Ability Score Bonuses And Damage

Ability Score Bonuses

Some spells and abilities increase your ability scores.
Ability score increases whose duration is 1 day or less give only temporary bonuses. For every two points of increase to a single ability, apply a +1 bonus to the skills and statistics listed with the relevant ability.

Strength
Increases to your Strength score give you a bonus on Strength-based skill checks, melee attack rolls, and weapon damage rolls (if they rely on Strength). The bonus also applies to your combat maneuver bonus, both to perform manuevers and to resist them.
Dexterity
Increases to your Dexterity score give you a bonus on Dexterity-based skill checks, ranged attack rolls, initiative checks, and Reflex saving throws. The bonus also applies to your Armor Class.
Constitution
Increases to your Constitution score give you a bonus on your Fortitude saving throws. In addition, multiply your total Hit Dice by this bonus and add that amount to your current and total hit points. When the bonus ends, remove this total from your current and total hit points.
Intelligence
Increases to your Intelligence score give you a bonus on Intelligence-based skill checks. This bonus also applies to any spell DCs based on Intelligence.
Wisdom
Increases to your Wisdom score give you a bonus on Wisdom-based skill checks and Will saving throws. This bonus also applies to any spell DCs based on Wisdom.
Charisma
Increases to your Charisma score give you a bonus on Charisma-based skill checks. This bonus also applies to any spell DCs based on Charisma.

Ability bonuses with a duration greater than 1 day actually increase the relevant ability score after 24 hours.

Modify all skills and statistics related to that ability. This might cause you to gain skill points, hit points, and other bonuses. These bonuses should be noted separately in case they are removed.

Ability Score Damage and Ability Drain

Diseases, poisons, spells, and other abilities can all deal damage directly to your ability scores. This damage does not actually reduce your ability, but it does apply a penalty to many of the skills and statistics that are based on that ability.

For every two points of damage you take to a single ability, apply a –1 penalty to skills and statistics listed with the relevant ability. If the amount of ability damage you have taken equals or Exceeds your ability score, you immediately fall unconscious until the damage is less than your ability score. The only exception to this is your Constitution score. If the damage to your Constitution is equal to or greater than your Constitution score, you die.

Unless otherwise noted, damage to your ability scores is healed at the rate of 1 per day to each ability score that has been damaged.

Some spells and abilities cause you to take an ability penalty for a limited amount of time. While in effect, these penalties function just like ability damage, but they cannot cause you to fall unconscious or die. In effect, penalties cannot decrease your ability score to less than one.

Strength
Damage to your Strength score causes you to take penalties on Strength-based skill checks, melee attack rolls, and weapon damage rolls (if they rely on Strength). The penalty also applies to your combat maneuver bonus.
Dexterity
Damage to your Dexterity score causes you to take penalties on Dexterity-based skill checks, ranged attack rolls, initiative checks, and Reflex saving throws. The penalty also applies to your Armor Class.
Constitution
Damage to your Constitution score causes you to take penalties on your Fortitude saving throws. In addition, multiply your total Hit Dice by this penalty and subtract that amount from your current and total hit points.
Intelligence
Damage to your Intelligence score causes you to take penalties on Intelligence-based skill checks. This penalty also applies to any spell DCs based off Intelligence.
Wisdom
Damage to your Wisdom score causes you to take penalties on Wisdom-based skill checks and Will saving throws. This penalty also applies to any spell DCs based off Wisdom.
Charisma
Damage to your Charisma score causes you to take penalties on Charisma-based skill checks. This penalty also applies to any spell DCs based off Charisma.

Ability drain actually reduces the relevant ability score.

Modify all skills and statistics related to that ability. This might cause you to lose skill points, hit points, and other bonuses. Ability drain can be healed through the use of spells such as restoration.