Omaha Hold'em, frequently referred to as just "Omaha" is the second most-popular type of poker in the world after Texas Hold'em. This particular type of poker was once just one of many variations of Texas Hold'em, but eventually the variation became so popular that its nickname stuck, and it became a game in its own right. No one is exactly sure when or where Omaha came to be (but we're pretty sure that, contrary to popular assumption, it did not start in Omaha). Some people say the game started in Vegas, others Chicago, and while we don't have an exact timeline for Omaha's creation, we know that it must have been sometime around the 1970s, after Texas Hold'em's official launch into the poker world and establishment as a popular game. Nowadays, Omaha can mean either the high game (this is what it means for European players, unless otherwise indicated) or any of the other variants on the game, which is what you see in North America, where the variant of Omaha is likely to be specified so that players know which version they're playing. Omaha is the O in games of HORSE.
How Omaha is Played
Omaha Hold'em is a game with a community pot, much like Texas Hold'em. Due to the origins of the game, it's almost impossible to talk about Omaha without talking about the game from which it developed, as they're quite similar. The fundamental difference between Omaha and Texas Hold'em is that in Omaha, players are dealt four cards face down, rather than two. Each player in Omaha must use exactly two of the four cards in the hole and three of the community cards to make a hand. A typical game of Omaha goes like this:
All players are dealt four cards each, face down. Players bet (the betting schedule in Omaha is identical to that of Texas Hold'em). Three community cards are places on the table (the flop), face up. Players bet again. The turn is flipped onto the table. Players bet. Finally, the river comes down, with another round of betting.
What it Offers
Omaha has a lot to teach a player. If you're a new or recreational poker player who is often discouraged because you rarely get good hands, Omaha is the game for you-- with 9 cards to make into various combinations, it's hard not to get a good hand (or a bad one, if you're playing Hi-Low). If you're working on getting better at reading the various poker hands, you'll see far more possible combinations with Omaha than any other game. Given the number of cards on the board at any one time, it can actually be quite difficult to determine who has high or low, depending on how the cards fall. Few games will allow players to play with combinations and try to work the best possible hands as well as Omaha, and this allows for a lot of room for growth and development as a player.
This same opportunity for growth for weaker players can become a benefit for stronger players, as Omaha also happens to be the type of player that is most commonly played very poorly. With Omaha almost always offered in online casinos and live tournament settings, a strong player can rake up quite a bankroll while playing against less experienced players who are still honing their skills. Players who are strong in other types of poker may also find that Omaha offers them new challenges where other games do not: the peculiarity of Omaha's rules mean that one must be much more on one's toes when looking at nut hands, betting, and anticipating the best course of action.
Omaha Hi-Low is a split pot variant of Omaha Hold'em that is very popular and often finds a place in major tournament play. In this variant, half the pot goes to the person with the high hand, and the other half goes to the person with the low hand. As with other forms of Omaha, players must use exactly two of their hole cards. A player could potentially win both high and low. For example, if a player held AA23 in his hand and the board came down Ace of Clubs Ace of Diamonds 4 of Hearts 5 of Spades Jack of Clubs , he would be able to use Ace of Clubs Ace of Diamonds Ace of Hearts Ace of Spades Jack of Clubs as his high hand and Ace of Clubs 2 of Diamonds 3 of Hearts 4 of Spades 5 of Clubs as his low hand, and he would have the absolute nut for both high and low, making the entire pot his.
Omaha Hi-Low Split Eight or Better (Omaha 8) is a type of Omaha Hi-Low where, in order to get the low pot, players must have a hand where the highest card is an eight. Forty percent of hands of this particular variant will not have a low pot at all because it would require three of the community cards being eight or lower (since a player has to use exactly three community cards).
Omaha 7 and Omaha 9 are like Omaha 8, but with a different qualifier for the high card in the low game.
Courchevel is played like regular Omaha High, with one difference: One community card is turned up first, and then the four cards are dealt down to each player. This means that the players have a full five-card hand before the betting begins (although they can still only use two of the cards in their hand).
Six Card Omaha follows all the rules of Omaha, but with six cards in the hole instead of four. Other variations may have other numbers of cards (designated in the name of the variation). Six Card is the most common variant with a different number of hole cards.