Simple Caster Limitation

[Ashtagon]

Alternatively, limit characters from taking more than half their current character levels in any one full-caster class. Allow a dedicated wizard to take "alternate" wizard" as a second class, a class which has rules identical to the standard wizard but whose spell-casting does not stack with his other wizard class. And ditto for clerics (the cleric's "alternate cleric" class should be of the same deity).

This will of course preclude some of the highest level spells from entering the game pre-epic. And certain prestige classes will need to be reviewed (make them count as levels in the same class that they are stacking their casting ability on).

This will also make some of those "count levels in class X as levels in class Y" feats one of the Complete books more useful from.