View source for User:MisterSinister/TOToM (3.5e Sourcebook)/SRP4/Magic Overview

== Caster Level ==

A spell's power often depends on its caster level. This is equal to its user's character level under most normal conditions. It is also used for caster level checks, which are resolved by rolling 1d20 and adding the user's caster level.

If a character has levels in more than one spellcasting class, the caster levels for each are independent, but still all equal their character level.