Poker is a card game whose rules and variants vary widely, but all involve betting and the placement of chips (representing money) into the pot. The object is to win the pot by having the highest ranking poker hand at the end of a betting round. A player may also try to bluff other players in order to win the pot. The game is based on probability, psychology, and game theory.
In most games, a complete hand of five cards is dealt to each player. There are one or more betting rounds during a deal, with raising and re-raising allowed.
A player must make a forced bet, called an ante or blind bet, before he can act in a betting round. He may then raise his bet, or fold if he does not want to continue. If he raises his bet, he must place chips into the pot equal to the amount raised by the player before him. This is called opening the round.
If he does not wish to raise his bet, the player can check his option by tapping the table with a fist, knuckles, an open hand or the index finger(s). He must say “Check,” and then place his own chips into the pot if necessary to keep the action going. If no one checks, the betting round ends and a new hand is dealt.