Omaha

Omaha is a family of poker variants in which each player receives four cards and uses two of them, plus three of five community cards, to make a hand. It is most often played in the following forms:


 * Fixed Limit Omaha hi-lo
 * Fixed Limit Omaha high
 * Pot limit Omaha high
 * Pot limit Omaha hi-lo

History
Bob Ciaffone states in his book Omaha Holdem Poker that the game now known as Omaha started as a collection of very similar home-games played across the US (with one notable exception being the bustling metropolis of Omaha, Nebraska). He then goes on to state that:

"Regular holdem was actually played in two forms in Nevada: the popular Texas variety where a player uses any five of the seven cards available, and the rare form where he must play both cards in his hand. This rare form was called Omaha (and is currently called Greek holdem for some reason). Therefore, Nevadans already used the word Omaha to mean that both cards in the hand must be used at the showdown. When the game of four-card holdem was introduced, it was called Omaha in Las Vegas to emphasize the fact that precisely two cards in the hand were to be used. Nevada sets the fashion for the rest of the nation, and indeed the world, where gambling matters are concerned. So we finally have one international name, Omaha, to describe this four-card game of the holdem family that had acquired so many local names during the 70's and early 80's."

Alan Bostick has done a significant amount of research on the history of Omaha, some of which can be found in this |this rec.gambling.poker post, and more can be found in the comments to this excellent blog entry.