Omaha deals four hole cards instead of two, and the rule that comes with them is short: your final hand is exactly two of your hole cards and exactly three of the five board cards. Not one and four. Not three and two. Not zero and five. Almost every misread hand comes from the Hold'em habit of using whatever cards make the best five.
What the rule does to the count
In Hold'em you choose the best five cards from seven, which is C(7,5) = 21 possible hands, and any mix of hole and board cards is allowed. In Omaha you pick two from four, which is 6 ways, and three from five, which is 10 ways. That is 6 × 10 = 60 five-card hands to consider at the river. In 5-Card Omaha the same rule applies to a five-card hand: 10 pairs × 10 board triples = 100.
More hands means more draws and bigger hands. The restriction means you hold cards you are not allowed to use, and they are often the ones that catch your eye.
Dealing a few hundred hands makes the rule automatic. Omaha Poker has PLO, Omaha Hi-Lo and 5-Card Omaha tables to play offline, and its Help & Rules covers the two-cards rule.
Five hands that look made and are not
Each of these reads one way by Hold'em habit and another under the two-and-three rule.
| Your four cards | Board | Looks like | Actually |
|---|---|---|---|
| A♥ Q♠ Q♦ 7♣ | K♥ 9♥ 6♥ 3♥ 2♣ | Nut flush | Pair of queens |
| A♠ K♠ 8♠ 4♠ | Q♠ 9♠ 6♦ 3♣ 2♥ | Ace-high flush | Ace high |
| A♠ A♦ K♥ K♣ | 5♣ 6♦ 7♥ 8♠ 9♣ | Straight on the board | Pair of aces |
| A♠ K♦ Q♣ J♥ | T♠ 7♦ 4♣ 2♥ 2♠ | Ace-high straight | Pair of twos |
| 7♠ K♦ J♣ 4♥ | Q♥ Q♠ Q♣ 7♦ 3♥ | Queens full of sevens | Three queens |
One card of the suit is not enough. In the first hand the board has four hearts and you hold the ace. In Omaha you can use only three of the board's hearts, so you need two hearts of your own, and you have one. The best you can make is Q-Q with K-9-6 from the board.
Four of the suit is not a flush either. The second hand is the mirror image. Six spades in sight, but two from your hand and two from the board make only four. With no third spade on the board, nobody at the table can have a flush. Holding four of one suit is also a weak start: of the 13 spades, four are in your hand, which leaves 9 that could reach the board. If you held two, there would be 11.
You cannot play the board. In Hold'em a straight on the board belongs to everyone. In Omaha nobody may use five board cards. With A-A-K-K the best you can do is A-A with 9-8-7. A straight is still possible, but only for a player whose two hole cards fit it: T-J with 7-8-9 makes a jack-high straight, and 4-3 with 5-6-7 makes a seven-high one. Either beats your aces.
One card to a straight does nothing. In the fourth hand the board has a single ten. A-K-Q-J needs three cards from the board for a broadway straight, so it needs T and two more of A, K, Q or J, and the board has none of them. Your best hand is A-K with 2-2-T: a pair of twos.
One card does not fill a full house. In the fifth hand the board has three queens and you hold a seven. Once you use Q-Q-Q from the board, the other two cards must both come from your hand, so you need a pair in hand for a full house. Your best is K-J with Q-Q-Q.
The fix for all five is the same habit: never count a hand from your four cards and the board as a pile. Pick two of yours, pick three of the board, and only then name the hand.
Reading the board first
Because three board cards are always used, the board sets the ceiling on what anyone can hold. That gives three quick checks, in this order:
- Is the board paired? If not, no full house or four of a kind is possible. On a random five-card board a pair or better turns up about 49.3% of the time.
- Are three or more board cards of one suit? If not, no flush is possible, however many of the suit you hold. A random five-card board has three or more of one suit about 37.1% of the time, so on roughly five boards in eight nobody can have a flush.
- Do three board cards fit inside a five-rank window? If not, no straight is possible. A board of K-9-6-3-2 allows exactly one (a 5 and a 4 in hand with 6-3-2); a board of K-J-7-3-2 allows none, because no three of its cards fit inside five ranks.
The same checks tell you when your own hand is the best possible: on an unpaired board with no three of a suit, the top straight is the nuts.
The live hand insight in Omaha Poker groups your outs by what they make, a quick check on a hand that looks strong.
Starting hands built around the rule
Since only two of your cards play, the four should work together in pairs. A-A-A-K looks strong and is not: only two aces can ever play, and the third is a card you have taken out of the deck, leaving one ace that could give you a set rather than two. Four of a suit loses flush cards in the same way.
Hi-Lo uses it twice
In Omaha Hi-Lo (8 or better) the rule applies to the high hand and the low hand separately. Each is two from your hand and three from the board, and you may use a different two for each. That means a low needs three board cards of different ranks, all eight or under. If the board does not have them, there is no low for anyone and the high hand takes the whole pot.
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