'K, I'm not neccessarily starting, one (unless there are at least two people who are into it, and it would need to be a homebrew), but it's a question if that would even be ok to do?
I suppose it would be the longest game ever and everyone would need to be honest with their roles... but would that be even ok as an idea?
Also from what I've been told game mechanics are not copyrightable, so saying "class such and such can do this and this", "such spell has this effect" isn't breaking any rules, or laws pre se...