Poker is a card game with elements of chance, but it also requires substantial skill and psychology. Players must make bluffing decisions to win bets from their opponents, but it is difficult to know how often their opponent is bluffing when they do not show their cards.

The game is played between two or more players sitting around a table. Each player places an ante or blind bet, and the dealer then deals each player a number of cards, one at a time, beginning with the player to their left. Depending on the variant of poker, some or all of the cards may be dealt face up or face down. During each betting interval, or round, the players can choose to call a bet by putting the same amount of chips into the pot as the player to their left; raise the bet; or drop (fold) their hand and leave the game, leaving any remaining chips in the pot.

Professional poker players use a range of skills, including observation and reading their opponents. They analyze the way that their opponents move their bodies and their hands, as well as the tone of their voice and the content of their speech. They can even use software that collects and analyses their opponent’s behavioral dossier, or ‘hand history’. It is not uncommon for a skilled player to be able to tell when an opponent is bluffing by the manner in which they bet and raise their bets.