Characters have a score ranging from 3 to 18 in each of the following abilities below (strength, intelligence, wisdom, dexterity, constitution and charisma). A bonus or penalty is associated with each score, as shown on the table above. Each class has a Prime Requisite ability score as well, which must be at least 9 in order for the character to become a member of that class. There are also required minimum and maximum scores for each character race other than Humans (as described under Character Races).
Strength
As the name implies, strength measures the character's raw physical power and is the prime requisite for fighters (and the associated ability bonus or penalty is applied to all attack and damage rolls in hand to hand combat). Note that a penalty here will not reduce damage from a successful attack below one point.
Intelligence
This is the ability to learn and apply knowledge and is the prime requisite for magic-users.
Wisdom
A combination of intuition, willpower and common sense, wisdom is the prime requisite for clerics. The wisdom bonus or penalty may apply to some saving throws vs. magical attacks, particularly those affecting the target's will.
Dexterity
This ability measures the character's quickness and balance as well as aptitude with tools, and hence is the prime requisite for thieves. The dexterity bonus or penalty is applied to all attack rolls with missile (ranged) weapons, to the character's armor class and to the character's initiative roll during combat.
Constitution
A combination of general health and vitality. The constitution bonus or penalty is applied to each hit die (level) rolled by a character (but a penalty will never reduce hit die rolls below one point).
Charisma
This is the ability to influence people, as those with high charisma are well-liked and respected. Certain shopowners will also sell their wares at a less expense to those with high charisma.
Likewise, characters also possess a collection of behaviors that also range from 3 to 18 (altruism, curiosity, diplomacy, empathy, honor, optimism, reason, spirit and tolerance). These are introduced as follows:
Altruism
Willingness of a character to give of himself, whether materialistically, physically or spiritually.
Curiosity
Measure of a character’s natural desire for knowledge and universal understanding.
Diplomacy
Ability to articulate, work together and generally talk one’s way into (or out of) a situation.
Empathy
Relative open-mindedness of a character and her ability to feel what others around her feel.
Honor
Measurement of the character’s willingness to do the right thing regardless of the circumstances.
Optimism
Degree to which the character sees a situation as positive (the glass is half full).
Reason
Degree of which a character will act according to logic and observed reality instead of tradition and religion.
Spirit
Measure of a character's zest for life and quest to be the center of attention.
Tolerance
Degree to which the character will tolerate disagreeable actions, ideas and behaviors.