diff --git a/src/affixes.lua b/src/affixes.lua
new file mode 100644
index 0000000..8009930
--- /dev/null
+++ b/src/affixes.lua
@@ -0,0 +1,40 @@
+-- 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.
+
+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 } },
+}
+
+Affixes.armor = {
+  { key = "sturdy",     name = "sturdy",     power = 1 },
+  { key = "reinforced", name = "reinforced", power = 2 },
+}
+
+local function roll(pool, rng, chanceNumerator, chanceDenominator)
+  if not rng:chance(chanceNumerator, chanceDenominator) then return nil end
+  return pool[rng:range(1, #pool)]
+end
+
+function Affixes.rollWeapon(rng)
+  return roll(Affixes.weapon, rng, 1, 2)
+end
+
+function Affixes.rollArmor(rng)
+  return roll(Affixes.armor, rng, 1, 3)
+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.power = item.power + affix.power
+  item.name = affix.name .. " " .. item.name
+  return item
+end
+
+return Affixes