The card game of poker has many variations, most of them created in the United States in the mid-1900s. The standard order of play applies to most of these games, but to fully specify a poker game requires details about which hand values are used, the number of betting rounds, and exactly what cards are dealt and what other actions are taken between rounds.

Popular poker variants

The three most popular poker variants are spread in casinos and poker rooms worldwide and can be divided into the following groups:

• Draw poker: Games in which players are dealt a complete hand, hidden, and then improve it by replacing cards. The most common of these is Five-card draw.
• Stud poker: Games in which each player receives a combination of face-up cards and face-down cards in multiple betting rounds. The most common of these are Seven-card stud and Five-card stud.
• Community card poker: Games in which each player's incomplete hidden hand is combined with shared face-up cards. The most common of these are Texas hold 'em and Omaha hold 'em.

Here are more common rule variations:

1. High-low split: the highest and lowest hands split the pot. Generally there is a qualifier for the low hand. For example, the low hand must have 5 cards with ranks of 8 or less. In most high-low games the usual rank of poker hands is observed, so that an unsuited broken straight (7-5-4-3-2) wins low (see Morehead, Official Rules of Card Games). In a variant, based on Lowball, where only the low hand wins, a straight or a flush does not matter for a low hand. So the best low hand is 5-4-3-2-A, suited or not.
2. Lowball: The lowest hand wins the pot. There are different rules about whether or not aces count as low, and the effects of straights and flushes. The most common variants are Razz and 2-7 Triple Draw
3. Players can pass cards to each other. An example of this would be Anaconda.
4. 'Kill game'. When a fixed limit game is played and a player wins two pots in a row, the stakes are doubled. In some split-pot games (e.g., Omaha), a player winning both halves of the pot may also cause a kill. In some variants of Lowball, a player may choose to kill by placing a double bet after seeing his first two cards.
5. Wild cards are added. This can range from simply making deuces wild to the wild 7-stud variant of baseball.
6. A twist round in which players can buy another card from the deck. If a player does not like the purchased card, the player can purchase another one by adding money to the pot. This is sometimes called a "Tittle."
7. A stripped deck may be used. Poker was first played with only 20 cards. In the spirit of poker history, players will sometimes only play with a stripped deck. A popular poker game in Spain is played with cards 8-A. It is played similar to hold'em, except that one card is dealt at a time and a player must use both hole cards.
8. Each player is dealt a certain number of cards. Then there is usually a number of community cards that all players can use. When forming a poker hand a player may use cards from his hand and the "community cards". Examples of community card poker include Texas hold 'em and Omaha hold 'em.