SYSTEM REFERENCE DOCUMENT 3.5
Prestige classes offer a new form of multiclassing. Unlike the basic classes, characters must meet Requirements before they can take their first level of a prestige class. The rules for level advancement apply to this system, meaning the first step of advancement is always choosing a class. If a character does not meet the Requirements for a prestige class before that first step, that character cannot take the first level of that prestige class. Taking a prestige class does not incur the experience point penalties normally associated with multiclassing.
Definitions of Terms
Here are definitions of some terms used in this section.
Base Class: One of the standard eleven classes.
Caster Level: Generally equal to the number of class levels (see below) in a spellcasting class. Some prestige classes add caster levels to an existing class.
Character Level: The total level of the character, which is the sum of all class levels held by that character.
Class Level: The level of a character in a particular class. For a character with levels in only one class, class level and character level are the same.