Athas

The desert world of Athas was once a lush and verdant planet, covered by a vast ocean and continents full of plant, animal, and humanoid life. Now, after centuries of being drained by arcane forces, the planet is little more than sandy wastelands, volcanic ranges, salt flats, and silt seas under a dying red sun. Survival is both paramount and difficult, as the dangers of the desert are many—heat, dehydration, beasts, other desperate people. In an area between the Ringing Mountains and the Sea of Silt, called the Tablelands, seven city-states cling to a semblance of civilization. Each is (or was until recently) ruled by a powerful sorcerer-regent. These arcane casters are quasi-immortal tyrants who are more feared than respected by those they rule. Outside the relative safety of the walls, all order collapses, and those who cannot fend for themselves are left to die or, more likely, be gruesomely killed. This is not a kind world; heroes are few and far between, and rule of might is law.   [some content is adapted directly from AD&D/4e, other content is original]