Caster level effects and long casting times.

[seebs]

Say you have access to Create Demiplane, and you have also a working Strand of Prayer Beads.

The Karma bead gives you a +4 to CL.

If you use it, then start casting a spell with a 6-hour casting time, does it work?

[Jonathan Dempe]

I believe so since at the time of initial casting youre considered 4 levels higher

[seebs]

I can't figure whether it should be when you start casting, when you finish casting, or the whole time that you have to have a given effect up.

[Jonathan Dempe]

Well say your level 16 and you use the karma prayer beads at the time of casting you are effectively level 20 regardless of when the spell resolves it will have began as a spell being cast by a level 20 caster so even if its when you finish you are still resolving a caster level spell of 20

[seebs]

That makes sense, but does anything in the rules ever explicitly state what happens if the duration of a caster-level buff expires during the casting of a spell?

[Jonathan Dempe]

nope sadly not