The Northlands had families that worked in similar industries. They intermarried to avoid socializing with the other tribes. The Salmon people, the Sailors, the Flameheads and the Wagon People are some of the 12 tribes. Family/tribe loyalties are very strong, and these divisions made it easier for the Empire to take over this area – the whole people were never united in anything.
Membership in a tribe is very important, but only in the Northlands (gameplay happens in the empire of the Southlands). When a tribe member comes into other regions in the Empire, they hold no status or reputation.
Only planet-born characters can be of one of the 12 Tribes and then only if they were born in the region.