ToME WikiBurbLulls: Certain things can render you vunerable to fire, and Ents are vulnerable too. I think Ent flammability should be different.
Here's the idea; when an Ent is hit by a fire attack, there should be a chance that the fire will keep burning. Ents are tree-beings, and trees burn. This should be like a vicious bout of poison or a cut; more deadly than them. The way to stop it is to quaff a potion of water. Other quaffed potions may put it out but not 100% of the time. Naturally, going into a body of water puts out the fire. This would add some use to water as well!
MayLith: I like that. How about, for each round the fire keeps burning, scrolls in the Ent's pack should save vs. a chance of burning up.
Simon: Leather armors on fire have been problems historically, in real life, in human battles. Paper armor should be ridiculously flammable, too. Perhaps those should reduce fire resistance under the new resistance system?
ErisDiscordia: If the Galleon reward is going to remain the same in 2.3 Release as in the CVS version, then us Ents should definitely be penalized more. I've been running around for quite some time triple-sensitive to fire (Mage Staff of HardToSpell, Stinkin' Duds of the Wight, Enthood) and single-immune, and cackling evilly all the while. Heh heh heh. BOOOOOM!
RavenRed: The only thing I'd add to this is that fire attacks should perhaps act like poison for Ents. See IdeaArchive/A little bit poisoned? for an game mechanics idea that might be transferrable...