Ability Damage

Some monsters can cause ability damage, which penalizes one or more of your ability scores. This can add up quickly, so you need to track the total ability damage you’ve taken to each ability score.

For every 2 damage you take to an ability score, reduce your ability modifier by 1 for skills and other statistics affected by that ability. If your total damage to one ability is equal to your score in that ability, you cease taking damage to that ability score, but you fall unconscious until the amount of damage is less than your score. However, if you take Constitution damage that equals your Constitution score, you instead immediately die.

You recover from ability damage to each affected ability score at a rate of 1 per day. Spells such as lesser restoration can also heal ability damage.

Reductions to your ability score modifier from ability damage affect skill checks and ability checks that use that ability score, as well as on the DCs of spells and other abilities based on that score. If you take damage to your key ability score, you also lose 1 RP for every 2 damage you have taken to that ability score. The entries below describe other rolls affected by the reduced modifier.

Strength: Attack rolls that rely on Strength (usually melee or thrown) and weapon damage rolls that rely on Strength (usually melee or thrown).
Dexterity: Armor Class, attack rolls that rely on Dexterity (usually ranged), initiative checks, and Reflex saves.
Constitution: Fortitude saves. You also lose a number of Stamina Points equal to your level for every 2 damage you have taken to Constitution. For example, if you’re 4th level and you took 5 Constitution damage, you’d lose 8 SP.
Wisdom: Will saves.