Corruption

Corruption is built into the act worlds — it is not a setting. World 7 is the exception: it never gains Corruption at all and stays at C0 for its whole depth. The ladder begins in World 8, which enters at C1, and every later act world enters one tier higher. From there the level climbs by 1 every 300 waves — on entering waves 301, 601, 901… — up to the C24 cap. It cannot be lowered, paused or turned off. Corruption itself adds no enemy-HP multiplier; normal HP scaling from the world and wave still applies.

What each level does

• Enemy damage is multiplied by 1 + 0.35 × C - every enemy attack, projectile and damaging boss ability is scaled
• Every enemy, bosses included, gains +1% dodge per level (C24 → +24%); the Echolocation companion power suppresses it like any other dodge
• Player HP healing is divided by 1 + 0.25 × C; revives and shield restoration are not healing
• From C13 up, regeneration is cut a second time. This covers passive HP regen and healing auras only, never lifesteal or the kill heal. At C24 regeneration keeps 3.57% of its raw rate, the kill heal 14.3% and lifesteal 7.43%, before other modifiers
• In Worlds 7+, raw damage reduction is capped at 90%. The first 75% is safe; only the excess is divided by 1 + 0.25 × C (90% becomes 87% at C1, 78.75% at C12 and 77.14% at C24)
• 0.6% × C of shield-absorbable enemy damage goes directly to HP before shield, damage reduction and armor. This reaches 7.2% at C12 and 14.4% at C24, capped at 2% max HP per hit or per second for continuous damage
• Your damage based on enemy max HP (Fire Nova, Boss Bleeder) is divided by 1 + 0.075 × C (C24 → ÷2.8); Boss Bleeder's drop-chance bonus is unaffected
• A successful material drop gains +6% expected quantity per level through stochastic rounding; a boss uses the level it spawned at. Drop chance and coin rewards are unchanged, except the Sparks chance, which grows with each level
• In new runs, enemies ignore 2% × C of companion slows, stuns, Freeze and dodge suppression (companion auras), up to 48% at C24. This applies in Worlds 8+ above C0 and in Trials on any world; C0 gives 0%.

Corruption Echo

• Lifesteal restores health immediately. Echo then turns a fraction of the HP actually restored into a debt; actual shield gained from Lifesteal Aura overflow counts too. Wasted overhealing does not create debt.
• The debt is deducted gradually from HP. It bypasses armor, shields, dodge and drain resistance, can kill you, and persists after enemies die. Ordinary regeneration does not create Echo.
• Each new lifesteal restoration adds debt and refreshes its repayment window. The total outstanding debt cannot exceed your maximum HP. At C24, restoring 100 HP adds 24 HP of debt over up to 3 seconds.
• The Wraithform ring prevents new debt during phasing but does not erase debt already owed.
• In new runs, a successful Blood Oath rescue clears all existing Echo debt. Its price remains: 1 HP, a shattered shield and 10 seconds without healing or shield recovery.

Echo by Corruption level

Cold

• Chill: Corruption slows your weapon attacks by 1% per level (24% at C24)
• Brittle: while your shield is broken or empty you take 1% more enemy damage per level (24% at C24)
• Shatter: some Brittle enemies explode when they die inside your melee reach - the Rimebound pack's middle member, a broken World 11 formation, a thermal-shocked World 12 body. The blast hurts only YOU, grows +2.5% per level and never takes more than 12% of your HP + shield per hit. Kill these carriers at range
• Your own freezes (the Frostbite companion power, the Permafrost Sigil ring) make enemies brittle for your Glacial Verdict amulet, but freezing alone does not arm a Shatter against you; triggering World 12 thermal shock still arms that world hazard

Corruption levels

How Corruption rises

• The rise lands on ENTERING wave 301 / 601 / 901… - the wave-300 boss always spawns at the old level
• The HUD Corruption badge always shows the current level and the exact wave of the next rise
• World 8 reaches C24 at wave 6901; World 9 at wave 6601