Poker (the wagering hand-comparison family)

Poker is a family of comparing card games in which players wager over which hand is best according to that game's rules. It is played worldwide with regional rule variations. The earliest known form was a 20-card game played in early-19th-century New Orleans; the modern 52-card form developed in mid-19th-century America.

Warnings: Poker is overwhelmingly played for stakes. This entry describes the rules and lineage of the family as a historical and game-design reference; the pack does not provide gambling advice or wagering strategy. Specific variants are described in their own entries.

In most poker games, the first round of betting begins with one or more players making a forced bet — the blind in modern community-card games, the ante in older draw and stud games. The action then proceeds clockwise. On each player's turn they must either match (call) the maximum previous bet, raise (increase) it, or fold (forfeit the hand and any bets so far). The betting round ends when all remaining players have either called the most recent bet or folded. If only one player has not folded, they collect the pot without showing their cards. If two or more remain after the final betting round, a showdown occurs: the hands are revealed and the highest-ranking hand wins the pot.

The standard hand ranking, from lowest to highest, is: high card, one pair, two pair, three of a kind, straight (five sequential ranks of mixed suits), flush (five cards of the same suit), full house (three of one rank with two of another), four of a kind, straight flush (five sequential ranks all in one suit), and royal flush (A-K-Q-J-10 in one suit). Some games invert this ranking (lowball) and others use both — the high hand and the low hand each win half the pot (high-low split games).

The poker family branches into three structural categories. Draw poker games (Five-Card Draw is the canonical form) deal each player a hand of cards, all hidden, with one or more rounds of betting and a chance to discard and replace some cards. Stud poker games (Five-Card Stud, Seven-Card Stud) deal each player a sequence of cards mixed face-up and face-down, with a betting round after most card deals; no cards are exchanged. Community card games (Texas Hold 'em, Omaha) deal each player a small number of hidden hole cards and place a set of cards face-up in the middle to be shared by all players in forming hands.