Poker is a card game in which players bet against each other, placing chips or money into the pot. The player with the best hand wins the pot. The game can involve many betting rounds. The game requires a mix of skill, strategy and psychology, with the ability to read opponents and predict odds essential to success. In addition, a significant portion of the game is played through bluffing, and bluffing requires good understanding of probability and game theory.

To play the game, each player places an ante into the pot before being dealt five cards. Each player then has the option to call a bet or fold. When a player says “call” they place the same amount in the pot as the previous person who has raised the bet. If they don’t want to continue, they can say “I fold”.

When a player has a high-ranking hand, they can choose to raise their bet, hoping that opponents will call them. A high-ranked hand consists of any combination of cards that has a rank higher than the lowest. The highest ranking hand is the royal flush, which includes an ace, king, queen, jack and ten of the same suit.

Although poker has a substantial element of luck, it is a competitive skill game. In the long run, the best players will win. By studying the structure and rules of the game, von Neumann was able to determine optimal frequencies and ranges for both bluffing and calling, with the goal of winning as much money as possible.