Large red dragon mini with only 5 fire resist...

[Derren]

Oh, I forgot something. According to the dragon combat report dragons can also surround them with a aura of energy (fire in the case of a read dragon), so its not only the mouth which needs to be protected against fire.

 

[FourthBear]

Oh, I forgot something. According to the dragon combat report dragons can also surround them with a aura of energy (fire in the case of a read dragon), so its not only the mouth which needs to be protected against fire.

That indicates that the dragon has some form of pyrokinesis. If it can control fire in that way, it could definitely be deliberately controlling its own flames in a way that it cannot do for another's flames. I recall a comic book character named Pyro who could control flames, but had no particular invulnerability to flames he was not actively controlling. That's another idea for flame breathing dragons that do not have fire immunity.

 

[Merlin the Tuna]

Likewise the Bombadier beetles use chemicals and not actual fire. They also don't spit this out of their mouths.

Your reasoning is absolutely shoddy here. Whether it gets fired from a mouth or a butt makes absolutely no difference -- it's leaving the body from a single point, and only that single point needs to be capable of dealing with the chemicals. And the chemicals fired by the beetle kill creatures through regular old burns, not chemical burns. They're stored separately in the body and, when mixed during firing undergo a reaction which releases a large amount of heat. Whether there's a visible flame or not is entirely irrelevant. Heat is heat.

Everything exists within a certain spectrum. With insufficient Vitamin A, humans go blind and suffer from a weakened immune system. With too much Vitamin A, we become insomniacs with brittle bones. There's such a thing as too much of anything.

 

[Derren]

Except that the magical creatures in D&D, be it red dragon or fire elemental don't use chemicals as the beetle but actual elemental fire. So to store this fire the bodies need to be resistant to it (unlike the body of the beetle where the stuff isn't really harmful until it leaves the body).

Also the mouth is quite more delicate than a body opening which is specifically made for shooting fire as there is a lot more soft tissue present like the tongue and the breathing system is also pretty close.

 

[FourthBear]

Except that the magical creatures in D&D, be it red dragon or fire elemental don't use chemicals as the beetle but actual elemental fire. So to store this fire the bodies need to be resistant to it (unlike the body of the beetle where the stuff isn't really harmful until it leaves the body).

Actually instead of storing this fire, they could be spontaneously generating it, much as mage does when he casts fireball. They could also be living gates to the Elemental Plane of Fire for brief periods, in order to generate fire. Also, "stored" fire could be quite a bit more harmless to the dragon than the active form. Or they could store the fire in a special organ of the body that is much more highly resistant to flame than the rest of the body.

 

[Merlin the Tuna]

Also the mouth is quite more delicate than a body opening which is specifically made for shooting fire...

I will believe this as soon as you try to chew a tortilla chip with your butt hole.

 

[Mouseferatu]

I will believe this as soon as you try to chew a tortilla chip with your butt hole.

Game, thread, and match to the Tuna in the pointy cap.

 

[bgaesop]

Your logic is simply faulty. People drown in water but that doesn't mean that the water does kill them. The lack of air is which does.
You call it semantics but that is a important difference. Exchange the water with any other liquid and you have the same result. Drowning is not more lethal when the substance you drown in is water.

And a fire elemental won't be harmed by wading around in a forest fire, only when something like a red dragon breathes on it (the equivalent of a firehose shooting water at a human).

 

[IanB]

Our stomachs are full of acid. This acid can be quite painful if we lose our natural protection to it and develop an ulcer, or it ends up someplace it isn't supposed to be.

It is not far fetched at all to imagine that dragons could have a similar system that lets them safely breathe their breath weapons out without harming themselves, while not being immune to the breath weapon itself on the parts of the body that don't have a protective mucus layer (or whatever.)

 

[Derren]

And a fire elemental won't be harmed by wading around in a forest fire, only when something like a red dragon breathes on it (the equivalent of a firehose shooting water at a human).

That is not the case. The breath of a dragon is more damaging than a campfire because it is hotter, not because there is more force behind it (otherwise it would deal bludgeoning damage).

The firehose harms a person because of pressure, not because the water is more watery.

Our stomachs are full of acid. This acid can be quite painful if we lose our natural protection to it and develop an ulcer, or it ends up someplace it isn't supposed to be.

It is not far fetched at all to imagine that dragons could have a similar system that lets them safely breathe their breath weapons out without harming themselves, while not being immune to the breath weapon itself on the parts of the body that don't have a protective mucus layer (or whatever.)

The human body is not designed to expel this acid or even surround itself with it. If it would you can bet that we would be quite a lot more resistent to this kind of acid than now (when humans could create a "aura of acid" as some dragons can this protective layer would cover the whole body).