We have that, it's called miasma
Miasma is a bit more involved then simply just being smelly smelly... Though the Material breaths can't produce Miasma anyhow.
It would be needed for Skunks and other creatures that do attack opponents through smelly projections that can be basically harmless otherwise.
And also that they're stupid
They also exist in real life. Though I am working more for the framework to make them possible then for them to be included in vanilla. Especially since it can be easily expanded to other areas that would be "Less silly" such as hurling poisonous barbs and poisonous spit that isn't a huge cone.
You don't want the game trying to simulate fluid jets. Trust me on this
Naw it is more that you want the game to recognise that for a Material Breath stream to recognise possible Force. So you could add that it has a certain force, it adds the material density for the liquid... then it does damage.
We definately don't need this to be handled in the Physics in all likelyness with a few exceptions.
Among all the other problems with this idea, lasers were invented post-1400
It was an example that basically even though we are saying "breath" that it doesn't involve breathing.
Yes, it is
I don't really know why you think the idea is all that stupid... I agree it is stupid for every creature to have (especially trolls) but it works for dedicated creatures.
Ignoring all that... Even if not included in Vanilla... that ability to ADD IT properly provides a proper framework for other attacks that are definately not stupid.
And then someone will want lakes of acid, and then pumps and channels of flowing acid, and then reactions between acid and certain types of stone, acid and booze, acid and water, acid and magma, acid and flesh, different types of acid, "here's this thing I heard about in chemistry class, why isn't it in the game yet"...
People already want it. So it doesn't really change anything.