There is a big blind and a small blind, and the action starts from the right of the big blind. Every player is dealt four cards, and they have the option of calling, raising or folding.
Once this betting round is complete, the flop is dealt, which is three community cards. There is another round of betting, then another community card is dealt, which is known as the turn. After this round of betting we see one final community card, known as the river. There is one last round of betting, then players still in the hand turn over their cards and the best five card hand wins.
However, in Omaha, to make a winning hand, you can only use two of your hole cards, and must use 3 of the community cards. So for example, if we had these hands:
And the community cards were:
Dan would win with three sevens, as Steve can only use two cards from his hand, thus can't make a club flush.
Omaha is very popular as a pot limit game, as well as a limit game. In pot limit, you can bet the current amount of the pot. It also is very popular as a hi-lo variant, known as O8, as to get the low hand, you need an 8 qualifier. So in the hand shown above, this would actually be a split pot if it was hi/lo, as while Steve wins the High with his trip 7s, his low hand would be 87542, while Dans would be 754A2. Both would take 50% of the pot.
Required Reading: Hi/Lo Split Poker by Ray Zee is a great game for the Hi/Lo player, as is Winning Omaha/8 Poker by Lou Krieger. How Good is Your Pot Limit Omaha by Stewart Reuben is the premiere Omaha book.
Online Availability: All variants of Omaha are best played at either Party Poker, Pokerstars, Royal Vegas Poker or get some Boss Network Rakeback and play at Fortune Poker.