The World Series of Poker (WSOP) is a series of poker tournaments held annually in Paradise, Nevada and, since 2004, sponsored by Caesars Entertainment. It dates its origins to 1970, when Benny Binion invited seven of the best-known poker players to the Horseshoe Casino for a single tournament, with a set start and stop time, and a winner determined by a secret ballot of the seven players.

A poker tournament is a tournament where players compete by playing poker. It can feature as few as two players playing on a single table, and as many as tens of thousands of players playing on thousands of tables. The winner of the tournament is usually the person who wins every poker chip in the game and the others are awarded places based on the time of their elimination. To facilitate this, in most tournaments, blinds rise over the duration of the tournament. Unlike in a ring game, a player's chips in a tournament cannot be cashed out for money and serve only to determine the player's placing.