Dark Sun: The Wayward Chronicles
This is the native tribe of Sheera Khan, a group of elves that run the sands north of the Tablelands. It is a harsh culture they live in, matriarchal and xenophobic, run by a single elf, called the Khan of Khans. Only those in line of descent from earlier Khans may make any attempt at claiming leadership, and it only passes through a show of strength: slaying the current Khan in a formalized duel, usually the challenger’s mother.
Adulthood is also earned within the Khan. Girl-children are gathered at their twentieth High Sun and sent alone into the desert after a purification ritual. They must see the outside world for themselves and bring back something of use to the tribe. Families are compensated in advance for the potential loss of a daughter. Boy-children do not undergo the rite of passage, as males are seen as inferior.
Births are highly controlled within the tribe, as numbers will otherwise become unsustainable among the sands. To this end males of the tribe are forced to eat a contraceptive herb, rendering them sterile temporarily. If an unauthorized pregnancy occurs, the male of the couple is slain to make room for the new addition.