oooh, another thought springs to mind... Beings with no water in them by virtue of their composition should also be immune altogether to this spell. examples of which:
Constructs: (other than clay golem... they might crumble perhaps)- draining moisture from iron is pretty ludicrous
Fire Elementals- totally
Earth elementals- can't get blood from a stone, and blood's about 70-80% water
Undead- half damage. You can wilt a zombie or skeleton to make them brittle, but it wouldn't hurt them as much since they don't require the bodily fluids living beings require. (though using this spell on a vampire could make him VERY hungry almost immediately
)
Non Corporeal Beings- Totally immune, they exist on the ethereal plane and even then only as sentient negative energy clusters.
Meanwhile:
Vaporous beings- Nishruu, steam elementals etc: double damage or so. Once you take away their vapor, they're really just a bunch of hot air.
Amphibious beings- Kuotoa, frogs, anything with slippery, squishy skin- either double dmg or -4 to their fort check vs the spell. These beings rely on much more water than other standard living organisms and would be hit by this spell a little more severely
Fogs/mists- probably dispelled at least temporarily. Not really so much a tactical way to use the spell, but may be interesting to use it to RP with the environment. Of course Corath's Red Fog may be more negative energy clouding than water vapor.
Plants- very severe to these types (think the spell may already account for this) Treants, shambling mounds, turnips, assassain vines... all suffer greatly from this spell. Either double dmg or -4 to fort saves.
Also, if you use this spell on a 12 pack of juice, it turns the whole batch into 2 tablespoons worth of concentrated powder... dehydrated milk, Kool Aide or what not
meanwhile if we have the "Drown" spell from PnP, it should totally whack the smoke out of fire elementals. Of course Constructs would be totally immune, and amphibians would get little more than a breath of fresh water. Drown and Horrid Wilting should be decent counterspells. Drown does something like area affect fort save or die, and damage on a fail if I remember correctly. What it essentially does is somewhat the opposite of wilting, it adds water to a being's body, and almost entirely in it's lungs. Since fire elementals don't have lungs, it'd most likely use center mass. Undead, Constructs, rock elementals etc would be totally immune and water elementals might even be boilstered/healed.
