In the real world, fiction can change the world - give people insights and create feelings they wouldn't otherwise have.
The Alan Wake games take it totally literally, running with the premise of being able to make stories real - and giving that power to a crime and horror writer who has to take a stand against horror turning real.
Alan Wake 2 got as far as a pitch, with some interesting monsters (hunched figures jumping on and over cars, and especially the guy turning into a flock of ravens, borrowed for the scaled-down sequel American Nightmare) and used making fiction real as a puzzle and a weapon. Set up the scene of an accident, cause the accident to happen. The bit at the end feels like kind of a stretch, though.
Set some parameters (like defining a Weird Level in rules terms?) and it could be an interesting power, particularly when two creators start using it against each other...