sets.bonusFor(spec.key, counts[spec.key])
+    if bonus then total = total + (bonus.regen or 0) end
+  end
+  return total
+end
+
+-- A human-readable "Name Npc" tag for every set currently meeting its
+-- lowest threshold, in catalog order - read by render.lua's status panel
+-- and by nothing that affects game logic.
+function Sets.activeDescriptions(entity)
+  local counts = Sets.equippedCounts(entity)
+  local parts = {}
+  for _, spec in ipairs(Sets.catalog) do
+    local count = counts[spec.key]
+    if Sets.bonusFor(spec.key, count) then
+      parts[#parts + 1] = spec.name .. " " .. count .. "pc"
+    end
+  end
+  if #parts == 0 then return nil end
+  return table.concat(parts, ", ")
+end
+
+return Sets

src/shop.lua

@@ -0,0 +1,115 @@
+-- Gold economy: a price catalog for tradeable goods plus the buy/sell math for
+-- a shopkeeper's wares. Wares seeded on the floor by the builder carry a
+-- `price` and `shopId` tag on the ground entry (not the item), so a purchased
+-- item is indistinguishable from a found one once it reaches the inventory.
+
+local Items = require("items")
+local Affixes = require("affixes")
+local Factions = require("factions")
+local Mercenaries = require("mercenaries")
+
+local Shop = {}
+
+local POTION_PRICE = {
+  heal = 15, poison = 6, strength = 45, haste = 25, clarity = 20, cure = 30,
+  confuse = 8, blind = 8, levitate = 20,
+}
+local SCROLL_PRICE = { teleport = 25, identify = 18, mapping = 20, fireball = 35 }
+local FLAT_PRICE = { [Items.FOOD] = 5, [Items.TOME] = 55, [Items.PICK] = 40 }
+local AMMO_UNIT_PRICE = 2
+
+-- Catalog price for any tradeable item. Gear scales with its effective power
+-- or bonuses so a heavily-affixed drop costs more than a plain one.
+function Shop.priceOf(item)
+  if item.kind == Items.POTION then
+    return POTION_PRICE[item.effect] or 10
+  elseif item.kind == Items.SCROLL then
+    return SCROLL_PRICE[item.effect] or 10
+  elseif item.kind == Items.WEAPON or item.kind == Items.ARMOR then
+    return 20 + item.power * 15
+  elseif item.kind == Items.BOW then
+    return 25 + item.power * 12
+  elseif item.kind == Items.RING then
+    return 30 + (item.attack + item.defense) * 20
+  elseif item.kind == Items.AMMO then
+    return AMMO_UNIT_PRICE * (item.count or 1)
+  elseif item.kind == Items.CONTRACT then
+    return Mercenaries.byKey[item.hireling].hireCost
+  else
+    return FLAT_PRICE[item.kind] or 10
+  end
+end
+
+function Shop.sellValue(item)
+  return math.max(1, Shop.priceOf(item) // 2)
+end
+
+-- The price a shopkeeper actually charges once the player's standing with
+-- the merchant guild (see factions.lua) has had its say: sour relations mark
+-- goods up, warm ones discount them. `ground.price` (stamped once at
+-- generation - see builder.lua) stays the neutral catalog price throughout,
+-- so it keeps meaning "what a stranger pays" even as this moves the amount
+-- actually charged.
+function Shop.effectivePrice(game, ground)
+  return math.max(1, math.floor(ground.price * Factions.priceMultiplier(game.player, Factions.MERCHANT)))
+end
+
+-- Buys a warded ground item if the player can afford its reputation-adjusted
+-- price: deducts gold and transfers the item into the inventory. Returns the
+-- gold actually spent, or nil without side effects when the player is short.
+function Shop.buy(game, ground)
+  if not ground.price then return nil end
+  local price = Shop.effectivePrice(game, ground)
+  if game.player.gold < price then return nil end
+  game.player.gold = game.player.gold - price
+  game.player.inventory[#game.player.inventory + 1] = ground.item
+  return price
+end
+
+-- Sells an inventory item at half its catalog price (further scaled by
+-- merchant standing) and removes it.
+function Shop.sell(game, index)
+  local item = game.player.inventory[index]
+  if not item then return nil end
+  local value = math.max(1, math.floor(Shop.sellValue(item) / Factions.priceMultiplier(game.player, Factions.MERCHANT)))
+  game.player.gold = game.player.gold + value
+  table.remove(game.player.inventory, index)
+  return value
+end
+
+local weaponBases = { { name = "rapier", power = 3 }, { name = "war hammer", power = 5 } }
+local armorBases = { { name = "banded mail", power = 2 } }
+
+-- Rolls a small selection of wares for a shop room. Weapons and armour may
+-- still carry an affix, so the shop is a genuine alternative to a lucky drop
+-- rather than a strictly worse copy of one.
+function Shop.stock(rng)
+  local wares = {}
+  local slots = rng:range(3, 5)
+  for _ = 1, slots do
+    local roll = rng:range(1, 100)
+    local item
+    if roll <= 30 then
+      local effects = { "heal", "strength", "haste", "clarity", "cure" }
+      item = Items.potionOf(effects[rng:range(1, #effects)])
+    elseif roll <= 45 then
+      local effects = { "identify", "mapping", "fireball" }
+      item = Items.scroll(effects[rng:range(1, #effects)])
+    elseif roll <= 62 then
+      local base = weaponBases[rng:range(1, #weaponBases)]
+      item = Affixes.decorate(Items.weapon(base.name, base.power), Affixes.rollWeapon(rng))
+    elseif roll <= 75 then
+      local base = armorBases[rng:range(1, #armorBases)]
+      item = Affixes.decorate(Items.armor(base.name, base.power), Affixes.rollArmor(rng))
+    elseif roll <= 85 then
+      item = Items.ring("ring of the merchant", rng:range(0, 2), rng:range(0, 2))
+    else
+      local key = Mercenaries.order[rng:range(1, #Mercenaries.order)]
+      item = Items.contract(key, "contract: hire the " .. Mercenaries.byKey[key].name)
+    end
+    wares[#wares + 1] = item
+  end
+  return wares
+end
+
+return Shop

src/shrines.lua

@@ -0,0 +1,111 @@
+-- Wayside altars the player can pray at for a permanent boon at a gold price.
+-- A shrine's favor wears thin with use: each prayer at the same altar is more
+-- likely to backfire into a curse than the last, so greedily re-praying at a
+-- single shrine is a real risk rather than a free stat pump. Shrines are plain
+-- data on level.shrines, keyed by position, so they serialize like traps and
+-- hazards do with no special save-format handling.
+
+local Status = require("status")
+local Curses = require("curses")
+
+local Shrines = {}
+
+Shrines.WAR = "war"
+Shrines.VITALITY = "vitality"
+Shrines.WISDOM = "wisdom"
+Shrines.FORTUNE = "fortune"
+
+-- Fixed order so a given rng draw always names the same kind.
+Shrines.order = { Shrines.WAR, Shrines.VITALITY, Shrines.WISDOM, Shrines.FORTUNE }
+
+Shrines.names = {
+  [Shrines.WAR] = "shrine of war",
+  [Shrines.VITALITY] = "shrine of vitality",
+  [Shrines.WISDOM] = "shrine of wisdom",
+  [Shrines.FORTUNE] = "shrine of fortune",
+}
+
+local BASE_COST = 20
+local COST_STEP = 10
+
+-- Prayer cost climbs with prior use at this specific altar, the same shape as
+-- its rising curse risk: the shrine asks more and gives worse odds once its
+-- patience with the petitioner is spent.
+function Shrines.costFor(shrine)
+  return BASE_COST + shrine.uses * COST_STEP
+end
+
+-- Numerator over a denominator of 6: the first prayer risks 1-in-6, climbing
+-- by one for every prior use, capped at a certainty of 6-in-6.
+function Shrines.curseChance(shrine)
+  return math.min(shrine.uses + 1, 6), 6
+end
+
+local function grantBlessing(player, kind)
+  if kind == Shrines.WAR then
+    player.attack = player.attack + 1
+    player.baseAttack = player.baseAttack + 1
+    return "your grip tightens with martial favor"
+  elseif kind == Shrines.VITALITY then
+    player.maxHp = player.maxHp + 5
+    player.hp = player.hp + 5
+    return "vigor floods through you"
+  elseif kind == Shrines.WISDOM then
+    player.maxMana = player.maxMana + 3
+    player.mana = player.maxMana
+    return "arcane insight fills your mind"
+  else
+    local cleansed = false
+    local kept = {}
+    for _, active in ipairs(player.statuses) do
+      if active.kind == Status.POISON or active.kind == Status.BURNING
+        or active.kind == Status.WEAKEN or active.kind == Status.SLOW then
+        cleansed = true
+      else
+        kept[#kept + 1] = active
+      end
+    end
+    player.statuses = kept
+    Status.apply(player, Status.SHIELD, 10, 1)
+    if Curses.cleanseWorn(player) > 0 then cleansed = true end
+    if cleansed then
+      return "fortune cleanses your ailments and wards you"
+    end
+    return "fortune wards you against harm"
+  end
+end
+
+local function inflictCurse(player)
+  Status.apply(player, Status.WEAKEN, 8, 1)
+  Status.apply(player, Status.SLOW, 8, 1)
+  return "the shrine's favor turns against you"
+end
+
+-- Attempts a prayer at `shrine` for `game.player`. When the price cannot be
+-- met nothing is spent and this returns (false, lines). Otherwise the gold is
+-- always spent, the shrine's use count always advances (so its price and
+-- curse odds keep climbing), and this returns (true, lines) describing
+-- whichever of a blessing or a curse landed.
+function Shrines.pray(game, shrine)
+  local player = game.player
+  local cost = Shrines.costFor(shrine)
+  if player.gold < cost then
+    return false, { "you cannot afford " .. Shrines.names[shrine.kind] .. "'s price" }
+  end
+  player.gold = player.gold - cost
+  local numerator, denominator = Shrines.curseChance(shrine)
+  local cursed = game.rng:chance(numerator, denominator)
+  shrine.uses = shrine.uses + 1
+  local line
+  if cursed then
+    line = inflictCurse(player)
+  else
+    line = grantBlessing(player, shrine.kind)
+  end
+  return true, {
+    string.format("you pray at the %s for %d gold", Shrines.names[shrine.kind], cost),
+    line,
+  }
+end
+
+return Shrines

src/skills.lua

@@ -0,0 +1,281 @@
+-- Class skill trees. Each class (classes.lua) unlocks three skills, one
+-- learned per skill point (granted on level-up, see progression.lua): an
+-- active that spends the player's turn like a spell, and passives that fold
+-- straight into combat/spells/ranged. Passive checks all guard on
+-- `entity.skills` being present, so calling any of these on a monster (which
+-- never has the field) is always a safe no-op - the same shape status.lua
+-- uses for its own modifiers.
+
+local Los = require("los")
+local Items = require("items")
+local Resistances = require("resistances")
+
+local Skills = {}
+
+Skills.active = {
+  cleave      = { name = "cleave",       class = "fighter", reqLevel = 1, cooldown = 3 },
+  secondWind  = { name = "second wind",  class = "fighter", reqLevel = 3, cooldown = 12 },
+  poisonBlade = { name = "poison blade", class = "rogue",   reqLevel = 5, cooldown = 6 },
+  meditate    = { name = "meditate",     class = "mage",    reqLevel = 3, cooldown = 0 },
+  multishot   = { name = "multishot",    class = "ranger",  reqLevel = 1, cooldown = 5 },
+}
+
+Skills.passive = {
+  berserk    = { name = "berserk",    class = "fighter", reqLevel = 5 },
+  backstab   = { name = "backstab",   class = "rogue",   reqLevel = 1 },
+  evasion    = { name = "evasion",    class = "rogue",   reqLevel = 3 },
+  overload   = { name = "overload",   class = "mage",    reqLevel = 1 },
+  manaShield = { name = "mana shield", class = "mage",   reqLevel = 5 },
+  camouflage = { name = "camouflage", class = "ranger",  reqLevel = 3 },
+  trueshot   = { name = "trueshot",   class = "ranger",  reqLevel = 5 },
+}
+
+local function defOf(key)
+  return Skills.active[key] or Skills.passive[key]
+end
+
+-- Every skill key belonging to `classKey`, active and passive alike, in a
+-- fixed alphabetical order so autopilot and tests see a stable pick sequence
+-- regardless of Lua's unordered `pairs` iteration over the catalogs above.
+function Skills.forClass(classKey)
+  local list = {}
+  for key, def in pairs(Skills.active) do
+    if def.class == classKey then list[#list + 1] = key end
+  end
+  for key, def in pairs(Skills.passive) do
+    if def.class == classKey then list[#list + 1] = key end
+  end
+  table.sort(list)
+  return list
+end
+
+function Skills.has(entity, key)
+  return entity.skills ~= nil and entity.skills[key] == true
+end
+
+-- Spends one of the player's skill points to permanently learn `key`.
+-- Returns (true, message) on success or (false, message) with no state
+-- changed - no point spent - on failure.
+function Skills.learn(player, key)
+  local def = defOf(key)
+  if not def then return false, "there is no such skill" end
+  if player.class ~= def.class then return false, "that skill is not part of your training" end
+  if player.level < def.reqLevel then return false, "you are not experienced enough for that yet" end
+  if Skills.has(player, key) then return false, "you already know that" end
+  if (player.skillPoints or 0) <= 0 then return false, "you have no skill points to spend" end
+  player.skillPoints = player.skillPoints - 1
+  player.skills[key] = true
+  return true, "you learn " .. def.name
+end
+
+function Skills.tickCooldowns(player)
+  for key, turns in pairs(player.skillCooldowns) do
+    if turns > 0 then player.skillCooldowns[key] = turns - 1 end
+  end
+end
+
+-- Passive hooks. Each is a small, pure function of entity/game state so
+-- combat.lua, spells.lua, ranged.lua and game.lua can call straight into it
+-- without either side needing to know about the other's active-skill logic.
+
+-- Rogue: a target still at full hp has not yet reacted to the fight, so the
+-- first strike lands twice as hard.
+function Skills.meleeDamageMultiplier(attacker, defender)
+  if Skills.has(attacker, "backstab") and defender.hp == defender.maxHp then
+    return 2
+  end
+  return 1
+end
+
+-- Rogue: a trained dodge fully negates an incoming melee hit one time in
+-- four. Checks `has` before touching the rng so an unlearned/unlearnable
+-- defender never perturbs the rng stream.
+function Skills.evades(game, defender)
+  if not Skills.has(defender, "evasion") then return false end
+  return game.rng:chance(1, 4)
+end
+
+-- Fighter: a flat attack surge once hp drops to a third or less of max.
+function Skills.attackBonus(entity)
+  if entity.skills and entity.skills.berserk and entity.hp <= entity.maxHp * 0.34 then
+    return 4
+  end
+  return 0
+end
+
+-- Mage: an actively maintained ward that lapses once the pool it draws on
+-- runs low.
+function Skills.defenseBonus(entity)
+  if entity.skills and entity.skills.manaShield and (entity.mana or 0) >= 5 then
+    return 3
+  end
+  return 0
+end
+
+-- Mage: damaging spells hit a quarter harder.
+function Skills.spellDamageMultiplier(caster)
+  if Skills.has(caster, "overload") then return 1.25 end
+  return 1
+end
+
+-- Ranger: a steadier draw adds flat damage to every loosed arrow.
+function Skills.rangedDamageBonus(entity)
+  if Skills.has(entity, "trueshot") then return 3 end
+  return 0
+end
+
+-- Ranger: blends into the dark. Only ever shrinks a monster's detection
+-- range on a lightless floor - camouflage on a lit one would just be standing
+-- in the open.
+function Skills.detectionPenalty(player, dark)
+  if dark and Skills.has(player, "camouflage") then return 3 end
+  return 0
+end
+
+-- Active skills. Each takes the live `game` object (duck-typed, mirroring
+-- spells.lua's Spells.cast) so it can log, award kills and touch level state
+-- without skills.lua ever requiring the game module back.
+
+local EIGHT_DIRS = {
+  { 1, 0 }, { -1, 0 }, { 0, 1 }, { 0, -1 },
+  { 1, 1 }, { 1, -1 }, { -1, 1 }, { -1, -1 },
+}
+
+local function statAttack(entity)
+  return entity.effectiveAttack and entity:effectiveAttack() or entity.attack
+end
+
+local function statDefense(entity)
+  return entity.effectiveDefense and entity:effectiveDefense() or entity.defense
+end
+
+-- Fighter: strikes the primary target in full through the normal attack path
+-- (so backstab/riders/kill-xp all still apply) and every other monster
+-- standing next to the player for half that raw swing.
+function Skills.useCleave(game, target)
+  if not target or not target:isAlive() then return false, { "there is nothing there to cleave" } end
+  local player = game.player
+  local dist = math.max(math.abs(target.x - player.x), math.abs(target.y - player.y))
+  if dist > 1 then return false, { "cleave only reaches an adjacent foe" } end
+  player.skillCooldowns.cleave = Skills.active.cleave.cooldown
+  local lines = {}
+  game:playerAttack(target)
+  local damageType = (player.weapon and player.weapon.damageType) or Resistances.PHYSICAL
+  for _, dir in ipairs(EIGHT_DIRS) do
+    local other = game.level:entityAt(player.x + dir[1], player.y + dir[2])
+    if other and other ~= target and other:isAlive() then
+      local dealt = math.floor((statAttack(player) - statDefense(other)) * 0.5)
+      if dealt < 1 then dealt = 1 end
+      dealt = Resistances.apply(other, dealt, damageType)
+      other.hp = other.hp - dealt
+      lines[#lines + 1] = string.format("your cleave catches %s for %d", other.name, dealt)
+      if not other:isAlive() then game:awardKill(other) end
+    end
+  end
+  return true, lines
+end
+
+-- Fighter: an instant breather, restoring three tenths of max hp.
+function Skills.useSecondWind(game)
+  local player = game.player
+  player.skillCooldowns.secondWind = Skills.active.secondWind.cooldown
+  local amount = math.floor(player.maxHp * 0.3)
+  local before = player.hp
+  player.hp = math.min(player.maxHp, player.hp + amount)
+  return true, { string.format("you catch your breath and recover %d", player.hp - before) }
+end
+
+-- Rogue: readies venom on the next melee swing rather than dealing damage
+-- itself. Cooldown starts immediately so it cannot be re-readied before the
+-- swing that consumes it even lands.
+function Skills.usePoisonBlade(game)
+  local player = game.player
+  player.skillCooldowns.poisonBlade = Skills.active.poisonBlade.cooldown
+  player.pendingPoisonBlade = true
+  return true, { "your blade drips with venom" }
+end
+
+-- Consumes a readied poison blade, if any. Called from Game:playerAttack
+-- after every melee hit so the very next swing - and only that one - carries
+-- the venom.
+function Skills.consumePoisonBlade(player)
+  if player.pendingPoisonBlade then
+    player.pendingPoisonBlade = nil
+    return true
+  end
+  return false
+end
+
+-- Mage: trades the turn for a flat mana refill, cheaper than waiting out the
+-- passive one-per-turn regen from hungerTorchTick.
+function Skills.useMeditate(game)
+  local player = game.player
+  local before = player.mana
+  player.mana = math.min(player.maxMana, player.mana + 6)
+  return true, { string.format("you meditate and recover %d mana", player.mana - before) }
+end
+
+local function firstAmmoIndex(entity)
+  for i, item in ipairs(entity.inventory) do
+    if item.kind == Items.AMMO and item.count > 0 then return i end
+  end
+  return nil
+end
+
+local function canReach(game, x1, y1, x2, y2, range)
+  local dist = math.max(math.abs(x1 - x2), math.abs(y1 - y2))
+  return dist <= range and Los.clear(game.level.map, x1, y1, x2, y2)
+end
+
+-- Ranger: a single arrow splits to strike up to two targets - the first for
+-- a full shot, the second for half - and only ever costs one arrow.
+function Skills.useMultishot(game, t1, t2)
+  local shooter = game.player
+  local bow = shooter.bow
+  if not bow then return false, { "you have no bow readied" } end
+  local ammoIdx = firstAmmoIndex(shooter)
+  if not ammoIdx then return false, { "you have no arrows left" } end
+  local targets = {}
+  for _, t in ipairs({ t1, t2 }) do
+    if t and t:isAlive() and canReach(game, shooter.x, shooter.y, t.x, t.y, bow.range) then
+      targets[#targets + 1] = t
+    end
+  end
+  if #targets == 0 then return false, { "no target in range" } end
+  shooter.skillCooldowns.multishot = Skills.active.multishot.cooldown
+  local ammo = shooter.inventory[ammoIdx]
+  ammo.count = ammo.count - 1
+  if ammo.count <= 0 then table.remove(shooter.inventory, ammoIdx) end
+  local lines = {}
+  for i, t in ipairs(targets) do
+    local share = (i == 1) and 1 or 0.5
+    local dealt = math.floor((shooter.baseAttack + bow.power - t:effectiveDefense()) * share)
+    if dealt < 1 then dealt = 1 end
+    dealt = Resistances.apply(t, dealt, Resistances.PHYSICAL)
+    t.hp = t.hp - dealt
+    lines[#lines + 1] = string.format("your arrow splits and strikes %s for %d", t.name, dealt)
+    if not t:isAlive() then game:awardKill(t) end
+  end
+  return true, lines
+end
+
+-- Attempts to use the active skill `key` on behalf of the player. Returns
+-- (true, lines) on success or (false, lines) with an explanatory line and no
+-- state changed on failure - unknown skill, still on cooldown, or the
+-- specific skill's own preconditions.
+function Skills.use(game, key, ...)
+  local def = Skills.active[key]
+  if not def then return false, { "you have no such skill to use" } end
+  local player = game.player
+  if not Skills.has(player, key) then return false, { "you haven't learned that skill" } end
+  if (player.skillCooldowns[key] or 0) > 0 then return false, { "that skill is not ready yet" } end
+  if key == "cleave" then return Skills.useCleave(game, ...)
+  elseif key == "secondWind" then return Skills.useSecondWind(game)
+  elseif key == "poisonBlade" then return Skills.usePoisonBlade(game)
+  elseif key == "meditate" then return Skills.useMeditate(game)
+  elseif key == "multishot" then return Skills.useMultishot(game, ...)
+  end
+  return false, { "that skill does nothing yet" }
+end
+
+return Skills

src/spells.lua

@@ -0,0 +1,249 @@
+-- Mana-fuelled spellbook. Spells are learned permanently from tomes (see
+-- Items.TOME) and cast by spending mana from a pool that regenerates each
+-- player turn. Targeted spells additionally need line of sight and range,
+-- checked here before any mana is spent so a bad cast is free. Damage and
+-- teleport spells reach into the game the same way potion/scroll effects do.
+
+local Los = require("los")
+local Status = require("status")
+local Skills = require("skills")
+local Resistances = require("resistances")
+local Conductivity = require("conductivity")
+local Polymorph = require("polymorph")
+local Disease = require("disease")
+
+local Spells = {}
+
+local DIRS4 = { { 1, 0 }, { -1, 0 }, { 0, 1 }, { 0, -1 } }
+
+-- Every walkable, unoccupied cell within `radius` orthogonal steps of the
+-- caster, excluding the caster's own cell. Used by blink so a short-range
+-- teleport only ever lands somewhere the caster could in principle walk to.
+local function reachableWithin(game, caster, radius)
+  local map = game.level.map
+  local start = map:index(caster.x, caster.y)
+  local dist = { [start] = 0 }
+  local queue = { { caster.x, caster.y, start } }
+  local head = 1
+  local cells = {}
+  while head <= #queue do
+    local cur = queue[head]
+    head = head + 1
+    local cx, cy, idx = cur[1], cur[2], cur[3]
+    local d = dist[idx]
+    if idx ~= start then cells[#cells + 1] = { x = cx, y = cy } end
+    if d < radius then
+      for _, dir in ipairs(DIRS4) do
+        local nx, ny = cx + dir[1], cy + dir[2]
+        if map:inBounds(nx, ny) and map:isWalkable(nx, ny) then
+          local nIdx = map:index(nx, ny)
+          if not dist[nIdx] then
+            dist[nIdx] = d + 1
+            queue[#queue + 1] = { nx, ny, nIdx }
+          end
+        end
+      end
+    end
+  end
+  return cells
+end
+
+Spells.catalog = {
+  missile = {
+    name = "magic missile", cost = 3, targeted = true, range = 6,
+    cast = function(game, caster, target)
+      local raw = math.floor((6 + (caster.level or 1)) * Skills.spellDamageMultiplier(caster))
+      local dmg = Resistances.apply(target, raw, Resistances.ARCANE)
+      target.hp = target.hp - dmg
+      if dmg <= 0 then
+        game.log:add(string.format("a bolt of force washes over %s harmlessly", target.name))
+      else
+        game.log:add(string.format("a bolt of force hits %s for %d", target.name, dmg))
+      end
+      if not target:isAlive() then game:awardKill(target) end
+      return {}
+    end,
+  },
+  heal = {
+    name = "minor heal", cost = 5, targeted = false,
+    cast = function(_, caster)
+      local amount = 10 + (caster.level or 1) * 2
+      local before = caster.hp
+      caster.hp = math.min(caster.maxHp, caster.hp + amount)
+      return { string.format("you mend for %d", caster.hp - before) }
+    end,
+  },
+  -- Mirrors effects.lua's "cure" potion handler (both lift disease and every
+  -- Status.HOSTILE debuff) but reachable without needing the item on hand -
+  -- until now the only way to shed poison/burning/stun/slow/weaken/discord/
+  -- confuse/blind was to survive until they expired on their own.
+  cleanse = {
+    name = "cleansing ward", cost = 5, targeted = false,
+    cast = function(_, caster)
+      local diseaseCured = Disease.cure(caster)
+      local lifted = Status.cureHostile(caster)
+      if diseaseCured and #lifted > 0 then
+        return { string.format("your affliction lifts, and the %s fades", table.concat(lifted, ", ")) }
+      elseif diseaseCured then
+        return { "your affliction lifts" }
+      elseif #lifted > 0 then
+        return { string.format("the %s fades", table.concat(lifted, ", ")) }
+      end
+      return { "you feel a faint tingle, but had nothing to cleanse" }
+    end,
+  },
+  shield = {
+    name = "arcane shield", cost = 4, targeted = false,
+    cast = function(_, caster)
+      Status.apply(caster, Status.SHIELD, 15, 1)
+      return { "a shimmering ward surrounds you" }
+    end,
+  },
+  shock = {
+    name = "shock bolt", cost = 4, targeted = true, range = 5,
+    cast = function(game, caster, target)
+      local raw = math.floor((5 + (caster.level or 1)) * Skills.spellDamageMultiplier(caster))
+      local dmg = Conductivity.applyLightning(target, raw)
+      target.hp = target.hp - dmg
+      if dmg <= 0 then
+        game.log:add(string.format("a crackle of lightning washes over %s harmlessly", target.name))
+      elseif Conductivity.isWet(target) then
+        game.log:add(string.format("lightning arcs through the water clinging to %s for %d", target.name, dmg))
+      else
+        game.log:add(string.format("a bolt of lightning strikes %s for %d", target.name, dmg))
+      end
+      if not target:isAlive() then game:awardKill(target) end
+      return {}
+    end,
+  },
+  -- Fractures the target's mind for a few turns: while it lasts, the
+  -- target attacks whatever creature stands nearest it - ally or foe,
+  -- including the caster's own companion/hireling/thrall if one strays
+  -- close enough - instead of chasing the caster (see infighting.lua). No
+  -- direct damage of its own; the value is entirely in redirecting a
+  -- threat, or turning a cluster of monsters against itself.
+  discord = {
+    name = "discord", cost = 5, targeted = true, range = 6,
+    cast = function(_, _, target)
+      Status.apply(target, Status.DISCORD, 8, 1)
+      return { string.format("%s's mind fractures with discord", target.name) }
+    end,
+  },
+  -- Scrambles the target's own sense of direction for a few turns (see
+  -- status.lua's Status.CONFUSE, and its mirror in Game:movePlayer/Ai.act) -
+  -- a lucky roll can send a dangerous chaser stumbling into a wall, a lava
+  -- pool, or one of its own allies instead of at the caster.
+  confuse = {
+    name = "confusing hex", cost = 4, targeted = true, range = 5,
+    cast = function(_, _, target)
+      Status.apply(target, Status.CONFUSE, 6, 1)
+      return { string.format("%s's senses reel with confusion", target.name) }
+    end,
+  },
+  -- Snuffs the target's sight down to melee range for a few turns (see
+  -- status.lua's Status.BLIND, folded into Game:effectiveRadius/canSeePlayer)
+  -- - unlike confuse, which garbles the target's own movement, a blinded
+  -- monster keeps walking straight at its last known heading and simply
+  -- stops noticing anything past arm's reach, useful against archers and
+  -- casters whose whole threat depends on seeing the caster from a distance.
+  blind = {
+    name = "veil of shadow", cost = 4, targeted = true, range = 5,
+    cast = function(_, _, target)
+      Status.apply(target, Status.BLIND, 6, 1)
+      return { string.format("a veil of shadow falls over %s's eyes", target.name) }
+    end,
+  },
+  -- Saps the target's fighting strength for a few turns (see status.lua's
+  -- Status.WEAKEN). Until now WEAKEN only ever flowed toward the player - a
+  -- shaman's ranged curse, a cursed shrine's backfired prayer - with no way
+  -- for the player to return the favor against a monster; this spell is
+  -- that missing direction, shaped exactly like confuse/blind above (no
+  -- direct damage, just a debuff riding on Status.apply).
+  weaken = {
+    name = "withering hex", cost = 4, targeted = true, range = 5,
+    cast = function(_, _, target)
+      Status.apply(target, Status.WEAKEN, 6, 1)
+      return { string.format("%s's strength withers", target.name) }
+    end,
+  },
+  -- Rewrites the target's body outright rather than damaging or debuffing
+  -- it (see polymorph.lua). A pricier cast than any other targeted spell
+  -- here, since a lucky roll can turn a real threat into something the
+  -- caster can safely ignore - and an unlucky one can just as easily make
+  -- it worse, the same double-edged risk a shrine's backfired prayer carries.
+  polymorph = {
+    name = "polymorph", cost = 9, targeted = true, range = 5,
+    cast = function(game, _, target)
+      local oldName = target.name
+      local pool = Polymorph.pool(game.depth)
+      local spec = Polymorph.transform(target, game.rng, pool)
+      if not spec then
+        return { string.format("the magic washes over %s, changing nothing", oldName) }
+      end
+      return { string.format("%s convulses and reforms into a %s", oldName, spec.name) }
+    end,
+  },
+  -- A self-buff shaped exactly like shield, but see status.lua's
+  -- Status.LEVITATE for the payoff: for as long as it lasts, the caster
+  -- drifts clear of lava, a chasm's drop, an ice tile's slide, and any
+  -- ground-pressure trap (Game:checkTerrainFor/checkTrapFor) instead of
+  -- soaking a hit.
+  levitate = {
+    name = "levitation", cost = 5, targeted = false,
+    cast = function(_, caster)
+      Status.apply(caster, Status.LEVITATE, 20, 1)
+      return { "you rise off the ground" }
+    end,
+  },
+  blink = {
+    name = "blink", cost = 6, targeted = false,
+    cast = function(game, caster)
+      local free = {}
+      for _, cell in ipairs(reachableWithin(game, caster, 5)) do
+        if not game.level:entityAt(cell.x, cell.y) then
+          free[#free + 1] = cell
+        end
+      end
+      if #free == 0 then return { "there is nowhere to blink" } end
+      local pick = free[game.rng:range(1, #free)]
+      caster.x, caster.y = pick.x, pick.y
+      return { "you blink through space" }
+    end,
+  },
+}
+
+function Spells.knows(caster, key)
+  for _, known in ipairs(caster.spellsKnown) do
+    if known == key then return true end
+  end
+  return false
+end
+
+function Spells.learn(caster, key)
+  if not Spells.catalog[key] then return false end
+  if Spells.knows(caster, key) then return false end
+  caster.spellsKnown[#caster.spellsKnown + 1] = key
+  return true
+end
+
+-- Attempts to cast `key` on behalf of `caster`. Returns (true, lines) on a
+-- successful cast, or (false, lines) with an explanatory line and no state
+-- changed - no mana spent, no cooldown, nothing - on failure.
+function Spells.cast(game, caster, key, target)
+  local spell = Spells.catalog[key]
+  if not spell then return false, { "you don't know that spell" } end
+  if not Spells.knows(caster, key) then return false, { "you haven't learned that spell" } end
+  if caster.mana < spell.cost then return false, { "not enough mana" } end
+  if spell.targeted then
+    if not target or not target:isAlive() then return false, { "no target" } end
+    local dist = math.max(math.abs(target.x - caster.x), math.abs(target.y - caster.y))
+    if dist > spell.range then return false, { "out of range" } end
+    if not Los.clear(game.level.map, caster.x, caster.y, target.x, target.y) then
+      return false, { "no clear shot" }
+    end
+  end
+  caster.mana = caster.mana - spell.cost
+  return true, spell.cast(game, caster, target) or {}
+end
+
+return Spells

src/status.lua

@@ -2,6 +2,12 @@
 -- damage-over-time drains hp, regeneration restores it, stun skips the action,
 -- and haste/slow/strength feed modifiers into speed and combat. Effects are
 -- plain data on entity.statuses so they serialize without special handling.
+-- Poison and burning route their tick damage through resistances.lua, so a
+-- poison-immune undead shrugs off venom entirely and a fire-resistant hide
+-- only smoulders at half the usual potency.
+
+local Resistances = require("resistances")
+local Conductivity = require("conductivity")
 
 local Status = {}
 
@@ -12,20 +18,54 @@ Status.REGEN = "regen"
 Status.HASTE = "haste"
 Status.SLOW = "slow"
 Status.STRENGTH = "strength"
+Status.SHIELD = "shield"
+Status.WEAKEN = "weaken"
+Status.DISCORD = "discord"
+Status.CONFUSE = "confuse"
+Status.BLIND = "blind"
+Status.LEVITATE = "levitate"
+
+-- Odds, rolled fresh each turn a confused actor tries to act, that its own
+-- chosen direction gets overridden by a random one instead - see
+-- Game:movePlayer's stumble branch and Ai.act's mirror of it for monsters.
+Status.CONFUSE_NUMERATOR = 1
+Status.CONFUSE_DENOMINATOR = 2
+
+-- Debuffs a cleansing effect (see effects.lua's "cure" handler) is allowed to
+-- strip early. Buffs (REGEN/HASTE/STRENGTH/SHIELD/LEVITATE) are deliberately
+-- excluded - a curative should not also strip a buff the entity chose to be
+-- carrying.
+Status.HOSTILE = {
+  [Status.POISON] = true,
+  [Status.BURNING] = true,
+  [Status.STUN] = true,
+  [Status.SLOW] = true,
+  [Status.WEAKEN] = true,
+  [Status.DISCORD] = true,
+  [Status.CONFUSE] = true,
+  [Status.BLIND] = true,
+}
 
 Status.defs = {
   [Status.POISON] = {
     glyph = "p",
     tick = function(entity, potency)
-      entity.hp = entity.hp - potency
-      return string.format("poison saps %s for %d", entity.name, potency)
+      local dealt = Resistances.apply(entity, potency, Resistances.POISON)
+      entity.hp = entity.hp - dealt
+      if dealt <= 0 then
+        return entity.kind == "player" and "you shrug off the poison"
+          or string.format("%s shrugs off the poison", entity.name)
+      end
+      return string.format("poison saps %s for %d", entity.name, dealt)
     end,
   },
   [Status.BURNING] = {
     glyph = "b",
     tick = function(entity, potency)
-      entity.hp = entity.hp - potency
-      return string.format("flames sear %s for %d", entity.name, potency)
+      local dealt = Conductivity.applyFire(entity, potency)
+      entity.hp = entity.hp - dealt
+      if dealt <= 0 then return string.format("the flames wash over %s harmlessly", entity.name) end
+      return string.format("flames sear %s for %d", entity.name, dealt)
     end,
   },
   [Status.REGEN] = {
@@ -34,7 +74,9 @@ Status.defs = {
       local before = entity.hp
       entity.hp = math.min(entity.maxHp, entity.hp + potency)
       if entity.hp > before then
-        return string.format("%s knits flesh for %d", entity.name, entity.hp - before)
+        local healed = entity.hp - before
+        return entity.kind == "player" and string.format("you knit flesh for %d", healed)
+          or string.format("%s knits flesh for %d", entity.name, healed)
       end
       return nil
     end,
@@ -43,9 +85,38 @@ Status.defs = {
   [Status.HASTE] = { glyph = "h", speed = 60 },
   [Status.SLOW] = { glyph = "l", speed = -50 },
   [Status.STRENGTH] = { glyph = "S", attack = 3 },
+  [Status.SHIELD] = { glyph = "d", defense = 4 },
+  [Status.WEAKEN] = { glyph = "c", attack = -3 },
+  -- No tick or stat modifier of its own: infighting.lua reads Status.has
+  -- directly to decide whether a monster's turn goes to Ai.act at all.
+  [Status.DISCORD] = { glyph = "o" },
+  -- No tick or stat modifier of its own either: Game:movePlayer and Ai.act
+  -- both read Status.has directly, at the point they would otherwise commit
+  -- to a chosen direction, to roll whether that direction gets overridden.
+  [Status.CONFUSE] = { glyph = "f" },
+  -- No tick or stat modifier of its own: Game:effectiveRadius and
+  -- Game:canSeePlayer both read Status.has directly, clamping vision instead
+  -- of touching hp or combat stats - confuse scrambles where you go, blind
+  -- scrambles what you can tell is there in the first place.
+  [Status.BLIND] = { glyph = "!" },
+  -- No tick or stat modifier of its own: Game:checkTerrainFor and
+  -- Game:checkTrapFor (plus movePlayer's own trap check) read Status.has
+  -- directly, letting a levitating entity drift clear of lava, a chasm's
+  -- drop, an ice tile's slide, and any ground-pressure trap without ever
+  -- touching whatever would otherwise trigger them.
+  [Status.LEVITATE] = { glyph = "y" },
 }
 
+-- Records `kind` as active on `entity` for `duration` more ticks at `potency`,
+-- or refreshes an already-active instance of the same kind to whichever of
+-- the two durations and potencies is stronger. A soaked entity's own
+-- dampness (see conductivity.lua) refuses a BURNING application outright,
+-- before anything is recorded - returns nil and leaves entity.statuses
+-- untouched, exactly as if the call had never been made.
 function Status.apply(entity, kind, duration, potency)
+  if kind == Status.BURNING and Conductivity.resistsIgnition(entity) then
+    return nil
+  end
   potency = potency or 1
   for _, active in ipairs(entity.statuses) do
     if active.kind == kind then
@@ -66,6 +137,36 @@ function Status.has(entity, kind)
   return false
 end
 
+-- Strips one named status outright, independent of its remaining duration.
+-- Returns whether anything was actually removed.
+function Status.remove(entity, kind)
+  for i, active in ipairs(entity.statuses) do
+    if active.kind == kind then
+      table.remove(entity.statuses, i)
+      return true
+    end
+  end
+  return false
+end
+
+-- Strips every active status listed in Status.HOSTILE (poison, burning,
+-- stun, slow, weaken, discord, confuse, blind), leaving buffs untouched.
+-- Returns the kinds actually removed, in the order they were active, for
+-- callers that want to report exactly what a cleansing effect lifted.
+function Status.cureHostile(entity)
+  local removed = {}
+  local kept = {}
+  for _, active in ipairs(entity.statuses) do
+    if Status.HOSTILE[active.kind] then
+      removed[#removed + 1] = active.kind
+    else
+      kept[#kept + 1] = active
+    end
+  end
+  entity.statuses = kept
+  return removed
+end
+
 -- Advances every effect one step, applying its tick and dropping expired ones.
 -- Returns the log lines produced this step, in effect order.
 function Status.tick(entity)
@@ -104,6 +205,15 @@ function Status.attackModifier(entity)
   return delta
 end
 
+function Status.defenseModifier(entity)
+  local delta = 0
+  for _, active in ipairs(entity.statuses) do
+    local def = Status.defs[active.kind]
+    if def.defense then delta = delta + def.defense end
+  end
+  return delta
+end
+
 function Status.skipsTurn(entity)
   for _, active in ipairs(entity.statuses) do
     if Status.defs[active.kind].skipsTurn then return true end

src/stealth.lua

@@ -0,0 +1,154 @@
+-- Monster alertness state machine layered on top of ai.lua's chase/pack/etc
+-- behaviours. A wild monster the builder places starts dormant (asleep) and
+-- takes no action at all until something wakes it: on each of its own turns
+-- a still-dormant monster rolls a wake chance driven by distance, line of
+-- sight and the player's detection-penalty skills (see skills.lua's
+-- camouflage), guaranteed once the player stands right next to it. Landing
+-- any hit on it - melee, spell or ranged - wakes it outright regardless of
+-- the roll.
+--
+-- Once alert a monster hunts exactly as ai.lua always has; losing line of
+-- sight for several turns in a row drops it to searching, where it makes
+-- for wherever it last saw the player instead of running its usual
+-- behaviour. Giving up the search with nothing found puts it back to sleep.
+--
+-- A blow struck against a monster that is still dormant is a sneak attack:
+-- it never saw the swing coming, so it lands for several times the normal
+-- damage (see Stealth.sneakMultiplier, read by Game:playerAttack).
+--
+-- Bosses, the shopkeeper and anything summoned or split mid-fight (see
+-- game.lua's spawnMinion and bosses.lua's create) start "hunting" outright
+-- rather than dormant, so none of this changes behaviour that was already
+-- always-alert. A monster built directly without ever passing through
+-- builder.lua's placement loop - as most of tests/run.lua's fixtures do -
+-- also defaults to "hunting" whenever its awareness field is simply absent,
+-- which keeps every existing hand-built scenario acting exactly as it did
+-- before this module existed.
+
+local Los = require("los")
+local Skills = require("skills")
+
+local Stealth = {}
+
+Stealth.DORMANT = "dormant"
+Stealth.HUNTING = "hunting"
+Stealth.SEARCHING = "searching"
+
+Stealth.WAKE_RADIUS = 6
+Stealth.TRACK_RADIUS = 20
+Stealth.LOST_TURNS_LIMIT = 4
+Stealth.SEARCH_TURNS_LIMIT = 4
+Stealth.SNEAK_MULTIPLIER = 3
+
+function Stealth.isUnaware(monster)
+  return monster.awareness == Stealth.DORMANT
+end
+
+-- Read by Game:playerAttack before Stealth.alert (below) fires on the same
+-- swing, so the bonus is computed against the state the monster was
+-- actually in the instant the blow landed.
+function Stealth.sneakMultiplier(monster)
+  if Stealth.isUnaware(monster) then return Stealth.SNEAK_MULTIPLIER end
+  return 1
+end
+
+-- Called the instant a monster is provoked by any offensive player action -
+-- whatever it was doing before, it now knows exactly where the player is.
+function Stealth.alert(monster, px, py)
+  monster.awareness = Stealth.HUNTING
+  monster.lastKnownX, monster.lastKnownY = px, py
+  monster.lostTurns = 0
+end
+
+-- Called when noise.lua's flood reaches a still-dormant monster (see
+-- game.lua's Game:emitNoise). Unlike alert() above - a direct provocation,
+-- which snaps a monster straight to hunting with the player's exact
+-- position - a monster that only heard something does not know it was the
+-- player specifically, or where they actually are now: it starts searching
+-- the noise's own origin instead, exactly like a hunter that just lost
+-- track (see Stealth.tick's searching branch below), so it may well arrive
+-- to find nothing there and give up. A monster that is not currently
+-- dormant is already tracking something better than a noise and ignores
+-- this outright.
+function Stealth.hear(monster, x, y)
+  if monster.awareness ~= Stealth.DORMANT then return end
+  monster.awareness = Stealth.SEARCHING
+  monster.lastKnownX, monster.lastKnownY = x, y
+  monster.searchTurns = 0
+end
+
+local function chebyshev(ax, ay, bx, by)
+  return math.max(math.abs(ax - bx), math.abs(ay - by))
+end
+
+local function canSpot(game, monster, radius)
+  local penalty = Skills.detectionPenalty(game.player, game.level.dark)
+  local effective = radius - penalty
+  if effective < 1 then effective = 1 end
+  if chebyshev(monster.x, monster.y, game.player.x, game.player.y) > effective then return false end
+  return Los.clear(game.level.map, monster.x, monster.y, game.player.x, game.player.y)
+end
+
+-- Whether a dormant monster notices the player this turn: guaranteed once
+-- adjacent, otherwise a chance that improves the closer the player stands,
+-- scaled against the monster's own (penalty-adjusted) waking radius.
+local function rollWake(game, monster)
+  if not canSpot(game, monster, Stealth.WAKE_RADIUS) then return false end
+  local dist = chebyshev(monster.x, monster.y, game.player.x, game.player.y)
+  if dist <= 1 then return true end
+  local penalty = Skills.detectionPenalty(game.player, game.level.dark)
+  local radius = math.max(Stealth.WAKE_RADIUS - penalty, 1)
+  local roll = game.rng:range(1, radius)
+  return roll <= (radius - dist + 1)
+end
+
+-- Advances one monster's alertness ahead of its upcoming turn and reports
+-- whether game.lua should still run its normal ability/ai dispatch this
+-- turn. A monster that stays dormant, or one that spends the turn marching
+-- back toward wherever it last saw the player, returns false - stealth.lua
+-- has already fully resolved its turn (for dormant, that means doing
+-- nothing at all).
+function Stealth.tick(game, monster)
+  local awareness = monster.awareness or Stealth.HUNTING
+  if awareness == Stealth.DORMANT then
+    if rollWake(game, monster) then
+      Stealth.alert(monster, game.player.x, game.player.y)
+      game.log:add(string.format("%s stirs awake", monster.name))
+      return true
+    end
+    return false
+  end
+  if awareness == Stealth.SEARCHING then
+    if canSpot(game, monster, Stealth.TRACK_RADIUS) then
+      Stealth.alert(monster, game.player.x, game.player.y)
+      return true
+    end
+    monster.searchTurns = (monster.searchTurns or 0) + 1
+    if monster.lastKnownX and (monster.x ~= monster.lastKnownX or monster.y ~= monster.lastKnownY) then
+      game:stepMonsterToward(monster, monster.lastKnownX, monster.lastKnownY)
+    end
+    if monster.searchTurns >= Stealth.SEARCH_TURNS_LIMIT then
+      monster.awareness = Stealth.DORMANT
+      monster.lastKnownX, monster.lastKnownY = nil, nil
+      monster.lostTurns, monster.searchTurns = nil, nil
+      game.log:add(string.format("%s gives up the search and settles back down", monster.name))
+    end
+    return false
+  end
+  -- hunting
+  if canSpot(game, monster, Stealth.TRACK_RADIUS) then
+    monster.lastKnownX, monster.lastKnownY = game.player.x, game.player.y
+    monster.lostTurns = 0
+    return true
+  end
+  monster.lostTurns = (monster.lostTurns or 0) + 1
+  if monster.lostTurns >= Stealth.LOST_TURNS_LIMIT and monster.lastKnownX then
+    monster.awareness = Stealth.SEARCHING
+    monster.searchTurns = 0
+    game.log:add(string.format("%s loses track of you", monster.name))
+    return Stealth.tick(game, monster)
+  end
+  return true
+end
+
+return Stealth

src/streaks.lua

@@ -0,0 +1,57 @@
+-- Win/loss streak tracking over meta.lua's own run history: not "how many
+-- wins in total" (Meta.recordRun's own totalRuns/wins tally already answers
+-- that) but how many of the *most recent* runs in a row ended the same
+-- way - the number that actually swings the instant a lucky or unlucky run
+-- lands, unlike a lifetime win rate that a hundred prior runs already numbs.
+
+local Streaks = {}
+
+Streaks.HISTORY_CAP = 50
+
+function Streaks.new()
+  return {}
+end
+
+-- Appends `won` (a boolean) as the newest entry, trimming the oldest once
+-- history grows past Streaks.HISTORY_CAP - a streak only ever needs to look
+-- back so far, and an unbounded history would grow meta.lua's save file
+-- forever for no further benefit.
+function Streaks.record(history, won)
+  history[#history + 1] = won
+  while #history > Streaks.HISTORY_CAP do
+    table.remove(history, 1)
+  end
+end
+
+-- Length of the run of identical outcomes ending at the most recent entry,
+-- and which outcome that is - (0, nil) for an empty history. A single win
+-- right after a loss reads as a streak of exactly 1, not 0: the run just
+-- recorded is itself part of its own streak.
+function Streaks.current(history)
+  if #history == 0 then return 0, nil end
+  local outcome = history[#history]
+  local length = 0
+  for i = #history, 1, -1 do
+    if history[i] ~= outcome then break end
+    length = length + 1
+  end
+  return length, outcome
+end
+
+-- The longest run of consecutive wins anywhere in history, not just the one
+-- still active - a player's all-time best winning streak survives even
+-- after it eventually breaks.
+function Streaks.bestWinStreak(history)
+  local best, running = 0, 0
+  for _, won in ipairs(history) do
+    if won then
+      running = running + 1
+      if running > best then best = running end
+    else
+      running = 0
+    end
+  end
+  return best
+end
+
+return Streaks

src/terrain.lua

@@ -0,0 +1,49 @@
+-- Permanent map terrain that punishes careless movement, as opposed to
+-- hazards.lua's fire and gas which are timed and spawned mid-game. Lava
+-- scorches whoever stands on it every time they step there, a chasm drops
+-- the player to the floor below (or swallows a monster outright), and ice
+-- keeps sliding a traveller in the direction they started moving until
+-- something stops them. None of it spreads, fades, or needs saving beyond
+-- the glyph already baked into the map by the builder.
+
+local Tiles = require("tiles")
+local Status = require("status")
+local Resistances = require("resistances")
+
+local Terrain = {}
+
+Terrain.LAVA_DAMAGE = 8
+
+-- Slides entity through consecutive ice tiles in direction (dx, dy), from
+-- wherever it just came to rest. Stops the instant the current tile isn't
+-- ice, the next cell is unwalkable, or another actor already occupies it -
+-- so ice never carries a traveller through a wall or on top of someone else.
+function Terrain.slide(level, entity, dx, dy)
+  local map = level.map
+  while map:get(entity.x, entity.y) == Tiles.ICE do
+    local nx, ny = entity.x + dx, entity.y + dy
+    if not map:isWalkable(nx, ny) then break end
+    if level:entityAt(nx, ny) then break end
+    entity.x, entity.y = nx, ny
+  end
+end
+
+-- Applies lava's burn to whoever is currently standing on it. Returns a log
+-- line, or nil when the tile underfoot isn't lava.
+function Terrain.afflictLava(level, entity)
+  if level.map:get(entity.x, entity.y) ~= Tiles.LAVA then return nil end
+  local dealt = Resistances.apply(entity, Terrain.LAVA_DAMAGE, Resistances.FIRE)
+  entity.hp = entity.hp - dealt
+  if dealt <= 0 then
+    return entity.kind == "player" and "you wade through the lava unharmed"
+      or string.format("%s wades through the lava unharmed", entity.name)
+  end
+  Status.apply(entity, Status.BURNING, 2, math.max(1, dealt // 3))
+  return string.format("molten rock sears %s for %d", entity.name, dealt)
+end
+
+function Terrain.isChasm(level, entity)
+  return level.map:get(entity.x, entity.y) == Tiles.CHASM
+end
+
+return Terrain

src/throwing.lua

@@ -0,0 +1,85 @@
+-- Player ranged option that costs no mana: any spare weapon or potion sitting
+-- in the inventory (not the one currently wielded) can be hurled at a monster
+-- in range and line of sight. A thrown weapon hits harder than a melee swing
+-- and lands where it struck, ready to be picked back up; a thrown potion
+-- shatters and visits its effect on the target instead of the thrower, which
+-- only makes sense for potions with a hostile reading.
+
+local Los = require("los")
+local Status = require("status")
+local Items = require("items")
+local Hazards = require("hazards")
+local Resistances = require("resistances")
+
+local Throwing = {}
+
+Throwing.RANGE = 6
+local POWER_MULT = 2
+
+-- Hostile reading of each potion effect. Potions with no meaningful effect on
+-- an enemy (healing, strength) just shatter harmlessly rather than helping
+-- whoever they were thrown at.
+local hostileEffects = {
+  poison = function(game, target)
+    Status.apply(target, Status.POISON, 6, 3)
+    Hazards.spawnGas(game.level, target.x, target.y, 4, 2)
+    return string.format("the potion shatters, poisoning %s in a cloud of fumes", target.name)
+  end,
+  haste = function(_, target)
+    Status.apply(target, Status.HASTE, 10, 1)
+    return string.format("the potion shatters, and %s bolts away", target.name)
+  end,
+  confuse = function(_, target)
+    Status.apply(target, Status.CONFUSE, 6, 1)
+    return string.format("the potion shatters, and %s reels in confusion", target.name)
+  end,
+  blind = function(_, target)
+    Status.apply(target, Status.BLIND, 6, 1)
+    return string.format("the potion shatters in a blinding flash, and %s is struck blind", target.name)
+  end,
+  -- Same hostile reading as haste above: lifting a dangerous target off the
+  -- ground lets it drift clear of whatever lava, chasm, or trap the thrower
+  -- was counting on to block or punish it (see status.lua's Status.LEVITATE),
+  -- so handing it to an enemy is a liability, not a gift.
+  levitate = function(_, target)
+    Status.apply(target, Status.LEVITATE, 10, 1)
+    return string.format("the potion shatters, and %s rises off the ground", target.name)
+  end,
+}
+
+function Throwing.canThrow(item)
+  return item.kind == Items.WEAPON or item.kind == Items.POTION
+end
+
+function Throwing.canReach(game, x1, y1, x2, y2)
+  local dist = math.max(math.abs(x1 - x2), math.abs(y1 - y2))
+  return dist <= Throwing.RANGE and Los.clear(game.level.map, x1, y1, x2, y2)
+end
+
+-- Resolves a thrown item against a target. Returns (true, lines) if the item
+-- left the thrower's hand - whether or not it did anything useful on arrival
+-- - or (false, lines) if the throw never happened at all.
+function Throwing.resolve(game, thrower, item, target)
+  if not Throwing.canThrow(item) then
+    return false, { "that can't be thrown" }
+  end
+  if not target or not target:isAlive() then
+    return false, { "no target" }
+  end
+  if not Throwing.canReach(game, thrower.x, thrower.y, target.x, target.y) then
+    return false, { "you have no clear throw" }
+  end
+  if item.kind == Items.WEAPON then
+    local dmg = Resistances.apply(target, item.power * POWER_MULT, item.damageType or Resistances.PHYSICAL)
+    target.hp = target.hp - dmg
+    local lines = { string.format("your thrown %s hits %s for %d", item.name, target.name, dmg) }
+    game.level.floorItems[#game.level.floorItems + 1] = { x = target.x, y = target.y, item = item }
+    if not target:isAlive() then game:awardKill(target) end
+    return true, lines
+  end
+  local handler = hostileEffects[item.effect]
+  local line = handler and handler(game, target) or "the potion shatters harmlessly"
+  return true, { line }
+end
+
+return Throwing

src/tiles.lua

@@ -14,6 +14,14 @@ Tiles.DOOR_LOCKED = "x"
 Tiles.TRAP = "^"
 Tiles.WATER = "~"
 Tiles.RUBBLE = ":"
+Tiles.LAVA = "%"
+Tiles.CHASM = "V"
+Tiles.ICE = "-"
+Tiles.LEVER = "H"
+Tiles.LEVER_PULLED = "I"
+Tiles.VAULT_DOOR = "K"
+Tiles.GATE_CLOSED = "8"
+Tiles.GATE_OPEN = "9"
 
 local props = {
   [Tiles.WALL]        = { walkable = false, blocksSight = true,  door = false },
@@ -26,6 +34,14 @@ local props = {
   [Tiles.TRAP]        = { walkable = true,  blocksSight = false, door = false },
   [Tiles.WATER]       = { walkable = true,  blocksSight = false, door = false },
   [Tiles.RUBBLE]      = { walkable = true,  blocksSight = false, door = false },
+  [Tiles.LAVA]        = { walkable = true,  blocksSight = false, door = false, lava = true },
+  [Tiles.CHASM]       = { walkable = true,  blocksSight = false, door = false, chasm = true },
+  [Tiles.ICE]         = { walkable = true,  blocksSight = false, door = false, ice = true },
+  [Tiles.LEVER]        = { walkable = true,  blocksSight = false, door = false },
+  [Tiles.LEVER_PULLED] = { walkable = true,  blocksSight = false, door = false },
+  [Tiles.VAULT_DOOR]   = { walkable = false, blocksSight = true,  door = false, vault = true },
+  [Tiles.GATE_CLOSED]  = { walkable = false, blocksSight = true,  door = false, gate = true },
+  [Tiles.GATE_OPEN]    = { walkable = true,  blocksSight = false, door = false, gate = true },
 }
 
 local wallProps = props[Tiles.WALL]
@@ -50,4 +66,24 @@ function Tiles.isClosedDoor(glyph)
   return glyph == Tiles.DOOR_CLOSED or glyph == Tiles.DOOR_LOCKED
 end
 
+function Tiles.isLava(glyph)
+  return Tiles.of(glyph).lava == true
+end
+
+function Tiles.isChasm(glyph)
+  return Tiles.of(glyph).chasm == true
+end
+
+function Tiles.isIce(glyph)
+  return Tiles.of(glyph).ice == true
+end
+
+function Tiles.isVaultDoor(glyph)
+  return Tiles.of(glyph).vault == true
+end
+
+function Tiles.isGate(glyph)
+  return Tiles.of(glyph).gate == true
+end
+
 return Tiles

src/titles.lua

@@ -0,0 +1,37 @@
+-- Renown-gated titles: a flavor rank meta.lua's own banked renown climbs
+-- through, one tier per crossed threshold, entirely separate from a
+-- character's class - a title describes how far this save file's whole
+-- history has come, not what any single run's build looked like.
+
+local Titles = {}
+
+Titles.LADDER = {
+  { threshold = 0, name = "Whelp" },
+  { threshold = 50, name = "Delver" },
+  { threshold = 150, name = "Warden" },
+  { threshold = 350, name = "Vanquisher" },
+  { threshold = 700, name = "Warren Lord" },
+  { threshold = 1500, name = "Undying" },
+}
+
+-- The highest title whose threshold `renown` clears, walked from the top of
+-- the ladder down so a renown total that clears several thresholds at once
+-- always resolves to the hardest-earned name rather than the first match.
+function Titles.forRenown(renown)
+  for i = #Titles.LADDER, 1, -1 do
+    if renown >= Titles.LADDER[i].threshold then return Titles.LADDER[i].name end
+  end
+  return Titles.LADDER[1].name
+end
+
+-- Renown still needed to clear the next threshold above `renown`, or nil
+-- once renown has already cleared the top of the ladder and there is
+-- nothing left to climb toward.
+function Titles.toNext(renown)
+  for _, tier in ipairs(Titles.LADDER) do
+    if renown < tier.threshold then return tier.threshold - renown end
+  end
+  return nil
+end
+
+return Titles

src/vaults.lua

@@ -0,0 +1,64 @@
+-- Lever-gated treasure rooms. A vault door only swings open once every lever
+-- sharing its id has been pulled; the builder places the door at a doorway
+-- pinch point and scatters its levers only on the side already reachable
+-- without crossing it, so the puzzle is always solvable and the reward
+-- sealed behind the door is always genuinely gated by it (see builder.lua's
+-- vault placement, drawn dead last so it never perturbs any earlier
+-- system's rng sequence).
+
+local Items = require("items")
+local Affixes = require("affixes")
+
+local Vaults = {}
+
+local treasureWeapons = {
+  { name = "vault greatsword", power = 7 },
+  { name = "vault warhammer",  power = 8 },
+}
+local treasureArmors = {
+  { name = "vault aegis", power = 6 },
+}
+
+-- A guaranteed affix on a base already well above anything the floor's own
+-- loot table can roll at this depth - the deterministic reward for solving
+-- the puzzle, distinct from a normal drop's coin-flip affix (see
+-- affixes.rollWeapon/rollArmor).
+function Vaults.treasure(rng, depth)
+  if rng:chance(1, 2) then
+    local base = treasureWeapons[rng:range(1, #treasureWeapons)]
+    local item = Items.weapon(base.name, base.power + depth // 3)
+    return Affixes.decorate(item, Affixes.weapon[rng:range(1, #Affixes.weapon)])
+  end
+  local base = treasureArmors[rng:range(1, #treasureArmors)]
+  local item = Items.armor(base.name, base.power + depth // 3)
+  return Affixes.decorate(item, Affixes.armor[rng:range(1, #Affixes.armor)])
+end
+
+function Vaults.doorFor(level, id)
+  for _, door in ipairs(level.vaultDoors) do
+    if door.id == id then return door end
+  end
+  return nil
+end
+
+local function allPulled(level, id)
+  for _, lever in ipairs(level.vaultLevers) do
+    if lever.id == id and not lever.pulled then return false end
+  end
+  return true
+end
+
+-- Pulls `lever`, an idempotent no-op returning false if it was already
+-- thrown. Returns (true, door) the instant this pull completes every lever
+-- sharing its id and the door has not opened yet, or (true, nil) for a pull
+-- that leaves the vault still sealed (or already open).
+function Vaults.pull(level, lever)
+  if lever.pulled then return false end
+  lever.pulled = true
+  if not allPulled(level, lever.id) then return true, nil end
+  local door = Vaults.doorFor(level, lever.id)
+  if door and not door.opened then return true, door end
+  return true, nil
+end
+
+return Vaults

warren.lua

@@ -1,12 +1,44 @@
 -- Headless entry point. Examples:
 --   lua warren.lua --seed 42 --auto 50
 --   lua warren.lua --seed 7 --auto 30 --save run.sav
+--   lua warren.lua --seed 3 --class ranger --auto 50
 --   lua warren.lua --load run.sav
+--   lua warren.lua --meta legacy.sav --seed 3 --auto 200
+--   lua warren.lua --meta legacy.sav --buy vigor
+--   lua warren.lua --meta legacy.sav --report
+--   lua warren.lua --meta legacy.sav --seed 3 --auto 200 --mutators famine,nightblind
+--   lua warren.lua --seed 3 --auto 200 --morgue run.morgue
+--   lua warren.lua --seed 3 --auto 200 --verify
+--   lua warren.lua --challenge 42 --auto 200
+--   lua warren.lua --meta legacy.sav --export-csv runs.csv
+--   lua warren.lua --meta legacy.sav --export-compendium bestiary.csv
+--   lua warren.lua --seed 3 --class fighter --play
+--   lua warren.lua --load run.sav --play
 
 local scriptDir = arg[0]:match("^(.*)[/\\]") or "."
 package.path = scriptDir .. "/src/?.lua;" .. scriptDir .. "/../src/?.lua;" .. package.path
 
 local Game = require("game")
+local Meta = require("meta")
+local Compendium = require("compendium")
+local Graves = require("graves")
+local Ascension = require("ascension")
+local Morgue = require("morgue")
+local Leaderboard = require("leaderboard")
+local Replay = require("replay")
+local Challenges = require("challenges")
+local Analytics = require("analytics")
+local Titles = require("titles")
+local Export = require("export")
+local Streaks = require("streaks")
+
+local function splitCommaList(text)
+  local list = {}
+  for part in text:gmatch("[^,]+") do
+    list[#list + 1] = part
+  end
+  return list
+end
 
 local function parseArgs(argv)
   local opts = { seed = os.time() & 0xFFFF, auto = 0 }
@@ -17,22 +49,215 @@ local function parseArgs(argv)
     elseif flag == "--auto" then opts.auto = math.tointeger(tonumber(argv[i + 1])); i = i + 2
     elseif flag == "--save" then opts.save = argv[i + 1]; i = i + 2
     elseif flag == "--load" then opts.load = argv[i + 1]; i = i + 2
+    elseif flag == "--class" then opts.class = argv[i + 1]; i = i + 2
+    elseif flag == "--meta" then opts.metaPath = argv[i + 1]; i = i + 2
+    elseif flag == "--buy" then opts.buy = argv[i + 1]; i = i + 2
+    elseif flag == "--report" then opts.report = true; i = i + 1
+    elseif flag == "--morgue" then opts.morguePath = argv[i + 1]; i = i + 2
+    elseif flag == "--verify" then opts.verify = true; i = i + 1
+    elseif flag == "--mutators" then opts.mutators = splitCommaList(argv[i + 1]); i = i + 2
+    elseif flag == "--challenge" then opts.challengeDay = math.tointeger(tonumber(argv[i + 1])); i = i + 2
+    elseif flag == "--export-csv" then opts.exportPath = argv[i + 1]; i = i + 2
+    elseif flag == "--export-compendium" then opts.exportCompendiumPath = argv[i + 1]; i = i + 2
+    elseif flag == "--play" then opts.play = true; i = i + 1
     else i = i + 1 end
   end
   return opts
 end
 
+-- Interactive terminal loop: renders the current frame, reads one line of
+-- input, and hands it straight to Game:manualStep - the same command
+-- interpreter (see commands.lua) a scripted test drives without a real
+-- terminal attached. "quit"/"exit"/"q" leave the run exactly where it
+-- stands rather than ending it, so a save taken right after --play still
+-- captures whatever the last accepted command left behind. Runs until the
+-- player dies, wins, quits, or stdin closes (a redirected script of
+-- commands hitting EOF ends the loop the same way an interactive quit
+-- would).
+local function playLoop(game)
+  io.write(game:render(), "\n")
+  while game.player:isAlive() and not game.won do
+    io.write("> ")
+    io.flush()
+    local line = io.read("l")
+    if not line then break end
+    local command = line:match("^%s*(.-)%s*$")
+    if command == "quit" or command == "exit" or command == "q" then
+      break
+    elseif command ~= "" then
+      local _, message = game:manualStep(command)
+      if message then io.write(message, "\n") end
+      io.write(game:render(), "\n")
+    end
+  end
+  if game.won then
+    io.write("you escape with the Amulet of Warren - you win!\n")
+  elseif not game.player:isAlive() then
+    io.write("you have died.\n")
+  end
+end
+
+local function reportMeta(meta)
+  local toNext = Titles.toNext(meta.renown)
+  local titleLine = toNext and string.format("%s (%d renown to next title)", Titles.forRenown(meta.renown), toNext)
+    or string.format("%s (top of the ladder)", Titles.forRenown(meta.renown))
+  io.write(string.format("renown %d | runs %d | wins %d | best depth %d | win rate %.0f%% | title %s\n",
+    meta.renown, meta.totalRuns, meta.wins, meta.bestDepth, Analytics.winRate(meta) * 100, titleLine))
+  local streakLength, streakOutcome = Streaks.current(meta.runHistory)
+  io.write(string.format("streak: %d %s in a row | best win streak %d\n",
+    streakLength, streakOutcome == nil and "runs" or (streakOutcome and "wins" or "losses"),
+    Streaks.bestWinStreak(meta.runHistory)))
+  for _, def in ipairs(Meta.PERKS) do
+    io.write(string.format("  perk %-12s %s (%d renown)\n",
+      def.key, Meta.isOwned(meta, def.key) and "[owned]" or "[locked]", def.cost))
+  end
+  io.write("challenges:\n")
+  for _, preset in ipairs(Challenges.CATALOG) do
+    io.write("  " .. Challenges.describe(preset) .. "\n")
+  end
+  for _, ach in ipairs(Meta.ACHIEVEMENTS) do
+    io.write(string.format("  achievement %-14s %s\n",
+      ach.key, meta.achievements[ach.key] and "[unlocked]" or "[locked]"))
+  end
+  for _, def in ipairs(Ascension.MUTATORS) do
+    io.write(string.format("  mutator %-12s %s (+%d%% renown) %s\n",
+      def.key, def.desc, def.renownBonus, Ascension.isUnlocked(meta, def.key) and "[unlocked]" or "[locked]"))
+  end
+  io.write("compendium:\n")
+  for _, entry in ipairs(Compendium.entries(meta.compendium or Compendium.new())) do
+    if entry.seen then
+      io.write(string.format("  %-14s slain %-3d %s\n", entry.name, entry.kills, entry.flavor or ""))
+    else
+      io.write(string.format("  %-14s [undiscovered]\n", entry.key))
+    end
+  end
+  local board = meta.leaderboard or Leaderboard.new()
+  io.write("leaderboard:\n")
+  for rank, entry in ipairs(Leaderboard.top(board)) do
+    io.write(string.format("  #%-2d %-6d %-10s depth %-2d turn %-5d seed %s %s\n",
+      rank, entry.score, entry.className, entry.depth, entry.turn, tostring(entry.seed),
+      entry.won and "(won)" or ""))
+  end
+  if #board > 0 then
+    io.write(string.format("  average score %.1f | favorite class %s\n",
+      Analytics.averageScore(board), Analytics.favoriteClass(board) or "none"))
+  end
+end
+
 local opts = parseArgs(arg)
-local game = opts.load and Game.load(opts.load) or Game.new(opts.seed)
+
+local challengePreset
+if opts.challengeDay then
+  challengePreset, opts.seed = Challenges.forDay(opts.challengeDay)
+  opts.class = challengePreset.class
+  opts.mutators = challengePreset.mutators
+  io.write(string.format("challenge: %s, seed %d\n", Challenges.describe(challengePreset), opts.seed))
+end
+
+local meta = opts.metaPath and Meta.load(opts.metaPath) or nil
+
+if meta and opts.buy then
+  local success, message = Meta.purchase(meta, opts.buy)
+  io.write(message, "\n")
+  if not success then os.exit(1) end
+end
+
+local game = opts.load and Game.load(opts.load)
+  or Game.new(opts.seed, { class = opts.class, meta = meta, graves = meta and meta.graves, mutators = opts.mutators })
 
 for _ = 1, opts.auto do
   if not game.player:isAlive() then break end
   game:autoStep()
 end
 
+if opts.play then
+  playLoop(game)
+else
   io.write(game:render(), "\n")
+end
+
+if meta and opts.auto > 0 and (not game.player:isAlive() or game.won) then
+  local stats = game:metaStats()
+  local gained = Meta.renownFor(stats)
+  local unlocked = Meta.recordRun(meta, stats)
+  io.write(string.format("run recorded: +%d renown (total %d)\n", gained, meta.renown))
+  for _, name in ipairs(unlocked) do
+    io.write("achievement unlocked: " .. name .. "\n")
+  end
+  local report = Morgue.build(game, meta)
+  local score = Morgue.score(report)
+  local percentile = Analytics.percentile(meta.leaderboard, score)
+  local rank = Leaderboard.record(meta.leaderboard, {
+    score = score, className = report.className, depth = report.deepestDepth,
+    turn = report.turn, won = report.won, seed = game.seed,
+  })
+  if rank then
+    io.write(string.format("leaderboard: rank #%d with score %d (beat %.0f%% of prior runs)\n",
+      rank, score, percentile * 100))
+  end
+end
+
+if meta and opts.auto > 0 and not game.player:isAlive() then
+  Graves.record(meta, game:graveEntry())
+  io.write(string.format("a grave is left at depth %d\n", game.deepestDepth))
+end
+
+if meta then
+  Meta.save(meta, opts.metaPath)
+end
+
+if opts.exportPath then
+  local file = io.open(opts.exportPath, "w")
+  file:write(Export.leaderboardCsv(meta and meta.leaderboard or Leaderboard.new()))
+  file:close()
+  io.write("leaderboard exported to " .. opts.exportPath .. "\n")
+end
+
+if opts.exportCompendiumPath then
+  local file = io.open(opts.exportCompendiumPath, "w")
+  file:write(Export.compendiumCsv(meta and meta.compendium or Compendium.new()))
+  file:close()
+  io.write("compendium exported to " .. opts.exportCompendiumPath .. "\n")
+end
+
+if opts.report then
+  reportMeta(meta or Meta.new())
+end
+
+if opts.verify and not opts.load then
+  if meta then
+    io.write("replay skipped: verification only covers meta-free runs (see replay.lua)\n")
+  else
+    local report = Morgue.build(game)
+    local matches, mismatchField, score =
+      Replay.verify(opts.seed, { class = opts.class, mutators = opts.mutators }, opts.auto, report)
+    if matches then
+      io.write(string.format("replay verified: seed %d reproduces this run (score %d)\n", opts.seed, score))
+    else
+      io.write(string.format("replay mismatch at '%s': seed %d replayed to a different outcome (score %d)\n",
+        mismatchField, opts.seed, score))
+    end
+  end
+end
 
 if opts.save then
   game:save(opts.save)
   io.write("saved to " .. opts.save .. "\n")
 end
+
+if opts.morguePath and (game.won or not game.player:isAlive()) then
+  local report = Morgue.build(game, meta)
+  local file = io.open(opts.morguePath, "w")
+  file:write(Morgue.format(report))
+  file:close()
+  io.write(string.format("morgue written to %s (score %d)\n", opts.morguePath, Morgue.score(report)))
+end
+
+if challengePreset and opts.auto > 0 then
+  local satisfied, reason = Challenges.satisfiedBy(challengePreset, game)
+  if satisfied then
+    io.write("challenge honored: every requirement was active for this run\n")
+  else
+    io.write("challenge broken: " .. reason .. "\n")
+  end
+end