This is an idea I've had kicking around in my head. I'd use a heavily-modified retroclone.
1. All characters would be elves (fighter/mages of some kind). They would be the rulers of the world.
2. They would be just better than other races. Period. One level one elf could easily kill a group of five human soldiers.
3. They can wear armor, use weapons, etc. They also use magic.
4. Magic may be limited to stuff like leaping, healing, some kind of roar that demoralizes and deafens, etc. Not sure if I want stuff like lightning or not.
5. Anger and hate fuel magic. If you're nice and mellow, magic won't work, or at least it will be very diminished. Therefor, the most evil elves are also the ones running everything.
6. There is a rebellion, of course. It will have some elves in it. Maybe they use technology to combat elven magic.