Here are the rankings of poker hands from high to low. We've also included the odds of getting dealt these as pat hands in draw poker.
Royal Flush - (1 in 650,000)
A,K,Q,J, and 10 all of the same suit. All suits are equal. Therefore, if the impossible occured and two people were dealt royal flushes, the pot would be split.
Straight Flush - (1 in 70,000)
Five cards in sequence and all of the same suit. The hand with the highest ranked card would win if more than one straight flush was shown. The cards cannot "turn a corner," for example 4
would not be a valid straight flush.
Four of a Kind - (1 in 4,000)
Four cards of the same rank. This hand is also known as quads.
Full House - (1 in 700)
Three of a kind, plus a pair. When full house hands, the hand with the higher ranked three card set wins.
Flush - (1 in 500)
Five cards of the same suit. When comparing flush hands, the hand with the higher ranked three card set wins.
Straight - (1 in 250)
Five cards in sequence. (Ace can be high or low). The lowest kind of straight would be 5, 4, 3, 2, A.
Three of a Kind - (1 in 50)
Three cards of the same rank. If you have to compare two threes of a kind where the sets of three are of equal rank, then the higher of the two remaining cards in each hand are compared, and if those are equal, the lower odd card is compared.
Two Pair - (1 in 20)
Two cards of one rank and two cards of another rank. When comparing hands with two pairs, the hand with the highest pair wins, irrespective of the rank of the other cards. If the higher pairs are equal, the lower pairs are compared. Finally, if both pairs are the same, the last cards are compared.
One Pair - (1 in 2.5)
Two cards of one rank - aces are high. If hands are equal on the pair, compare then next highest card. If there is still a tie, compare the next highest card. Finally, if the fourth card is equal, then go to the fifth for the tie breaker. If the hands are still equal, the pot is split.
High Card - (1 in 2)
In this case there are no better hands and the Jack is the highest ranked card. The hand would be called Jack high.
When playing low poker or lowball, there are some variations in rules, so these should be discussed in advance. Some general agreements are that flushes and straights don't count as high hands and aces are low (below the 2).