[sergex]

Ya it's hard to tell. You'd think that Phoenix Pyre would be fire damage since it takes Fire magic to cast and makes flames when when it goes off, but fire immune units still die to it. Doesn't seem to be much rhyme or reason to it, so I can't really help you. Would seem logical that it would be based on what paths are necessary to cast, but then you have some spells that take 2 paths, like Acid spells so there don't seem to be any set rules.

That would make for a good FAQ.