Poker is a card game in which players place chips into a pot (representing money) to compete for the best hand. A player wins the pot when other players fold or when they have the best remaining hand. While the result of any individual hand may be influenced by luck, in the long run a player’s choices made on the basis of probability, psychology and game theory determine how much they win or lose.
Each player begins with two cards that are face down (hidden from other players) and then enters a betting phase, called the pre-flop. Each player has the option to fold, call, or raise a bet placed by another player before him. Bet sizes are usually based on the amount of the bet before it or the size of the pot.
After the pre-flop betting phase, 3 more cards are dealt face up at the center of the table (revealed to all players) called the flop. Each player can use these community cards to make a 5-card hand.
Each player can fold, check (not place any money into the pot), call, or raise a bet placed on him by another player before him. Each player is working with incomplete information, and every action — including the way a player calls, checks, or raises — gives away bits of information to opponents about his strength or weakness. Moreover, the way that a player acts tells his opponents when he is bluffing and how big of a bet he is willing to make if he has a strong hand.