Learn to Play HORSE with the Professor's Guide. advanced game, as players must be familiar with the rules of all 5 poker variants used in this mixed game. H.O.R.S.E. is a multi-game form of poker commonly played at the high-stakes tables of casinos and in tournaments. It is most often played in a limit format, but. H.O.R.S.E Poker Rules - This article explains how HORSE poker is played and includes rules and strategy for each game in H.O.R.S.E. mix poker.