Master of Magic is an old PC game that I'm a bit fond of; it's got its share of flaws, but it's something that could be made into a playable world fairly well, particularly for a Dungeon Fantasy type game. It has a peculiar similarity to Magic the Gathering, though I'm not aware of any formal links. Like all 4x games it has a somewhat peculiar concept of time, with city growth being significant on the time scale of army motion, but this can be fairly easily papered over, and most people inclined to play this sort of world aren't going to sweat the economics anyway.