From publisher blurb:
Out of the swirling, bone-dry sands of Athas come hordes of raiders. They overrun caravans, strip them bare then vanish into the untracked wastes once more. Who are these ghosts of the desert? Where do they live? How do they survive far from the high walls of the city-states? Slave Tribes answers these and many more questions about the ex-slaves who escape into the desert.
The Dark Sun game world is now open to campaign in realms beyond the reach of sorcerer-kings. The most prominent and successful slave tribes of the Tyr region are presented in great detail in this accessory. Slave Tribes enables the DM to create entirely new tribes to roam the Dark Sun campaign. It also shows players how to form their own tribes when their characters escape the clutches of the sorcerer-kings. The deadly world of Athas shows no mercy to those who are unprepared for its dangers!