Gin Rummy was created with the intention of being faster than Standard Rummy and related games. The rules are very easy to learn as it is simply a matter of the draw and discard, without the complications attached to displaying melds and laying off cards between turns. Both of these things are done at the end of a hand and Gin Rummy is often played without any kind of laying off making for a "quick fire" game.
Players: Typically just two players, however there are other Gin games that can accommodate 3 or 4 players.
Cards: One standard 52-card deck, with no jokers or other wild cards. Aces are always used as a low card with a value of 1.
The Deal: Each player is dealt 10 cards, and the next card is turned up to become the start of the discard pile.
During the turn-by-turn play of Gin Rummy there is no laying down of melds or laying off of cards onto other melds. The cards are held in the players had until they are ready to go out, at which point the player will display their melds and the other player will have the opportunity to lay off. The players turns prior to being ready to go out are basically just drawing and discarding cards, one at a time.
Draw: The player must take just one card either from the discard pile or the stock pile and add this card to the 10 cards that comprise his hand. The discard pile is face up so the other player will know what card he took. If that player chooses to take from the stock, his opponent will not see the card (since cards on the stock pile are face down).
After the player has taken one card, he must now study his cards and decide which one is the card he needs least of all – a card that is probably not in sequence with the rest or is the only one of its kind making it nearly impossible to form either a set or run. The next step is:
Discard: The player must then take this card out of his collection and put it on the discard pile, face up.
Note that according to official Gin Rummy rules the players draw in a special way during the first round. The person who did not deal out the cards has the first choice. He can take the face up card from the discard pile if he wants to. If not, the other player can take it and if the other player does not want it either, the person who did not deal gets the first chance to draw the top card from the stock pile.
Stock Pile Exhausted
The game ends if there are only two cards left on the stock pile and the player who took the third to the last card on the pile discards a card without knocking. In this situation, there is no winner and another round can begin.
End of Hand
The Gin Rummy game ends as soon as one player has formed all or most of their cards into melds (Sets or Runs) and lays them all down on the table or in a designated meld area on the table for his opponent to see followed by him or her discarding their last card to signal victory. When the player goes out in this manner, it is called "Knocking" – a traditional symbolic gesture to announce victory to an opponent. Today, it is customary to throw the final card on the table (traditionally face down) to signal victory.
According to the official Gin Rummy rules a player may only Knock if they have 10 points or less of deadwood (i.e. unmatched or unmelded cards). For example, he can knock if his deadwood is A-3-4 as the total value of those cards is 8 points, which is less that the 10 point minimum.
After a player knocks the other player must now expose his cards, placing his melds on the table. He is also allowed to take any of his deadwood (unmelded cards) to add to the sets or runs laid down by the knocker. For example, he might add a fourth card of the same rank to a group of three or more consecutive cards of the same suit to either end of a sequence. This is known as "laying off". The player may only lay off cards that are deadwood, not cards that he has already formed into melds. The player who knocked is not allowed to lay off any of his or her own deadwood cards, even if it would appear that thay become playable due to the other player's lay offs.
Knocking is not mandatory. A player can choose to continue taking turns even if their deadwood count is below 10. If the player is able to Knock when all of their cards are melded, plus one to discard, then instead of knocking they declare "Gin" and lay down their melds and discard. When a player has gone "Gin" they receive a 20 point bonus and the other player is not allowed to lay off any of their deadwood. This means that there is a big incentive to try for Gin instead of knocking as soon as you can.
Each player totals the value of their deadwood cards, based on the following values. Aces are always low (ranking below a 2) and therefore have a value of 1.
Knock Scoring: If the knocker has a lower deadwood count then he or she receives the difference between their deadwood and the other player's deadwood.
Undercut Scoring: If the knocker does not go Gin, and his deadwood tally is equal to or higher than his opponent, this means the knocker has been "undercut” . His opponent scores the difference between the two counts and also receives a bonus of 10 points. For example, the the knocker has a deadwood total of 8, and the opponent has a deadwood count of 3, the opponent receives a score of 15 (8 - 3 + 10) and the knocker receives no points.
Gin Scoring: A player who goes Gin scores a bonus 20 points, plus the opponent's deadwood count, if any. A player who goes Gin can never be undercut. Even if the other player has no deadwood, the player who goes Gin gets the bonus and the other player gets nothing.
Game Bonus: Players keep dealing the cards for subsequent hands until one reaches a score of 100 or other designated (pre agreed) target score. The first player to reach a score of 100 points receives a "game bonus" of 100 points.
Line Bonus: In addition, each player earns a 20 point bonus for every hand won. This is known as the line bonus or a box bonus. These are not counted towards the 100 points required to win a game of Gin Rummy.
Optional Rules and Variations
The following rules may be added to the standard game if players agree to the variation before the first player takes their turn. It’s not an all or nothing deal, the game participants can pick and choose which variations they like.
- No laying off: Some play Gin Rummy with no laying off and scoring happens as soon as a player knocks or goes gin.
- No discard of drawn card: It is common to not allow a player to discard the same card they drew from the discard pile at the start of their turn. In other words, be sure you really want the card before drawing it from the discard pile.
- Undercut and gin bonus: There are some variations on the bonuses given for going gin or for undercutting. The actual values don't really matter much, just agree before playing what they will be. Common values other than those mentioned above are 25 for the gin bonus and 20 for the undercut bonus.
- Blitz: If the loser of the game has won no hands at all then the result is called a "Blitz" or a "Schneider" and the winner's score and game bonus, but not the line bonuses, are doubled.
- Only Runs: In this variation of Gin Rummy only melds consisting of runs are allowed. Sets of 3 or 4 of a kind are not.