Q 146: Is there any rule, official ruling, or ability that explicitly states that you can or can't deal both fire and ice damage with the same attack/weapon/spell? My DM is being something of a prick on pairing quickflame with quickfrost.
Only as far as weapon enhancements are concerned (I think pretty much all of them state you can't have one of Flaming/Shocking/Frost/Sonic/Acid enhancements on the same weapon).
All I need is an official source either saying you can do fire and cold damage at the same time (and specifically fire and cold), or some official effect that deals both fire and cold damage at the same time.
Rimefire Witch and Rimefire Eidolon from Frostburn have attacks that deal both fire and cold damage at once.
In 3.0 it was stated that because they were magical in nature, the enhancements (fire/frost/shocking/etc) stacked, but non-magical sources negated each other (standing in a campfire in an area cold enough to deal cold damage, etc), but that was never directly reprinted in 3.5.
Dragonfang weapons deal +1 elemental damage from the big five. It's explicitly mentioned as only stacking with elemental damage of different types - the example given mixes damage types.
The metamagic feat Energy Admixture (CAr, 78) is an explicit example of mixing two (or more) energy types. It even specifically mentions that mixing opposing energy is allowed.
Additionally, there is no such restriction for weapon abilities in either the DMG or MIC. A
+1 flaming frost corrosive shocking longsword should be absolutely legal. The
energy surge weapon property (MIC, 34) gives an example of a weapon that has both the
flaming and
corrosive properties, for instance.