"/level (D)"

[yrudoy]

Some spells have a duration which is per level; i.e. "1 round/level (D)" or "1 minute/level (D)". Is the level referred to here caster level or character level?

[Jarian]

Unless otherwise specified, all level-dependent variables and durations in a spell are based on caster level.

[Douglas]

Caster level. Any time you're talking about spells and the level of the caster, unless specifically noted otherwise it's caster level.

[Cog]

There are a very few exceptions, but they're explicit about it. For example, Dimension Leap works off character level for House Orien (Eberron) favored/marked characters.

[yrudoy]

Thanks!

Also, I have a question about bonus spell slots. If a caster's spell casting attribute changes at some point (for example, from equipment of potions), do they get bonus the spells?
Similarly, what happens if their attribute goes down (from something like ray of stupidity)? Do they immediately lose spell slots and prepared spells?

[Yuki Akuma]

Yup. Sucks to have your casting stat drained.

You only get bonus spell slots for an artificially higher attribute if the bonus has been on for at least a day. So it you wear your ehadband constantly and never take it off, sure! If you always cast Persistent Fox's Cunning at the same time every day (well, actually, better to do it a minute earlier each day, or cast it twice a day)? Sure! Cast Fox's Cunning before going to bed? No.

[Taelas]

Incidentally, the '(D)' in the line means that the spell can be voluntarily dismissed - it has no influence otherwise.

Also, Fox's Cunning specifically does not let you get bonus spells, so Persisting it won't work.

[Yuki Akuma]

Oh, so it doesn't.

Well, a spell that grants a mental ability score increase and doesn't have the "does not provide bonus spells" clause would provide bonus spells if you had it on for 24 hours prior.