Poker is a card game played with a standard pack of 52 cards (although some variant games use multiple packs or add jokers). The cards are ranked from high to low (Ace, King, Queen, Jack) and have four suits (spades, hearts, diamonds and clubs). All poker hands must contain five cards. The highest-ranking hand wins. Some poker games include wild cards, which can take the rank and suit of any other card to form a winning hand.

The game of Poker requires considerable skill and understanding of probability and psychology. While the outcome of a single hand is mostly determined by chance, over time players can significantly improve their expected value through decisions made on the basis of probability theory, strategy and psychology.

When players place money into the pot voluntarily, they are known as raising, or increasing the bet. This can be done by simply matching the amount raised by another player, or by raising it further. A player may also choose to fold, forfeiting the round.

A player must act in turn, which starts with the first active player to their left. When the player acting in turn has a better hand than any other, they must place their chips into the pot to show it, and all other players must match or raise his bet in order to stay in the pot. If no one raises, the original player must check if he wants to play the next round or fold if not.