pathfinder

I like to think my rules aren't sketchy, but the closest would be for character building my rules for uncommon and rare options are "tell me a story i can't say no to"

For uncommon options I'm pretty willing to take anything as long as it's not just an obvious power grab. For rare stuff i look more to see how much thought they've put into it and if it would negatively affect the rest of the party.

End result: I've had some pretty freak tables and others where everyone sticks to core ancestries.