I've occasionally thought about designing a tabletop RPG with Absolutely No Special Cases. Instead of having stats (strength, intelligence, charisma, dexterity, what-have-you), skills (lockpicking, swords, whatever), abilities/powers/spells/features (flight, fireballs, bow attack), and so on, all of those mechanical things are combined into a single "elements" or "attributes" list. So if you want you can decide to not even have hit points.

I don't think this would work but it sounds neat.