How can people be voting multiplayer? Either you have no friends or you're scared of competition.
Some of the best gaming moments in my life have been multiplayer, Barbarian, Renegade, Spy vs Spy, Streets of Rage II, Laser Squad, Powerstone, Streetfighter II, MvC 2, KoF, Tekken II, Gain Ground, Bomberman, Secret of Mana, Mario Kart, Gauntlet, Lord of the Rings, Command and Conquer, Action Quake, Diablo, CoD4...
I take that back, even if you are scared of competition then you can play plenty of stuff Co-op.
I went with magic. In a fantasy setting you can replace it with skills/special attacks and it would make most fantasy world based games try something different.