D&D 5E Can a fireball melt ice?

[pemerton]

Like the thread topic says.

Here is the text of the fireball spell that seems relevant (SRD, pp 142-43):

A bright streak flashes from your pointing finger to a point you choose within range and then blossoms with a low roar into an explosion of flame. Each creature . . . takes . . . fire damage . . . The fire . . . ignites flammable objects in the area that aren’t being worn or carried.​

If the text describing the ignition of flammable objects that are neither worn nor carried is exhaustive of the effect of the spell upon things other than creatures, that would seem to imply that the spell can't melt ice. (Which is very obviously not a flammable material.)

 

[ccs]

You're the DM, how do you want it to work?
If you're not the DM, then how does the DM want it to work?

 

[jgsugden]

Up to the DM, but I'd have the fireball shatter the ice and melt the surface layer.... but thick ice would remain mostly frozen.

 

[Savage Wombat]

How much damage did you roll? How thick is the ice?

 

[Umbran]

If you want a real physics answer - heat does not transfer instantaneously. It takes time for heat to flow from one thing to another. A flash like a fireball is not around long, and so probably doesn't deposit much heat into ice, so the ice (which takes a *lot* of heat to melt, relative to most materials around) probably won't melt much. The hot gases that make up the flame will simply disperse, and their heat will go into the air, instead.

 

[ZzarkLinux]

Voted yes, but it really depends on setting.
- In Forgotten Realms, yes, because that setting allows water to ignite into steam
- In Athas, no, because the desert is dry and there is no ice to ignite
- In popular childrens settings, yes, and it works underwater too

Global things like fire and ice are setting dependent. Not house-rule dependent.

 

[bid]

Next time you sear some steak, put an ice cube in the frying pan. Compare to how long your hand could stay in there.

Ice takes way more than 6 seconds to melt significantly.

Misquoting wikipedia for all I care:
- 333 J/g to melt
- 418 J/g to heat
- 2257 J/g to boil
You'd have to vaporize or let the melted water flow away to reach deeper into the ice block.

OTOH, a continuous jet of firebolt would need 30 seconds (1d10 vs 8d6) to match fireball. But if it only has to melt and let the water flow, it would work faster (9 times the energy means 14d6 to vaporize ice = 1d10 to melt it). If the firebolt bring the flowing water to scalding temperature, fireball could vaporize the same volume.

So no, very little would melt.

 

[Hriston]

How much ice are we talking here?

 

[pemerton]

How much ice are we talking here?

I didn't have a particular quantity in mind.

Let's say an ice pendant worn by a frost giant chieftain. And the thin sheet of ice serving as "glass" in the chieftain's house.

 

[Dausuul]

In principle: Yes. A fireball can melt ice. That said, it can't melt much ice, for the reasons Bid laid out. It could certainly melt holes in a thin sheet, but probably not the pendant (even if it weren't being worn/carried).