Hey, I'm running a combat with a 3rd-party non-Paizo monster and I'm slightly confused over the mechanics of it.
The Chelicerae
What I'm hung up on is the description of the 'siphon spell slots' ability:
Chelicerae cannot replenish spell slots naturally and, instead, extract them from the minds of humanoids locked in its mandibles The chelicerae treats the bodies of grappled spellcasters as a spell point reservoir for as long as the grapple is maintained, draining unused spell slots to power the casting of their own spells, 1 point/spell level.
All 0-level spells become at-will abilities. Whenever the chelicerae wishes to cast any one of its spells known, it consumes a number of spell slots from its victim equal to the spell slots necessary to cast the spell (including increased levels for metamagic feats and so on). If the body has insufficient number of spell slots available, the chelicerae cannot cast that spell...
So, let's say a Chelicerae is grappling a 7th-level sorcerer who can only cast 3rd level spells. Does that mean the chelicerae can only cast spells from its spell list of 3rd level and below, and not use its 4th level spell? Or, if the points of all the spell slots the bard had left add up to over 4, can it cast its 4th level spell?