I have been considering the idea that it might be possible to simply use categories to describe a game world, which is a crazy idea but perhaps worth trying to make consistent.
So what better way than to make an entire campaign setting around that and start breaking it?
The idea here is that the gods embody philosophical concepts and when destroyed, the concepts themselves are destroyed... along with whatever they originally operated.
If you destroy the god of lightning, not only will lightning storms become just storms, the concept of lightning itself vanishes from the world. As the players are going to be divine assassins in this sort of game, working out the ramifications for the removal of the equivalent of logical axioms will coincidentally also help improve the consistency.
The gods are, unfortunately, rather weak, unprepared and "easily" destroyed with planning and high level power. Which leads to a Fragile World setting where higher level characters out to make a name for themselves can, with alot of work, put down a god and change the world. Others might wish to stop them but that's just something they'll have to deal with until the god of Opposition is killed... (after which, goodness knows how that's going to work; perhaps the more abstract concepts can be ignored)
A god can be found for most concepts, but obviously a list is going to have been drawn up first.
SpoilerThe obvious ones are Life, Death and Existence. Kill Death and nothing can die, including the gods. Kill Life and everything dies immediately (including all the gods and thus the entire campaign world). Killing Existence leads to the end of the world. All lead to something rather boring.
Either way, destroying these major concepts should be immensely difficult if not outright impossible. Ending them also ends the campaign and requires a setting reset and so should be final targets.
The god of Speed/Movement would also be a rather... bad thing to off, as would the god of Shapes.
Other gods could be nested inside each other. The overall god of Earth would contain the god of Mountains and that would contain the god of Stone.
So, workable? Or about to go off the deep end very very soon?
How do you resolve a destroyed concept with the existence of history, at least until History is 6ft under? (eg. people used to get hit by lightning... which means what exactly?)