Big O Rules

Big O is a form of Omaha in which each player receives five hole cards. The object is to win the pot with the best hand at showdown, or by making a bet that no other player calls.

The game is played with a standard 52-card deck with no jokers and no wild cards. High hands are ranked according to the standard poker hand rankings.

Between two and eight players may take part. With five hole cards each, nine players would need 45 cards before the board and burn cards are dealt, which the deck cannot supply.

The name Big O is used for five-card Omaha and sometimes also for Six Card Omaha. In many cardrooms and mixed games, Big O refers in particular to the high-low version. The dealer or the venue shall announce whether the game is high only or high-low before play begins.

The button, blinds and order of action are the same as in Omaha and Texas Hold'em. The player to the left of the button posts the small blind and the next player to the left posts the big blind.

The dealer deals the cards one at a time, face down and clockwise, starting with the small blind, until each player has five hole cards.

Players shall keep their hole cards concealed from the other players until the showdown.

A card is burned before the flop, the turn and the river.

Big O is most often played pot-limit. Fixed-limit and other structures are possible; see betting structures. In fixed-limit play the bet size doubles on the turn and the river.

Each player's hand shall be made from exactly two of their five hole cards and exactly three of the five community cards. No other combination is permitted.

The three hole cards a player does not use, and the two community cards they do not use, have no effect on the value of the hand.

A player cannot make a flush unless at least three community cards are of the same suit, however many cards of that suit they hold. Likewise, a player holding three or more cards of one rank can use only two of them.

The pot is split equally between the best high hand and the best qualifying low hand.

To qualify for low, a hand must consist of five cards of different ranks, none higher than an eight. Aces count as low, and straights and flushes do not count against a low hand. The best possible low is 5-4-3-2-A.

Low hands are compared from the highest card down. For example, 7-5-4-3-2 beats 7-6-3-2-A.

A player may use different pairs of hole cards, and different community cards, for the high and the low. Each hand must still use exactly two hole cards and exactly three community cards.

If no player has a qualifying low, the best high hand wins the whole pot. Players who tie for high or for low share that half equally.

The order of showing and the other showdown procedures are the same as in Omaha. The last player to bet or raise on the river shows first; if the river was checked through, the first active player to the left of the button shows first.

The cards speak. A player who shows all five hole cards is entitled to the best high hand and, in the high-low game, the best low hand those cards can make, whatever the player declares.

An odd chip that cannot be split goes to the high hand in a high-low pot. Between tied players, it goes to the first tied player to the left of the button.