THE BASIC RULES:
When playing poker you use a standard 52 card deck, you set-up hands of five cards according to predetermined rules which vary according to which variant of poker is being played. These hands are compared using a hand ranking system that is standard across all variants of poker, the player with the highest-ranking hand winning that particular deal in most variants of poker. In some variants, the lowest-ranking hand can win or tie.
The winning hands break down as follows:
An ace-high straight flush such as 10♦ J♦ Q♦ K♦ A♦ is known as a royal flush, and is the highest ranking standard poker hand.
A straight flush is a hand that contains five cards in sequence, all of the same suit, such as Q♣ J♣ 10♣ 9♣ 8♣. Two such hands are compared by their card that is ranked highest. Because suits have no relative value, two otherwise identical straight flushes tie (so 10♣ 9♣ 8♣ 7♣ 6♣ ties with 10♥ 9♥ 8♥ 7♥ 6♥). Aces can play low in straights and straight flushes: 5♦ 4♦ 3♦ 2♦ A♦ is a 5-high straight flush, also known as a "steel wheel".
FOUR OF A KIND
Four of a kind, also known as quads, is a poker hand such as 9♣ 9♠ 9♦ 9♥ J♥, which contains four cards of one rank, and an unmatched card of another rank. Quads with higher ranking cards defeat lower ranking ones. In community-card games (such as Texas Hold 'em) or games with wildcards it is possible for two or more players to obtain the same quad; in this instance, the unmatched card acts as a kicker, so 7♣ 7♠ 7♦ 7♥ J♥ defeats 7♣ 7♠ 7♦ 7♥ 10♣. If two hands have the same kicker, they tie and the pot is split.
A full house, also known as a full boat, is a hand such as 3♣ 3♠ 3♦ 6♣ 6♥, which contains three matching cards of one rank, and two matching cards of another rank. Between two full houses, the one with the higher ranking three cards wins, so 7♠ 7♥ 7♦ 4♠ 4♣ defeats 6♠ 6♥ 6♦ A♠ A♣. If two hands have the same three cards (possible in wild card and community card games), the hand with the higher pair wins, so 5♥ 5♦ 5♠ Q♥ Q♣ defeats 5♣ 5♦ 5♠ J♠ J♦. Full houses are described as "Three full of Pair" or occasionally "Three over Pair"; Q♣ Q♦ Q♠ 9♥ 9♣ could be described as "Queens over nines", "Queens full of nines", or simply "Queens full".
A flush is a poker hand such as Q♣ 10♣ 7♣ 6♣ 4♣, where all five cards are of the same suit. If the hand also has all the cards in sequential order, it would be a straight flush. Two flushes are compared as if they were high card hands; the highest ranking card of each is compared to determine the winner. If both hands have the same highest card, then the second-highest ranking card is compared, and so on until a difference is found. If the two flushes contain the same five ranks of cards, they are tied and split the pot, that is, suits are not used to rank them.
Flushes are described by their highest card, as in "queen-high flush" to describe Q♦ 9♦ 7♦ 4♦ 3♦. If the rank of the second card is important, it can also be included: K♠ 10♠ 5♠ 3♠ 2♠ is a "king-ten-high flush" or just a "king-ten flush", while K♥ Q♥ 9♥ 5♥ 4♥ is a "king-queen-high flush". However an alternate method of describing a flush can be utilized specifically in community card games, like Texas Hold 'em, where the highest ranking card in the flush sometimes will be a community card, and as such becomes irrelevant for its rank. In such situations, a person's flush might be described as being as high as his hold cards. For example, consider that the community cards show A♣ 10♣ 6♣ 2♣, and Player A has hold cards of Q♣ J♦ while Player B has hold cards of K♣ 10♠. The A♣ is playable by both and becomes irrelevant in determining which player holds the higher flush so Player A's hand can be described as a queen high flush while Player B holds a king high flush. In this case, both players have a flush of the same suit, and because it is a community card game they have equal rights to the high ace, which consequently counteracts the ace being a meaningful high card any longer. Because in games like five card draw, two players cannot have an ace high flush of the same suit and the former method is always used.
A straight is a poker hand such as Q♣ J♠ 10♠ 9♥ 8♥, which contains five cards of sequential rank. If the cards were also all of the same suit, the hand would be a straight flush. Two straights are ranked by comparing the highest card of each. Two straights with the same high card are of equal value, suits are not used to separate them.
Straights are described by their highest card, as in "ten-high straight" or "straight to the ten" for 10♣ 9♦ 8♥ 7♣ 6♠.
A hand such as A♣ K♣ Q♦ J♠ 10♠ is an ace-high straight (also known as Broadway), and ranks above a king-high straight such as K♥ Q♠ J♥ 10♥ 9♣. The ace may also be played as a low card in a five-high straight such as 5♠ 4♦ 3♦ 2♠ A♥, which is colloquially known as a wheel. The ace may not "wrap around", or play both high and low: 3♣ 2♦ A♥ K♠ Q♣ is not a straight, just an ace-high high card.
THREE OF A KIND
Three of a kind, also called trips or a set, is a poker hand such as 2♦ 2♠ 2♣ K♠ 6♥, which contains three cards of the same rank, plus two unmatched cards. In Texas hold 'em and other flop games, three of a kind is called a "set" only when it is composed of a pocket pair and one card of matching rank on the board (as opposed to two matching cards on the board and a third in the player's hand).
Higher-valued three of a kind defeat lower-valued three of a kind, so Q♠ Q♥ Q♦ 7♠ 4♣ defeats J♠ J♣ J♦ A♦ K♣. If two hands contain three of a kind of the same value, which is possible in games with wild cards or community cards, the kickers are compared to break the tie, so 4♦ 4♣ 4♠ 9♦ 2♣ defeats 4♦ 4♣ 4♠ 8♣ 7♦.
A poker hand such as J♥ J♣ 4♣ 4♠ 9♥, which contains two cards of the same rank, plus two cards of another rank (that match each other but not the first pair), plus one unmatched card, is called two pair. To rank two hands both containing two pair, the higher ranking pair of each is first compared, and the higher pair wins (so 10♠ 10♣ 8♥ 8♣ 4♠ defeats 8♥ 8♣ 4♠ 4♣ 10♠). If both hands have the same top pair, then the second pair of each is compared, such that 10♠ 10♣ 8♥ 8♣ 4♠ defeats 10♠ 10♣ 4♠ 4♥ 8♥. If both hands have the same two pairs, the kicker determines the winner, so 10♠ 10♣ 8♥ 8♣ A♦ beats 10♠ 10♣ 8♥ 8♣ 4♠. Finally, if both hands have the same two pair and same kicker, the pot is split.
Two pair are described by the higher pair first, followed by the lower pair if necessary; K♣ K♦ 9♠ 9♥ 5♥ is described as "Kings over nines", "Kings and nines", or simply "Kings up" if the nines are not important.
One pair is a poker hand such as 4♥ 4♠ K♠ 10♦ 5♠, which contains two cards of the same rank, plus three other unmatched cards. Higher ranking pairs defeat lower ranking pairs; if two hands have the same pair, the non-paired cards (the kickers) are compared in descending order to determine the winner.