1. A style of game play in which as many players are allowed to join as the participants choose, and anyone can quit at any time. The term, most often used in the context of gambling, is borrowed from poker. The folk games three-ball and killer are usually played as open ring games, as is Kelly pool.
2. By extension, a multi-player game that anyone may initially join, but which has a fixed roster of competitors once it begins, is sometimes also called a ring game. Cutthroat is, by its nature, such a game. A famous regular ring game event of this sort is the Grady Mathews-hosted six-player, $3000-buy-in ring ten-ball competition at the annual Derby City Classic.
3. A nine-ballring game is played by more than two players and has special rules. Typically, the players choose a random method for setting the order of play, with the winner breaking. Safeties are not allowed and there are two or more money balls – usually the five and nine.