An ability modifier is the bonus or penalty associated with a particular ability score. Ability modifiers apply to die rolls for character actions involving the corresponding abilities -- such as attack rolls, saving throws and skills. The modifier is also used with some numbers that aren't die rolls. A positive modifier is called a bonus, and a negative modifier is called a penalty.
The modifier is equal to +1 for every 2 points above 10 in that ability score (or -1 for every 2 full points below 11). For example, constitution 14 provides +2 hit points per level.
In addition, ability scores determine the number of bonus spells for spellcasters. The ability that spells relate to depends on the type of spellcaster: Intelligence for wizards; Wisdom for clerics, druids, paladins, rangers, and spirit shamans; or Charisma for sorcerers, bards, and favored souls. In addition to having a high ability score, a spellcaster must be of sufficient level in order to gain any bonus spells for a given level. Spellcasters must also have a 10 or higher in the appropriate ability score in order to cast any spells.
Modifier Table
| Score | Modifier/ 2H str dmg mod | Bonus Spells (by Spell Level) | |||||||||
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | ||
| 1 | -5/-5 | Can't cast spells tied to this ability | |||||||||
| 2-3 | -4/-4 | Can't cast spells tied to this ability | |||||||||
| 4-5 | -3/-3 | Can't cast spells tied to this ability | |||||||||
| 6-7 | -2/-2 | Can't cast spells tied to this ability | |||||||||
| 8-9 | -1/-1 | Can't cast spells tied to this ability | |||||||||
| 10-11 | 0/0 | - | - | - | - | - | - | - | - | - | - |
| 12-13 | +1/+1 | - | 1 | - | - | - | - | - | - | - | - |
| 14-15 | +2/+3 | - | 1 | 1 | - | - | - | - | - | - | - |
| 16-17 | +3/+4 | - | 1 | 1 | 1 | - | - | - | - | - | - |
| 18-19 | +4/+6 | - | 1 | 1 | 1 | 1 | - | - | - | - | - |
| 20-21 | +5/+7 | - | 2 | 1 | 1 | 1 | 1 | - | - | - | - |
| 22-23 | +6/+9 | - | 2 | 2 | 1 | 1 | 1 | 1 | - | - | - |
| 24-25 | +7/+10 | - | 2 | 2 | 2 | 1 | 1 | 1 | 1 | - | - |
| 26-27 | +8/+12 | - | 2 | 2 | 2 | 2 | 1 | 1 | 1 | 1 | - |
| 28-29 | +9/+13 | - | 3 | 2 | 2 | 2 | 2 | 1 | 1 | 1 | 1 |
| 30-31 | +10/+15 | - | 3 | 3 | 2 | 2 | 2 | 2 | 1 | 1 | 1 |
| 32-33 | +11/+16 | - | 3 | 3 | 3 | 2 | 2 | 2 | 2 | 1 | 1 |
| 34-35 | +12/+18 | - | 3 | 3 | 3 | 3 | 2 | 2 | 2 | 2 | 1 |
| 36-37 | +13/+19 | - | 4 | 3 | 3 | 3 | 3 | 2 | 2 | 2 | 2 |
| 38-39 | +14/+21 | - | 4 | 4 | 3 | 3 | 3 | 3 | 2 | 2 | 2 |
| 40-41 | +15/+22 | - | 4 | 4 | 4 | 3 | 3 | 3 | 3 | 2 | 2 |
| 42-43 | +16/+24 | - | 4 | 4 | 4 | 4 | 3 | 3 | 3 | 3 | 2 |
| 44-45 | +17/+25 | - | 5 | 4 | 4 | 4 | 4 | 3 | 3 | 3 | 3 |
| 46-47 | +18/+27 | - | 5 | 5 | 4 | 4 | 4 | 4 | 3 | 3 | 3 |
| 48-49 | +19/+28 | - | 5 | 5 | 5 | 4 | 4 | 4 | 4 | 3 | 3 |
| 50-51 | +20/+30 | - | 5 | 5 | 5 | 5 | 4 | 4 | 4 | 4 | 3 |
See also
- Ability score loss
- Ability damage
- Ability cap