Originally Posted by endolex
I agree completely. Surfaces should be reigned in aka you can only set stuff on fire that can actually burn, you can only create a frozen slippery surface when it's wet, etc., and they all should allow for saving throws.

Even though that's still a departure from core 5e rules, I would still rather your suggestion than all the random effects and the ability to use cantrips/repeatable abilities to create surfaces.