AI systems reached superhuman performance in 2 player, zero-sum games (where one player wins, the other loses) such as Chess, Checkers, Go, and two-player poker. Now, an AI called Pluribus is capable of defeating elite poker players in 6 player, no-limit Texas Hold'em Poker, the most common game format. Poker elegantly captures the challenges of hidden information games. There are too many decision points to navigate individually, so, some actions are disregarded, and similar decisions are bucketed together in a simplification process called abstraction. AI systems that win in zero-sum games approximate the Nash equilibrium strategies and generate moves accordingly.

Don't simply "all in" if there's a bot at your Texas hold'em poker table, because Facebook and Carnegie Mellon University's new Pluribus AI system just beat five human pros at the same time -- including a couple of World Series of Poker Champs. AI models had already bettered human poker pros one-on-one, but Pluribus's success in a six-player game signals a huge leap in ability. Texas hold'em is one of the most popular poker variants that involves game theory, gambling, and strategy. To win the game, each play must assemble the best five cards from any combination of two "hole cards" dealt face down to each player and five community cards dealt face up. Players can choose to check, bet, call, raise, and fold. Researchers regard poker as a meaningful and complex experimental field where they can explore how AI interacts with gaming theory and imperfect information.