Caster Levels for Multi-Class characters

[Alizee8a]

I have a question about Caster Levels when you multi-class. If you have, for example 2 Bard/2 Wizard, is your caster level 4 when calculated for overcoming a monsters spell resistance since they are both Arcane casters? What about other combos like Wizard/Sorcerer or even crossing to the Divine school? Not that I am planning on making a Wizard/Clerc, but would the "caster level" be considered a collective (or stacked) number?

[Seosamh]

Not sure, but as far as I'm concerned multi-classing a caster is a no-no.

[xoowak]

They don't stack. A 7 sorc/5 wizard will cast his sorc spells at level 7 and his wizard spells at level 5. This is why mixing casting classes is rarely, if ever, a good idea.

[Alizee8a]

Thanks. That's what I thought.