diff --git a/tests/run.lua b/tests/run.lua
index 0d06528..1b841d3 100644
--- a/tests/run.lua
+++ b/tests/run.lua
@@ -3070,6 +3070,179 @@ function tests.nodesHarvestingAGemSeamYieldsARawTierOneGemOfItsElement()
   eq(#game.player.inventory, 1, "a gem lands in the inventory")
   local gem = game.player.inventory[1]
   eq(gem.kind, Items.GEM, "the yield is a gem item")
+  eq(gem.element, Crafting.FIRE, "the gem matches the seam's own element")
+  eq(gem.tier, 1, "a freshly pried gem is raw, tier one")
+end
+
+function tests.nodesGoingFallowRefusesFurtherHarvestsUntilItReopens()
+  local node = Nodes.new(Nodes.ORE)
+  node.charges = 1
+  local game = nodeGame(9)
+  ok(Nodes.harvest(game, node), "the last charge still pays out")
+  eq(node.charges, 0, "spending the last charge empties the vein")
+  eq(node.cooldown, Nodes.REGEN_TURNS, "emptying a vein starts its regen cooldown")
+  local success, line = Nodes.harvest(game, node)
+  eq(success, false, "a fallow vein refuses to be harvested again")
+  ok(contains(line, "played out"), "the refusal is logged")
+end
+
+function tests.nodesStepCountsDownAndReopensAFallowNode()
+  local level = { nodes = { Nodes.new(Nodes.ORE) } }
+  local node = level.nodes[1]
+  node.charges = 0
+  node.cooldown = 2
+  Nodes.step(level)
+  eq(node.cooldown, 1, "each step counts the cooldown down by one")
+  eq(node.charges, 0, "the vein stays fallow until its cooldown reaches zero")
+  Nodes.step(level)
+  eq(node.cooldown, 0, "the cooldown reaches zero on schedule")
+  eq(node.charges, Nodes.MAX_CHARGES, "reaching zero cooldown fully reopens the vein")
+end
+
+function tests.nodesFieldsSurviveSerialization()
+  local level = arena(21, 11)
+  local node = Nodes.new(Nodes.GEM, Crafting.FROST)
+  node.x, node.y = 4, 4
+  node.charges = 1
+  node.cooldown = 5
+  level.nodes = { node }
+  local restored = Level.fromData(level:toData())
+  eq(#restored.nodes, 1, "the node list survives a round trip")
+  eq(restored.nodes[1].kind, Nodes.GEM, "a node's kind survives a round trip")
+  eq(restored.nodes[1].element, Crafting.FROST, "a node's element survives a round trip")
+  eq(restored.nodes[1].charges, 1, "a node's charges survive a round trip")
+  eq(restored.nodes[1].cooldown, 5, "a node's cooldown survives a round trip")
+end
+
+function tests.nodeRendersItsGlyphWhenVisible()
+  local rendered = stagedGame(1, arena(21, 11), 3, 6)
+  local ore = Nodes.new(Nodes.ORE)
+  ore.x, ore.y = 5, 6
+  rendered.level.nodes = { ore }
+  rendered:computeVisible()
+  ok(contains(rendered:render(), "O"), "an ore vein on a visible cell renders as its glyph")
+end
+
+function tests.gameHarvestNodeAtAnOreVeinAddsEssenceAndSpendsACharge()
+  local game = stagedGame(1, arena(21, 11), 5, 5)
+  local ore = Nodes.new(Nodes.ORE)
+  ore.x, ore.y = 5, 5
+  game.level.nodes = { ore }
+  local before = game.player.essence
+  ok(game:harvestNode(), "harvesting the ore vein underfoot succeeds")
+  ok(game.player.essence > before, "harvesting an ore vein raises the player's essence")
+  eq(ore.charges, Nodes.MAX_CHARGES - 1, "harvesting spends one of the vein's charges")
+end
+
+function tests.gameHarvestNodeFailsWithoutANodeUnderfoot()
+  local game = stagedGame(1, arena(21, 11), 5, 5)
+  ok(not game:harvestNode(), "harvesting empty ground fails")
+end
+
+function tests.gameHarvestNodeOnAFallowVeinFails()
+  local game = stagedGame(1, arena(21, 11), 5, 5)
+  local ore = Nodes.new(Nodes.ORE)
+  ore.x, ore.y, ore.charges = 5, 5, 0
+  game.level.nodes = { ore }
+  ok(not game:harvestNode(), "a fallow vein cannot be harvested")
+end
+
+function tests.autopilotHarvestsAnOreVeinWhenIdleAndStandingOnIt()
+  local game = stagedGame(1, arena(21, 11), 5, 5)
+  local ore = Nodes.new(Nodes.ORE)
+  ore.x, ore.y = 5, 5
+  game.level.nodes = { ore }
+  local before = game.player.essence
+  game:choosePlayerAction()
+  eq(ore.charges, Nodes.MAX_CHARGES - 1, "the autopilot harvests an unspent vein it stands on")
+  ok(game.player.essence > before, "the autopilot's harvest actually pays out essence")
+end
+
+function tests.autopilotSkipsAFallowNode()
+  local game = stagedGame(1, arena(21, 11), 5, 5)
+  local ore = Nodes.new(Nodes.ORE)
+  ore.x, ore.y, ore.charges = 5, 5, 0
+  game.level.nodes = { ore }
+  game:choosePlayerAction()
+  eq(ore.charges, 0, "the autopilot never touches a fallow node")
+end
+
+function tests.buildersNeverPlaceANodeOnTheEntranceFloor()
+  for seed = 1, 5 do
+    local level = Builder.build(1, Rng.new(seed), {})
+    eq(#level.nodes, 0, "no resource node appears on the entrance floor")
+  end
+end
+
+function tests.buildersAlwaysPlaceAtLeastOneNodeFromDepthTwoOn()
+  for seed = 1, 5 do
+    for depth = 2, 5 do
+      local level = Builder.build(depth, Rng.new(seed), {})
+      ok(#level.nodes >= 1, "every depth-2-and-deeper floor places at least one resource node")
+      ok(#level.nodes <= 2, "no floor places more than two resource nodes")
+      for _, node in ipairs(level.nodes) do
+        ok(node.kind == Nodes.ORE or node.kind == Nodes.GEM, "every placed node is a known kind")
+      end
+    end
+  end
+end
+
+local function corpsePlayer()
+  return { inventory = {}, statuses = {} }
+end
+
+function tests.corpsesSpawnsForAWildMonsterButNotForUndeadMimicOrBoss()
+  local level = { corpses = {} }
+  local rat = Monsters.create(Monsters.byKey.rat, 1, 5, 5, 1)
+  Corpses.spawn(level, rat)
+  eq(#level.corpses, 1, "a wild monster leaves a corpse behind")
+
+  local zombie = Monsters.create(Monsters.byKey.zombie, 2, 6, 6, 4)
+  Corpses.spawn(level, zombie)
+  eq(#level.corpses, 1, "an undead monster crumbles to dust, leaving no corpse")
+
+  local mimic = Mimics.reveal(3, 7, 7, 4)
+  Corpses.spawn(level, mimic)
+  eq(#level.corpses, 1, "a mimic was never alive, so it leaves no corpse")
+
+  local warlord = Bosses.create(Bosses.byKey.warlord, 4, 8, 8)
+  Corpses.spawn(level, warlord)
+  eq(#level.corpses, 1, "a boss's own scripted loot drop replaces a corpse")
+end
+
+function tests.corpsesNutritionScalesWithTheFelledSpeciesMaxHpClampedToAFixedBand()
+  local bat = Monsters.create(Monsters.byKey.bat, 1, 5, 5, 1)
+  local batCorpse = Corpses.new(bat)
+  eq(batCorpse.nutrition, Corpses.NUTRITION_MIN, "a frail species clamps to the nutrition floor")
+
+  local troll = Monsters.create(Monsters.byKey.troll, 2, 5, 5, 5)
+  local trollCorpse = Corpses.new(troll)
+  eq(trollCorpse.nutrition, troll.maxHp * Corpses.NUTRITION_PER_HP, "a tougher species scales nutrition with maxHp")
+
+  local dragon = Monsters.create(Monsters.byKey.dragon, 3, 5, 5, 6)
+  local dragonCorpse = Corpses.new(dragon)
+  eq(dragonCorpse.nutrition, Corpses.NUTRITION_MAX, "an especially tough species clamps to the nutrition ceiling")
+end
+
+function tests.corpsesStepCountsDownAndRotsAwayEntirely()
+  local rat = Monsters.create(Monsters.byKey.rat, 1, 5, 5, 1)
+  local level = { corpses = {} }
+  Corpses.spawn(level, rat)
+  local corpse = level.corpses[1]
+  for _ = 1, Corpses.DECAY_TURNS - 1 do Corpses.step(level) end
+  eq(#level.corpses, 1, "a corpse survives right up to its final round")
+  eq(corpse.decay, 1, "decay counts down by exactly one each step")
+  Corpses.step(level)
+  eq(#level.corpses, 0, "a corpse vanishes outright once its decay reaches zero")
+end
+
+function tests.corpsesGoesRottenPastItsThresholdButStaysButcherableUntilThen()
+  local rat = Monsters.create(Monsters.byKey.rat, 1, 5, 5, 1)
+  local corpse = Corpses.new(rat)
+  ok(not Corpses.isRotten(corpse), "a freshly spawned corpse is not yet rotten")
+  corpse.decay = Corpses.ROT_TURNS
+  ok(Corpses.isRotten(corpse), "a corpse right at its rot threshold counts as rotten")
+  corpse.decay = Corpses.ROT_TURNS + 1
 end
 
 local order = {