A friend wrote this on a message board about rules:
I was wondering about the shape of cone spells, and found this page: vertical height of area spells.
So what do you think ... does a cone spell expand outward in the same fashion on the vertical axis as on the horizontal (so a 15' color spray is 5' high adjacent to the caster, but 15' high in its most distant squares)? Or is it just a 5' high cone throughout the whole 15' horizontal area?
I commented:
Based on the diagrams in the rules, you have to assume that half the cone is above ground and the other half is below (like a tiny hut). So a 15 ft cone covers a semicircle with radius 7.5 ft at its furthest point. If you want to be kind, you could assume it reaches 10 ft up at its highest.
BUT ... If a character wanted to cast it on a foe 15 ft overhead, I'd allow it, of course.
So your view is that it's a 3 dimensional cone? The wording is that "it starts from any corner of your square and widens out as it goes." So I wasn't sure if it has any height.
Well, the term is "cone" -- not "triangle." :-)