Just what the title says: how do temporary HP stack in D&D 3.5 under the rules as written?
I have a way that I run the game, which has worked for me just fine. Based on some other answers here, I am no longer confident that the way I run games matches the canonical rules. I might not adopt any changes based on this answer by, but I do want to understand what the rules actually say.
In general, only different bonus types, from different sources stack. So if I have a spell that gives me an untyped disguise bonus, I can’t double it by casting the spell twice. Similarly, if I have a hat that gives me an enhancement bonus to appraise, I can’t get extra benefit from also wearing boots that give an enhancement bonus to appraise.
Hit points are different though, in that they track a state instead of giving an ongoing bonus. So if I receive two cure light wounds spells, I benefit from both.
How do temporary HP work? If I cast false life twice, do I get double the temporary HP (ignoring the randomness from the dice)? Do the pools somehow overlap, but each eat damage? Overlap, and the smaller one is just lost?
Does that answer change if I cast two different spells?