D&D 5E Dragon's breath weapon vs wall

[Tonguez]

Granite cracks at just over 540 Celsius and melts over 1200 C, so the question is how hot is Dragon Breath.

Id allow for Dragon breath burning at a similar temperature to Napalm (800 - 1200 C) so a sustained (multiple round) attack from a dragon would be enough to crack a stone wall - perhaps 3 or more rounds before the force and weight of the cracked stone causes it to crumble.

 

[Chaosmancer]

First things first, thank you all for your interest. This week has been, and it's going to be very busy for me for life-related issues, but I'll try to answer some comments when I find some time. In the end, my party cheaped out and got wooden walls instead of stone walls, but there's still stone structures for the dragon to attack, so the discussion is still worth it.


On a related note, I planned the dragon to be the final boss of the campaign, but my party, for unrelated reasons to the dragon, is very heavy on fire resistance (the only one without it is the druid, who can get protection from energy), so I realized an adult red dragon may not be enough to make a climactic finale for a party of 4-5 level 15 characters, even with variant spellcasting and an stolen magic item. It's lair has a lot of lava, but still, it would be great to see your opinions.

I've been toying with these ideas: Give it minions, make it ancient (or a homebrew point in between, old or something like that, ancient white dragon level), and give it a secondary breath weapon like that of a metallic dragon that burns away fire defenses (inmunity becomes resistance, resistance becomes nothing and nothing becomes vulnerability). Thoughts?

Minions are the best answer I've found. They really offer so much.

Now, that being said, this is a final boss, so homebrew is completely worth it. I'd give it some sorcerer levels (after all, Dispel Magic makes so much sense for a creature who adventures often get Fire resistance, or that Elemental break spell, that removes resistance)

Additionally, give it something unique. Fire Aura? The ability to summon gouts of lava from the floor? A breath weapon of smoke and ash to blind the party?

Just one or two things to make it (insert name here) instead of just an Adult Red Dragon.

 

[aco175]

Powering up a dragon is easy. You can always give out wizard levels and change some lair powers. You can have something that changes the breath weapon to cold or lightning. I would likely give the PCs a fire breath before the dragon realizes they all have resistance before changing it. You can also have dragon allies spy on the PCs and then the dragon knows things before hand, depending on how you play the dragon, in that it can be more a mob boss and control a lot of smaller groups or if it is a loner and hides in its mountain.

 

[Hoffmand]

In my games I just assume dragon breath is the hottest thing in existence. Well hotter than the center of the sun. It really just depends on how hot you want it in your fantasy world. Really no right answer that I know of, just what fits the dm’s style of play.

 

[Baron Opal II]

But, that's not normally how area of effects work - nomrally each target within the area takes full damage.

Or, have you been having a dragon breathe on the PCs, and divide the damage among them?

True, but PCs are small compared to dragons and squishy as well. Castles are often neither. I would consider that effects would be different given the context.