This material is Open Game Content, and is licensed for public use under the terms of the Open Game License v1.0a.
Every character has six basic Ability Scores:
The Score of these Abilities ranges from 0 to infinity. A limit, if any, will be specified in the rules. The normal human range is 3 to 18. It is possible for a creature to have a score of "none". A score of "none" is not the same as a score of "0". A score of "none" means that the creature does not possess the ability at all. The modifier for a score of "none" is +0.
STR 0 means that the character cannot move at all. He lies helpless on the ground.
DEX 0 means that the character cannot move at all. He stands motionless, rigid, and helpless.
CON 0 means that the character is dead.
INT 0 means that the character cannot think and is unconscious in a coma like stupor, helpless.
WIS 0 means that the character is withdrawn into a deep sleep filled with nightmares, helpless.
CHA 0 means that the character is withdrawn into a catatonic, coma like stupor, helpless.
Keeping track of negative ability score points is never necessary. A character’s ability score can’t drop below 0.
Each ability will have a modifier. The modifier can be calculated using this formula:
(ability/2) -5 [round result down]
The modifier is the number you add to or subtract from the die roll when your character tries to do something related to that ability. A positive modifier is called a bonus, and a negative modifier is called a penalty.
Any creature that can physically manipulate other objects has at least 1 point of Strength.
A creature with no Strength score can't exert force, usually because it has no physical body or because it doesn't move. The creature automatically fails Strength checks. If the creature can attack, it applies its Dexterity modifier to its base attack instead of a Strength modifier.
Any creature that can move has at least 1 point of Dexterity.
A creature with no Dexterity score can't move. If it can act, it applies its Intelligence modifier to initiative checks instead of a Dexterity modifier. The creature fails all Reflex saves and Dexterity checks.
If a character's Constitution changes
enough to alter his or her Constitution modifier, his or her hit points also
increase or decrease accordingly at the same time.
Any living creature has at least 1 point of Constitution.
A creature with no Constitution has no body or no metabolism. It is immune to any effect that requires a Fortitude save unless the effect works on objects. The creature is also immune to ability damage, ability drain, and energy drain, and always fails Constitution checks.
Any creature that can think, learn, or remember has at least 1 point of Intelligence.
A creature with no Intelligence score is an automaton, operating on simple instincts or programmed instructions. It is immune to all mind-influencing effects (charms, compulsions, phantasms, patterns and morale effects) and automatically fails Intelligence checks.
Wisdom
Any creature that can perceive its environment in any fashion has at least 1 point of Wisdom.
Anything with no Wisdom score is an object, not a creature. Anything without a Wisdom score also has no Charisma score, and vice versa.
Charisma
Any creature capable of telling the difference between itself and things that are not itself has at least 1 point of Charisma.
Anything with no Charisma score is an object, not a creature. Anything without a Charisma score also has no Wisdom score, and vice versa.
CHANGING ABILITY SCORES
Ability scores can increase with no limit.
Poisons, diseases, and other effects can temporarily harm an ability (temporary ability damage). Ability points lost to damage return on their own, typically at a rate of 1 point per day.
Some effects drain abilities, resulting in a permanent loss (permanent ability drain). Points lost this way don't return on their own.
As a character ages, some ability scores go up and others go down.
When an ability score changes, the modifier associated with that score also changes.