victorysaber said:
Is there any spell that decreases Energy Resistance or removes Energy Immunity?
If there were such a spell, what level should it be, or should it be epic?
One approach is to use spells that do not rely on energy attacks or only partially rely on energy for damage. For example, ice storm drops large chunks of ice that does 2d6 of cold damage and 3d6 points of bludgeoning damage.
The Spell Compendium has some spells, such as Light of Lunia, that do not rely on a specific energy attack Energy speres, 4th level spell, does acid, cold, electicity, fire, and sonic damage. Vortex of Teeth does 3d8 of force damage and some other spells do damage without using one of the standard energy types.
Another option is to take feats that allow you to substitute one form of energy for another or to rely on energy attacks appropriate to a creature. For example, I recall that relatively few creatures have immunity to sonic attacks or force attacks. Of course, knowing an opponent's strength and weaknesses helps.
Conjured creatures and buffing allies can also be good tactics in handling creatures that are resistant to energy attacks. Plus, conjured creatures can be used to help give allies flanking bonuses.
I hope that these suggestions help.
