Statistic (role-playing Games) - Interdependencies Between Statistics

Interdependencies Between Statistics

Some games define various interdependencies between statistics of different categories, as well as within categories. The most common are:

Prerequisite

Only if statistic A has a value of at least x, statistic B may exceed value y. (Where y is often 0 or none.)

For example, a character class may require certain minimum attribute scores, or a spell may require a minimal level of magical talent. Learning some esoteric skill often requires knowledge of another one at an “expert” level or possession of a certain advantage: In GURPS Martial Arts, for example, “cinematic” or “mystical” martial arts abilities require a special advantage, Trained by a Master.

Limitation

If statistic A has a value of at least x, then statistic B cannot exceed value y.

This is the opposite of prerequisite. (Only if statistic A has a value of at most x, statistic B may exceed value y.) For example, a character class may be disallowed for certain races, or one of the game effects of a disadvantage (say, Unfit), could be to limit a certain attribute (Constitution or Health in the example) to a certain maximum value (no more than average).

Bonus or base value

If statistic A has a value of x, then the value of statistic B is increased by (or starts at) y. The term base value is preferred if y = x or if y is large compared to B's value.

Higher scores in an attribute often grant bonuses to a group of skills.

Derivation

If statistics A and B have values of x and y, respectively, then the value of statistic C is a function of (x, y).

Derived (or secondary) statistics are discussed elsewhere.