In casinos, you’ll find several different variants which are called “Omaha”. Besides the traditional version of the game, you’ll find a game called Omaha hi/lo, which is sometimes called 8-or-better or simply Omaha/8. The pot limit version, which is the “O” in H.O.R.S.E., is abbreviated to PLO.
Just like Texas hold’em, all versions of the game are played with five community cards. Like holdem, the cards are dealt in three rounds, which are the first three cards (“the flop”), the fourth card (“the turn”), and the fifth card (“the river”). These community cards are used by every player at the table. They are combined with a set of cards dealt to each player to help make up the best five-card hand possible. In Omaha, three and only three of the community cards are used for the final hand. In Texas holdem, a player could use the five community cards to make a best hand, if it fell that way.
The major departure from Texas holdem is the hand dealt to the player. Instead of receiving two hole cards, the player is given four hole cards. Once again, they player must use two and only two of these cards to build the best hand. If a player was dealt four aces as their hole cards, that player could only use two of them to build their hand. Thus, a hand must be comprised of 2 of 4 dealt cards combined with 3 of 5 community cards. This can be tricky to new players, who when they first begin playing might see three to a straight or three to a flush and bet according to that reflex (and most likely lose).
Another difference between the more famous holdem game and Omaha is the strength of hands. Because every player at the table receives four cards, the likelihood that one of the players holds a strong hand is much higher. Players bluff at extreme risk, while marginal hands can be deadly in the game. In fact, hands considered strong in Texas hold’em are likely to be dominated in this game.
As you can see, the two games are similar enough that an experienced player of holdem could immediately start playing Omaha poker and know how the deal, blinds, and betting rounds would be like. Yet they would not be able to master the game without a lot of in-game experience playing this variant.
Because of the likely stronger hands, Omaha poker is considered a game of the nuts. Players who aren’t holding “the nuts”–that is, the strongest possible hand in a given situation–are likely to lose a showdown. This is obviously a radical departure from Texas holdem.
The hi/lo version of the game offers yet another level of challenge. In this game, half of the pot is divided by the player with the highest hand and half the pot is given to the player with the lowest hand. So, players would bet on their ability to fill out a strong hand, like they would in the main version of the game. They would also have to consider whether they held good cards to win the low as well. Competitors need to be able to think through a lot of different scenarios to excel at PLO.
The most common form of the game (the form always played in Europe by default) is the pot limit game. This might be new to people who are used to no-limit games only. No-limit is rare in land-based casinos outside the USA, but almost always available at online poker rooms.
One other rule needs to be pointed out about the high/low variant. In order for a hand to qualify for the low, the hand cannot contain a card higher than an 8. In Omaha 8 or Better, if you were dealt 2-9-Q-K, you wouldn’t even be able to qualify for the low pot because one of the cards from your hand would have to be higher than an 8. The player must be able to play a hand that is 8-7-6-5-4 or lower (straights don’t count in the low game). A player who was dealt a 2-9-K-A would be able to qualify, though, since the hand could be read as A-2-9-K, with the ace as 1. For this reason, aces are particularly important in Omaha 8 or Better. On occasion, you’ll have a hand where no player at the table qualifies for the low hand, due to the 8-high rule. In the event this happens, then the whole pot is won by the player with the highest hand.
A common question about the rules for ending a round of Omaha goes something like this: “Are players supposed to choose between building the low hand and building the high hand?” Put another way, it is common for a newcomer to ask “Is it possible for both pots in a split pot game to go to the same player?”
Not only is it possible to win both pots, it is the ideal endgame for every player in every round. Using any two dealt cards for the high hand and any two for the low hand, the best possible outcome each round is winning both the high and low pots.