The tribes are a nomadic group of people who live on the plains stretching from the where the Sierra Midgradias butt up against the pioneering towns of the Lobaskan Territories far to the east to the Sierra Endgradias. The tribes value horses above all else, and they migrate to prime hunting locations according to the seasons, following the massive herdsbeasts and, when food is sparse, raiding the villages of the pioneers, the Those That Stayed.

The members of the tribes are reared from birth in the role they will fulfill. Any role may be fulfilled by either gender, except featherkeepers, who are always women. Horsemen are often men, though women have ridden with them before, and it is not unprecidented. Tanners only need know tanning. Horsemen only need know war and horsemanship. Featherkeepers need only know the lore of their craft. The children know they have a role to keep the tribe operating properly, and as such, they are discouraged from asking around or watching the duties of others. It is a difficult life if one is not given the role for which he would be ideally suited.

For this reason, there are, occasionally, people who choose to leave the tribes and join the Those That Stayed. They may leave the tribes at any time they desire, but they may not return to live with them again. To ensure that one does not leave one tribe and join another, each tribe wears feathered earrings, which have been dyed using secret herbs, known only by the featherkeepers. Should a featherkeeper renounce her tribe, she must swear an oath to never again featherkeep. Should she be discovered doing so, the other exiles are bound by honor to kill her, lest one of the Those That Stayed use an opportunity like that to destroy the tribes.

The exiles still wear the feathered earrings of the tribes, but they may not at any time dye them again, in order to mark them as tribeless. If any choose to stop wearing their earrings, they are to be treated as a Those That Stayed, and they are fair game when the tribes raid the towns. Any found wearing the earrings of an exile are still considered blood, and they must not be harmed. The Those That Stayed consider the earrings to be marks of a savage, and they would not wear them. If any did, the exiles would be bound by honor to kill them, lest they find an opportunity to destroy the tribes.

The tribes have a rich oral history, and their religion is a largely shamanistic one, wrought with nature deities and scraggly elders who are obeyed lest some vestige of a centuries-old nature spirit invoke its wrath in the direction of the tribes.

There is one chief of every tribe, who is raised from childhood to be the chief. He chooses where to move, when to move, and how to move. He makes certain that no one wants for anything and the ways of the tribe are upheld and enforced. In these respects, he is more like quartermaster and police of the tribe. All decisions beyond those of where and when and how to move or to mete out justice for petty crimes are handled by the elders.

The Time of Trading is a great gathering for the tribes, wherein they meet and trade their wares and gossip and news. The Time of Trading is a massive, expansive, festival-like time, and it is the only time the exiles are welcomed back to the tribes for a time, to exchange news and gossip from the Those That Stayed for news of their families. The exiles also bring goods and items that the tribes cannot procure in any other way - new seeds, town-crafted goods, paper, fresh lines of livestock, etc.

Perhaps the most unique trait of the tribes is their near worship of the horse. The horsemen use their horses in every possible manner, and the horses are well-loved by the tribes. Tribes keep whole herds of unbridled, unsaddled horses to run free until they are needed for military maneuvers. Upon becoming a horseman, the youths must approach the herd, and the first to let the youth ride willingly becomes their horse until one of them dies. At this time, the youth is given a silver whistle, which have been passed down through the tribes since time immemorial. These whistles give the horsemen the ability to control horses, even those they had never met before. The whistles of a tribesman warcharge can be herd far across the plains, and its echoes stir up the enemy horses into a wild frenzy until they will not obey any master but the whistles. Skilled horsemen can control two or three groups of horses, though most can only drive one small herd or merely one horse.

The whistles work for none but the horsemen. They will elicit not even a sound for any but the one to which it was given until his death. For this reason, it is often speculated by the Those That Stayed that the whistles were given to the tribes long ago by the cult of the Hand of Fate.

The tribes neither support nor deny this allegation.