Multiple caster classes - sharing slots?

[weckar]

Is there any way in the game to use spell slots of one class to cast spells given by another? Even if it is limited in some way?

I imagine, for example, being able to use Bard slots for your sorcerer spells or the other way around? Cleric slots for your Shugenja spells?

[Uncle Pine]

The Ultimate Magus PrC can do something like that. It's in Complete Mage if you want to look at it.

[Malimar]

Pathfinder's Mystic Theurge gets the ability to prepare a spell from one class using a spell slot from the other, using a slot 1 higher (as if it were a +1 metamagic).

[Zaq]

I believe that it is against RAI, but there's an argument that Versatile Spellcaster (Races of the Dragon) can use spontaneous slots from class A to cast a spell that you know from class B.

[Uncle Pine]

ShurikVch will probably pop up at some point with an exact issue and page reference, but there is a Dragon Magazine with psionic/arcane theurge stuff that should have a feat you can use to fuel each half of your theurge with the other one (pp/spell slots).

[Malimar]

ShurikVch will probably pop up at some point with an exact issue and page reference, but there is a Dragon Magazine with psionic/arcane theurge stuff that should have a feat you can use to fuel each half of your theurge with the other one (pp/spell slots).

Dragon #349, pp88-89. Several different feats doing this and related things (sacrifice spell for PP, sacrifice PP for spell, sacrifice PP for metamagic reduction, etc).

[ben-zayb]

Vaulnaen (CHA + INT) Illumians can do this by RAW and RAI, but is limited to 2x a day.

[weckar]

Ideally I'd cast a spell known from a spontaneous arcane in a prepared divine slot... Unfortunately Illumians are one of the few things definitively banned at our table.