Rule: Ability Scores
To create an ability score for your character, roll four six-sided dice (4d6). Disregard the lowest die roll and total the three highest ones. The result is a number between 3 (horrible) and 18 (tremendous). The average ability score for the typical commoner is 10 or 11, but your character is not typical. The most common ability scores for player characters (PCs) are 12 and 13. (That’s right, the average player character is above average.)
Make this roll six times, recording each result on a piece of paper. Once you have six scores, assign each score to one of the six abilities. At this step, you need to know what kind of person your character is going to be, including his or her race and class, in order to know how best to distribute the ability scores. Choosing a race other than human or half-elf causes some of these ability scores to change (see Table 2–1: Racial Ability Adjustments, page 12 of the Player's Handbook v3.5).
Each ability, after changes made because of race, has a modifier ranging from –5 to +5. Table 1–1: Ability Modifiers and Bonus Spells (on the next page) shows the modifier for each score. It also shows bonus spells, which you’ll need to know about if your character is a spellcaster.
The modifier is the number you apply to the die roll when your character tries to do something related to that ability. For instance, you apply your character’s Strength modifier to your roll when he or she tries to hit someone with a sword. You also use the modifier with some numbers that aren’t die rolls—for example, you apply your character’s Dexterity modifier to his or her Armor Class (AC). A positive modifier is called a bonus, and a negative modifier is called a penalty.
Table: Ability Modifiers and Bonus Spells
|Score||Modifier||Bonus Spells (by Spell Level)|
|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|
|etc. . .|
ABILITIES AND SPELLCASTERS
The ability that governs bonus spells (see Chapter 3: Classes of the Player's Handbook v3.5) depends on what type of spellcaster your character is: 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 high enough class level to be able to cast spells of a given spell level. (See the class descriptions in Chapter 3 (of the Player's Handbook v3.5) for details.) For instance, the wizard Mialee has an Intelligence score of 15, so she’s smart enough to get one bonus 1st-level spell and one bonus 2nd-level spell. (She will not actually get the 2nd-level spell until she is 3rd level wizard, since that’s the minimum level a wizard must be to cast 2nd-level spells.)
If your character’s ability score is 9 or lower, you can’t cast spells tied to that ability. For example, if Mialee’s Intelligence score dropped to 9 because of a poison that reduces intellect, she would not be able to cast even her simplest spells until cured.
If your scores are too low, you may scrap them and roll all six scores again. Your scores are considered too low if the sum of your modifiers (before adjustments because of race) is 0 or lower, or if your highest score is 13 or lower.