HORSE is a mixed‑game format rotating Hold’em, Omaha Hi‑Lo, Razz, Stud, and Stud Hi‑Lo.
Explanation. The name is an acronym from its constituent games: H‑O‑R‑S‑E. Players switch formats each orbit or set number of hands. It tests breadth: players must be skilled in multiple variants. HORSE gained popularity in high-stakes and tournament circles as a versatility challenge.