I've always been a fan of the Chronicles of Narnia, and I was thinking about a game that borrows some concepts from that world.
So my question is how far am I legally allowed to take an idea that is based off of someone else's work? I'm assuming I couldn't have the word Narnia anywhere in the game, but can certain concepts be included in the game that are uniquely a part of that universe.
For example, in one of the books there is a place called "The Wood Between The Worlds." Would I be allowed to have a location titled that in my game that is based off that location in the book, or would that be an infringement?