Callum |
Can incorporeal creatures be set on fire (say, by a fire storm spell)? I'm inclined to say that they can catch on fire, but the fire won't damage them.
avr |
Nonmagical fire doesn't harm incorporeal creatures...but being set on fire by a fire storm spell does more damage than being set on fire by normal means. I suspect that means it's magical. It might be just that fire storm tries to ignite more of you than even a forest fire, but I think that in this case you can set ghosts on fire RAW.