Limbus Company battle mechanics

heads chance =
  50% + Sanity%,
  between 5% and 95%

Sanity runs from -45 to 45, so a unit at 0 flips heads half the time and one at 45 lands 95% of its coins. Units without Sanity, which is most Abnormalities, always flip at 50%. Effects that add heads chance stack on top, inside the same limits.

A skill starts at its base power. Each heads adds that coin's power to the total, or takes it away on the few minus coins, and tails changes nothing. Power never drops below 0.

1. Both skills flip all the coins they have left.
2. The side with the higher offense level adds 1 Clash Power for every full 3 levels it has over the other side's offense level.
3. The higher total wins the exchange and the loser's front coin breaks. A tie breaks nothing.
4. That repeats until one side runs out of coins. The winner then attacks with the coins it still has.

Offense level is the unit's level plus the skill's own offense modifier, plus Offense Level Up and Resonance. Winning also pays off after the clash: each exchange adds 3% to the winner's damage multiplier, so a five-exchange clash is worth +15% on every hit. An unopposed attack gets no such bonus.

damage per coin =
  power × multiplier × bonus

multiplier = 1
  + attack type term
  + sin term
  + level term
  + 20% on a crit
  + 3% per exchange won

bonus = 1
  + Damage Up + Fragile
  − Protection

A resistance above 1 counts in full: Fatal (×2.0) adds 100% and Weak (×1.5) adds 50%. Below 1 it only counts half, so Ineffective (×0.5) takes 25% off, not 50%. The attack type and sin terms are added together rather than multiplied, which makes a hit that's Fatal to both ×3.0 instead of ×4.0.

The level term is (offense level − defense level) ÷ (|difference| + 25). Five levels ahead is +16.7% and 25 ahead is +50%; it gets close to ±100% but never reaches it. Defense level is the target's level plus its defense correction, or its defense skill's level while it's using one.

Crits and the clash bonus go into the same sum, so a crit on a Fatal hit is ×2.2, not ×2.4. Damage Up and Fragile add 10% per Count in the second factor and Protection takes 10% off per Count. The result rounds to the nearest whole number (halves go to the even one), and a coin always deals at least 1, or 5% of its power if that's more.

Every unit has stagger thresholds at set shares of its max HP, each rounded down to a whole HP value. A hit that takes HP to a threshold or below Staggers the unit, and a hit that crosses several thresholds uses them all up.

While a unit is Staggered, every attack type hits it as if its resistance were ×2.0, rising to ×2.5 at Staggered+ and ×3.0 at Staggered++, whatever its usual resistances are. Some passives and E.G.O Gifts switch this off for a unit.

Tremor Burst raises the next threshold the unit hasn't reached by the Tremor's Potency in HP, so it staggers that much sooner. The burst doesn't spend the Potency.

186 of 189 identities gain Sanity the same way: +10 for winning a clash plus 20% for each exchange after the first, +10 for defeating an enemy of their level or higher, and +5 when an ally does. They lose 10 when an ally of their level or higher dies. Gains round to the nearest whole number.

Sanity matters because it sets heads chance, and below 0 it starts to risk E.G.O corrosion. The Sanity calculator has every identity's numbers.

An E.G.O used at 0 Sanity or below can corrode. The game measures how far Sanity has fallen toward -45 and checks it against the E.G.O's table, and every E.G.O that corrodes uses the same one: nothing down to -22, then 25%, 75% from -34, and certain corrosion at -45.