The Caste is the fundamental unit of social organisation in the Gorean setting. Each free person belongs to a Caste that defines occupation, obligations, dress and often bearing. Castes are ranked in the novels as High Castes and Low Castes, with distinct duties and privileges. Membership is generally understood as hereditary within the fiction, though the novels admit some movement between Castes under specific circumstances.

The Caste system is a central organising device of the Gorean setting and provides much of its distinctive vocabulary.

In community practice, references to Caste are sometimes literary, sometimes structural to a household's roleplay, and rarely applied literally to modern social organisation.