Oklahoma Rummy is a variant of Gin Rummy, as such the basic rules are very similar to the rules of Gin Rummy itself. There are, however, a few important differences. The first difference is whereas Gin Rummy is intended to be a two player game, Oklahoma Rummy can be played with any number of players between two and four. This makes it popular for people who want to play in group games as opposed to head-to-head. The second difference is in the scoring system as players can score negative points in Oklahoma Rummy. The final difference is that the value of deadwood at which players can knock is not always ten (as it is in Gin Rummy). Instead this value is determined by the value of the upcard (the first card of the discard pile).
Oklahoma Rummy is played with a standard deck of 52 playing cards (no jokers). If two players are involved then each is dealt 10 cards, if three or four players are in the game then each player receives 7 cards. Following the deal, the dealer places the remaining cards face down in the middle of the table forming the stock pile. The top card of the stock pile is turned face up and used to start a separate discard pile next to the stock pile. This is the upcard. The value of the upcard is of little importance in Gin Rummy, but in Oklahoma Rummy it has a significant influence on the game and must be noted.
Play begins with the player to the left of the dealer and each turn consists of a draw (either a blind draw from the top of the stock pile, or drawing the visible card on top of the discard pile) and a discard (which requires a player to discard one card of their choice from their hand face up on the discard pile). The aim of the game is to make melds out of the cards in your hand. Each player works out their melds in secret, such that other players do not know what cards they have, how close they are to winning and what cards they need to do so. As with all Rummy games a meld comes in two forms, either a run or a set. A run is a sequence of three or more cards of the same suit in order (for example the 6, 7 and 8 of Diamonds). A set is three or more cards of the same rank (for example three Aces). Any cards that a player holds that are not part of a meld are called deadwood.
A game of Oklahoma Rummy ends when a player knocks. A player may knock when the value of the deadwood in his hand is less than or equal to the value of the upcard (the first card drawn from the top of the stock pile that was used to begin the discard pile). This is why the value of the upcard is so important in Oklahoma Rummy. If a player holds an Ace and a four as deadwood then they would be able to knock if the value of the upcard at the start of the game had been five or more. However, if the value of the upcard was less than five, that player would not be able to knock. If a player can meld all of their cards then obviously they can win the game regardless of the value of the upcard by “Going Gin”. Indeed, it is often played that if the upcard is an Ace, then the game can only be won by “Going Gin” (and not by being left with a sole deadwood Ace as you might otherwise expect).
As with ordinary Gin Rummy the knocker receives points based on the total amount of deadwood left in his opponents’ hands after they have laid down their own melds and laid off their cards onto the knocker’s melds as best as they are able, thereby reducing their deadwood. Of course, as there are more players in Oklahoma Rummy this can potentially be a much higher score. The player who knocks receives points to the value of the difference between their deadwood and all their opponents, plus an additional 10 bonus points. However, if a player has a lower deadwood count than the knocker, the knocker has been undercut and the undercutting player receives the difference in points between their deadwood and their opponents’ totals, plus an additional 10 point bonus. If a player achieves Gin, they obviously cannot be undercut and score the sum of all their opponents’ deadwood, plus a 20 point bonus.
The difference in the scoring system between Gin Rummy and Oklahoma Rummy is that losing players receive negative points equal to their personal amount of deadwood minus the value of the knocker’s deadwood. This means that, throughout the course of the game, a player’s overall score can go up as well as down. Oklahoma Rummy games are normally played up to 150 points.