The obligatory copyright stuff

With any project with multiple contributors, it's best to get some clarity on the copyright status of the contributions right from the start, especially if we have hopes of this becoming popular at some point...

Since it's the clearest and safest to explicitly assign all the copyrights to a single legal person, and it would be a bit of a hassle at this point to set up a separate legal entity that one could assign them to, I'm guessing that it would be the easiest if they were assigned to me? So that people wouldn't feel threatened about how their work might be used, the assignment would be on the condition that the work be licensed under an appropriate free license. (As explained e.g. here.)

The GPL is a nice license for code, but not necessarily for fiction - if someone wanted to write a novel based on the events of the game, for example, applying the GPL to that would get a bit weird. On the other hand, something like CreativeCommons-Attribution-ShareAlike is good for fiction, but not so much for code.

So maybe combine the two. I asked about this on my Facebook and Google Plus feeds, and the comments in those places are somewhat split between dual-licensing the whole project with both GPL and CC-BY-SA, or licensing the code with GPL and the art and writing with CC-BY-SA. I don't really know which option would be better, myself, or whether it really even matters. Thoughts?