There are numerous theories out there about what hands people should play in
Omaha 8 including point systems that take into account each of the cards you hold in your hand. However, it's much easier than that, especially when playing at the lower limits. Here are the hands you should play and why:
* Any hand containing four cards lower than a 5. Hands like 2-3-4-5, A-3-4-5, or A-2-3-4 are very strong hands in Omaha 8 because they are premium low hands that provide you with something called counterfeit protection. One of the problems with playing a hand like A-2-x-x is that while you will often be drawing to the nut low if low cards come, if a 2 comes, your low will be no good... it will be counterfeited. Having the backup of two other low cards provides you protection. Additionally, these connected cards will often provide you with ways to win the entire pot with straight possibilities.
* A-2-x-x hands. In unraised pots, these hands should be played every time. In raised pots, you need to proceed cautiously. In fact, it would not be a mistake to fold A-2-x-x in a raised pot when you are out of position because what will often be the case is that you will be facing other people with A-2-x-x and the best you can do is chop the low end of the pot. It's one thing to play for ½ the pot... it's quite another to only play for ¼ the pot. A-3-x-x are also playable but you will often be looking at winning nothing if someone has A-2-x-x so typically you want other ways of winning some of the pot when you play an A-3-x-x type of hand.
I Four cards ten or higher, especially if two of them are suited. These are hands like K-Q-J-10, K-Q-Q-J, and A-Q-J-J. These are very powerful hands in Omaha 8 because they are “high only” hands. They can only win the high hand but if no low cards come and people have been chasing the low you can win the entire pot. For example, you play K-Q-J-10 and the flop comes A-Q-10, you make a bet and someone with A-3-4-6 calls you hoping to hit the runner-runner low (a big mistake that we will talk about soon). The turn is a 6 and they pick up a low draw to go with their two pair. He gets into a raising war with you and the river is a jack. It doesn't change anything for you but you've won a big pot. One of the truths of Omaha 8 is that people will chase the low. Way too much. Playing high only hands is how you can punish this tendency.
* Big pair hands with backup. These are hands like A-A-6-5 with one of the aces suited, or K-K-3-2, or Q-Q-5-4 double suited. Single pair hands don't have the same value they do in hold'em and often people will overplay hands like A-A-9-6 thinking “I have a pair of aces, this is the nuts, I have to bet it.” While you probably want to see a flop with an A-A-x-x or K-K-x-x type of hand, you want to minimize the amount of money you put in pre-flop unless you have backup. Backup is other cards that give you ways of winning the entire pot. With a hand like A-A-6-5 with one of the aces suited, you can also win the pot with a non-nut low, have some straight possibilities, or can hit a flush. Big pairs are good. Big pairs with backup are even better.