There is a scene that sticks with me from childhood from the D&D cartoon series. Dungeon Master (the little bald dude) is teaching the principles of magic to the cowardly cavalier. The lesson is that summoning a spring of water to quench your thirst deprives another part of the world of water.
This seems an important moral about maintaining balance in a self-contained system. But of course, it has nothing to do with how magic actually works in the D&D role playing game. I’ve never read a version of the create water spell that mentions its contribution to desertification. But could magic in an RPG work more like this?