So I've ben building a tabletop RPG for quite a few years, gone through all the mechanics, we have a timeline laid out for doing a TON of playtesting (individually, local friends, local game stores, maybe even online) as well as how we'll probably release it (rules are free, books are not, expansions to extend specific settings, skill arenas, etc.), and now I'm working on filling out some of the semantics.
We built it from the ground up, so I'm not too worried about mechanics. That was one of the main ideals, in fact - because we don't like the typical d20 setup, and we want it to be fairly unique, strategy-based, etc. Of course, since I've become more experienced and looked at other games, and it basically confirmed what we've learned on our own over the years and intervening iterations. (Happened sorta like convergent evolution, which I still kind of geek out over.)
One of the other main ideals is that, like GURPS or similar, you can play it using any setting, 'power source', or theme. And now I'm working on filling out 'example lists' to choose from. (Because, as we've found, some players are as stumped at 'Make something up!' as we are frustrated about 'These are your 3 flavors. Only 3.') So we've instead focused on a 'formulaic' approach, basically multiplying lists of stuff - x power source times y weapon equals z item, and using separate mechanics from semantics, sort of like Mutants and Masterminds.
Rant aside, my concern here is in getting 'inspiration' and themes from other games, (like D&D suppliments, Pathfinders, etc.) I don't want to copy too much. For 'uniqueness' purposes, but also for potential legal issues. At the same time, however, (a) these are known for being super inclusive, and I want to cover the 'traditional' themes as well as encouraging original themes.
If I'm overly concerned about 'copying' then traditional settings like Steampunk/Alchemy or Modern tech end up with some pretty identical lists. I am looking through lists to gather 'themes' I can use, not too worried about that. Where it gets dicey for me is when I like a specific metallurgical Alchemy component, for example, I can tweak and rename, but what if I want 10 from the same list? How many is too many?
And we know that at least some players will want to make a completely 'inspired' cough #unoriginal# character like a Jedi or a HP Wizard or a Power Ranger. * Shudder * I have no interest in releasing an extension for something like that, of course... But I wonder if even a tweaked version would be an issue. Though we did joke about releasing a My Little Pony setting.
Any thoughts, examples, feedback, or gems of wisdom you can offer on the subject?