(Wasn't sure where to post this, so please move it if it's in the wrong place) I wanna set either a novel or a collection of short stories in a post-apocalyptic universe (I don't think that's ever been done before!...) but as a fan and long-time player of the Fallout games I'm worried about it turning into fan fiction, which I want to avoid. I'm not too familiar with the rules and boundaries of fan fiction, which is why I'm turning to you guys to help me out In short, I'm not gonna use any of the cities that have been used so far by the Fallout franchise. I'm not gonna use any of their factions, their characters or any of their lore, although due to the size of the Fallout universe, I think it's almost impossible to avoid similarities with at least some of it (sure, I won't call the criminal gang 'Raiders' but being a criminal gang, they will definitely share some traits). What I want to use from the Fallout universe are the vaults in particular, and the look and feel of the world in general - although I'll probably go for something other than a 1950's look. But I think it's hard to come up with a completely unique look and design of a post-apocalyptic wasteland or cities - one that quite a few post-apocalyptic games and shows share to some degree. So, how do I keep this from turning into fan fiction? Are there any rules to follow, any boundaries I should be aware of? Any help appreciated!