Poker is a card game whose twin elements of chance and skill are required to win. A good player can compensate for a certain degree of luck by making the right decisions at the right time and by using strategies based on probability, psychology, and game theory. Over time, the application of skill will eliminate the variance of chance and allow a player to achieve long-run expectation.

Each player must “buy in” with chips (representing money, for which the game is almost always played) equal to or higher than the amount of money placed into the pot by the players preceding him. This mandatory investment gives the player a share of the money in the pot and makes him eligible to make future bets.

Once all players have received their two cards, a round of betting begins. The first bets are called blinds and are placed into the pot by the players to the left of the dealer. After the blinds, players can choose to call or raise bets.

When a player’s hand is strong, it is advantageous to bet aggressively. This forces weaker hands to either call or fold, which increases the payout for a winning hand. It is also common for players to bluff at times in order to win the pot.

When a player is weak, it is usually best to check and wait for the flop or river. Some classic tells in poker include shallow breathing, sighing, nostril flaring, staring into the pot, watery eyes, and shaking hands.