Official poker is a card game in which players make wagers with chips that represent their stake in the game. The player with the best hand wins the pot, which consists of all bets made by players in that round.
Before the cards are dealt each player must place a small blind bet or “ante” to cover his or her position. The player to the left of the dealer must either call the ante (or re-raise it) or fold. Only active players may participate in the betting during each round.
After the flop is dealt, there is another round of betting. Players may check, bet, call the bet of another player, or raise (or re-raise). Once all players have either called the highest bet of a player or folded, the game ends and the pot is awarded to the winner of that hand.
In addition to the mandatory blinds, some players may choose to post straddle bets to encourage action in the game. These bets, which are placed in the same way as the big and small blinds, are worth two times the amount of the button. However, they have a negative expected value from a game theoretical point of view.
A key distinction between regular poker and tournament play is that in a tournament the percentage of players who receive any money can be much lower than in a cash game. A rough rule of thumb is that close to 10% of the players will be paid in a tournament, but this can vary significantly depending on the structure of the event and other factors.