A person or hand who is not mathematically favored to win a pot. For instance, if you flop four cards to your flush, you are not quite a 2:1 underdog to make your flush by the river (that is, you will make your flush about one in three times). See also "dog".
Omaha is considered, by some, to be the hardest game of Poker to master. Of all of the different games of Poker, Omaha is for many the hardest to learn to play and the hardest to bluff in. It is played most often at fixed limits, like Texas Hold'em and pot limit.