As your character advances in level, he may add new classes to his repertoire. This gives him a broader range of abilities at the expense of progressing — and reaching maximum level — in any of his other classes. You might find this a helpful way to round your character out or better match your concept. For example, your Scientist might gain a level in the Soldier class to increase his fighting skills or show that he’s more of a field operative. When your character possesses levels in two or more classes, the following rules apply.
Base Attack Bonus, Saving Throw Bonuses, Defense Bonus, Initiative Bonus, Wealth, and Gear Picks: Each of these statistics is determined by simply adding together the numbers provided by each of the character’s Class Levels.
Attribute Increases, Feats, and Starting Action Dice: As shown on Table 1.3, your character gains these increases according to his Career Level, regardless of individual Class Levels.
Vitality: You must randomly determine your character’s vitality points for every level of his second and each subsequent class (even the first level of each of these classes). A character only gains maximum possible vitality points at his first Career Level.
Skills: Your character gains the number of skill points listed for “each additional level” of his second and each subsequent class (even the first level of each of these classes). A character only gains quadruple skill points at his first Career Level. These points are spent 1:1 on class skills and 2:1 on cross-classed skills as determined by the class granting the skill points.
Core Abilities: Your character only gains the core ability of his first base class and his first expert class. The core abilities of all other classes in which he gains levels are ignored.
Class Abilities: Except for restricted core abilities, a character gains access to all abilities offered by all of his class levels. In some cases, the effects of these abilities stack; in others, they don’t. Specific instructions are provided in each ability description, and under Legacy Abilities (see page 29).
Special Note: There are no experience point penalties for multi-classing in Spycraft 2.0.