Majoru Oakheart
Adventurer
FYI, the reason fire elementals have limited or no resistance to fire was that WOTC didn't want to restrict ideas for characters. And the "Fire Mage" is an archtypical one(The character who took nothing but fire powers). And they didn't want to run into a circumstance where one member of the party felt like they had to sit in a corner and do nothing for a combat(one of the design goals was to eliminate that from every happening, therefore no spells that paralyze people for 10 rounds, no save or dies, no removing people's major class defining features like sneak attack against a large class of enemies and so on). And if the party is fighting Fire Immune Fire Elementals, the Fire Mage has to sit there and watch the combat.
The other reason they gave was that they envisioned wars between armies of fire elementals controlled by different masters. And realized that the war would be kind of pointless, they'd all be completely immune to all the attacks of the other creatures.
The same thing applied to creatures in a cold environment. You'd have Yetis that have resistance to cold because they need to be able to survive in the arctic. But you'd have them hunting other creatures on a regular basis that also had resistance to cold(because they also lived in an arctic climate) meaning that most cold creatures couldn't actually hunt their likely prey. Plus, add to this the archtypical "Cold Wizard" who uses spells that manipulate the forces around him, picking up snow balls and throwing the, forming icicles on people and such. And realize that being an ice mage in the arctic was about the worst thing you could be.
So they settled on the fact that even though an attack was cold or fire or whatever, that it was still magic. And the magic part was more important than what form the magic took. Sure, a fire elemental could be immune to any normal fire. But a Fireball did more than just create a ball of fire, it created a shockwave of magic force that propelled the fire and damaged the "soul" of the creature as well.
The other reason they gave was that they envisioned wars between armies of fire elementals controlled by different masters. And realized that the war would be kind of pointless, they'd all be completely immune to all the attacks of the other creatures.
The same thing applied to creatures in a cold environment. You'd have Yetis that have resistance to cold because they need to be able to survive in the arctic. But you'd have them hunting other creatures on a regular basis that also had resistance to cold(because they also lived in an arctic climate) meaning that most cold creatures couldn't actually hunt their likely prey. Plus, add to this the archtypical "Cold Wizard" who uses spells that manipulate the forces around him, picking up snow balls and throwing the, forming icicles on people and such. And realize that being an ice mage in the arctic was about the worst thing you could be.
So they settled on the fact that even though an attack was cold or fire or whatever, that it was still magic. And the magic part was more important than what form the magic took. Sure, a fire elemental could be immune to any normal fire. But a Fireball did more than just create a ball of fire, it created a shockwave of magic force that propelled the fire and damaged the "soul" of the creature as well.