Some time ago, I wrote about the possible use of inconstant geography in gaming. I don't want to rehash that here, but it has been rumbling around in my head since then, and I recently added a new twist that I think solves some of the issues in the right sort of setting. Imagine a world where the path between two locations is inconstant due primarily to story concerns. This is likely a world in which narrative concerns are part of the fabric of reality (such as some depictions of Fairy, some virtual worlds, some worlds that gain their shape from the imagination, etc.).
What if, in such a world, following a map (that was created through a proper process) would always work? Fixing the path down on paper (or whatever) fixes the path itself.
I thought this was sort of cool. Given the right setting, you could have the best of both inconstant and fixed geography.
A related thought:
It is a staple of fantasy that fairies always tell the truth, but often mislead.
The common manner of dealing with this is to assume that, for some reason, fairies are bound not to lie.
What if, instead, the world bent in order to make the words of fairies be true?