Multiclassed Casters, Wondrous Items, and Caster level,

[jabberwocky]

I don't know if this has been covered in the multiple mystic theurge threads, but I don't remeber seeing it, so I'll go ahead and ask.

The question deals with caster level increasing items, such as the ioun stone that gives +1 caster level. If you have multiple casting classes, does it add to both, or just one of those classes? And if it is just one, do you get to choose which it applies to, and is that a permanent choice?

Also, Incense of Meditation - the relevant bit of the SRD says : 'When a divine spellcaster lights a block of incense of meditation and then spends 8 hours praying and meditating nearby, the incense enables him to prepare all his spells as though affected by the Maximize Spell feat.' So does a mystic theurge, or a Cleric 1/Wizard X get to prepare ALL his spells as if they were maximized, even the wizard ones?

The Bead of Karma (on Strand of Prayer Beads) gives a generic +4 caster level when activated. Or the +2 caster level for penetrating spell resistance from the Robes of the Archmagi. Do these apply across all casting classes, or not?

The loophole in the last three items is that they require a specificly arcane or divine caster to be able to activate them, but the effects aren't specified as applying to only one of these divisions. The Ioun Stone doesn't say anything about arcane/divine distinctions at all.

So what do people think the interpretations should be? Would allowing these items to affect multiclassed spellcasters be vastly overpowered, or just a clever use of magic items?

 

[Quez The Lame]

I'd say, if it needs a divine spellcaster, it only affects divine casting. Using Incense of Meditation would only affect the divine capabilities of the character. There wouldn't be any consequences for the arcane part. Sounds kinda scizophrenic, but hey, D&D is an abstract rules system.

For the ioun stone: I'd handle it to be usable only for one kind of spellcasting at any time. When applied you choose wether it enhances arcane or divine spellcasting (or more precisely the exact class to be affected, cause there are more than one arcane/divine spellcasting classes that don't stack).
But I'd allow to choose the class each time the ioun stone is applied. So take it of, put it on and choose another class to use it. That's not official ruling, just my opinion (or let's call it house ruling).

 

[Li Shenron]

Incense of Meditation and Bead of Karma affect only divine spellcasting; if you have more divine spellcasting classes, you get benefits to all of them.

Robe of Archmagi affects only arcane spellcasting; if you have more arcane spellcasting classes, you get benefits to all of them.

Ioun Stones affect all spellcasting; if you have more spellcasting classes, you get benefits to all of them.

It is not explicitly stated by the SRD one way or the other, hence your legitimate doubt. But when about an item it says "if a divine spellcaster does this and that" and gives a spellcasting benefit, I think it is intended to work only on divine spellcasting. If it said "when a druid does this... the item confers that to his spells", we can easily assume it means only to druid spells.