Poker is a card game where players bet on the outcome of a hand using actions chosen on the basis of probability, psychology and game theory. With the exception of initial forced bets (‘antes’ or ‘blinds’), money placed into the pot is done so voluntarily by players who believe that their bet has positive expected value or who wish to bluff other players for various strategic reasons.

The game is popular in casinos and private games, but also in public events such as charity fundraisers and sporting matches. It is also a major component of many online gambling sites. The most important aspect of the game is establishing the player’s relative position, which depends on the number of other players at the table and the size of their initial bets. Once this has been determined, players must decide whether to call or raise the bets of their opponents.

Tournaments vary in size, but the smallest are often called locals or ‘weeklies’ and consist of groups of friends who get together to bring structure to friendly competitions. They are held in bars, card shops and community centers and are typically inexpensive to enter.

The game has been transformed in recent decades from an intuitive feel into a detached quantitative analysis, with professionals honing their skills by cranking out endless computer simulations and memorizing their solutions. As a result, a lot of the traditional advice for new players is either obsolete or misleading.