[Fordain]

Perception for casters is obvious. Counterspelling... I also think that perception will be based around your class and what you do, that way everyone would be a different (personally, I like this idea but it might just be wishfully thinking...).

A fighters perception is (as was mentioned) a tactical response to a situation. Rogues I can see as having perception for a sneak attack or backstab like ability, or traps etc.

Though my thoughts are along the lines of D&D so they might be all wrong! Excellent thread. Glad I read through it.