Ability modifier

An ability modifier is a number applied to a die roll when doing something related to that ability -- 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 points below 10). 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, and rangers; or Charisma for sorcerers and bards. 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	Bonus Spells (by Spell Level)
		0	1	2	3	4	5	6	7	8	9
1	-5	Can't cast spells tied to this ability
2-3	-4	Can't cast spells tied to this ability
4-5	-3	Can't cast spells tied to this ability
6-7	-2	Can't cast spells tied to this ability
8-9	-1	Can't cast spells tied to this ability
10-11	0	-	-	-	-	-	-	-	-	-	-
12-13	+1	-	1	-	-	-	-	-	-	-	-
14-15	+2	-	1	1	-	-	-	-	-	-	-
16-17	+3	-	1	1	1	-	-	-	-	-	-
18-19	+4	-	1	1	1	1	-	-	-	-	-
20-21	+5	-	2	1	1	1	1	-	-	-	-
22-23	+6	-	2	2	1	1	1	1	-	-	-

See also

• Ability score loss
• Ability damage
• Ability cap