Players & Deck – Gin Rummy has different versions which differ in terms of the rules followed. It is basically a two player game but in different versions up to four players can play. A deck of 52 cards with no wild cards is used. The turn to deal the cards changes after every hand.

The Deal – The dealer deals 10 cards to each player. After the distribution of the cards is done the next card that comes on is put face up on the table to start of the discard pile. The remaining cards are put face down on the table and this stack is generally referred to as a stock pile.

The objective of the game is to form the complete hand into Sets and/or Runs. A Run (sequence) is group of three or more successive cards of the same suit and is shown in the example below:

A Set, on the other hand, is a group of three or four cards of identical rank and of different suits, as shown in the example:

A particular card can be used to make either a Run or Set but the same card can never be used for forming both.

The two major things involved in the game Gin Rummy are drawing and discarding and they are discussed below:

Drawing (Compulsory) – The player to the dealer’s left picks a card first either from the discard pile or the stock pile and adds to his hand. When the player claims a card from the discard pile other players know which card he/she picked and this is not a case when the player picks from the stock pile, hence better concealing his hand on not letting the opponent make a note of the cards he/she has picked. The player when want to pick a card from the discard pile can take only the top card.

The player now on picking a card goes over the hand to see which card he needs the least and discards it. This phenomenon is discussed below:

Discarding (Compulsory) – This process of discarding is compulsory in Gin Rummy and the discard is put on the discard pile face up. The player can go out to win the game only on discarding a card.

According to official Gin Rummy rules the players draw in a special way during the first round. The person other than the dealer gets first chance to pick the face up card from the discard pile if he wishes to. If this player does not go for the card, the next player can pick it and if this player too rejects, the person who did not deal gets the first chance to draw the top card from the stock pile.

The player in Gin Rummy wins the game having melded his cards (Sets or Runs) and laying off them on the table with finally discarding his last card. The official Gin Rummy rules allows a player to Knock the play only if they have 10 or less than 10 points of deadwood (unmeld cards) count. An example as when a player can knock is shown here:

If a player has the hand remained with cards A 2 4, as the the total deadwood count here is 7 points which is less than 10 points, he can go out or knock the play.

Knocking - The player’s win is customarily referred as knocking. The player puts the last discard face down as to declare his win. This is not an official rule and just habitually done. The other players now expose their cards on placing them on the table. The players are even allowed to add their cards to the melds of the knocker but they have to see that the meld even on addition of cards makes a valid meld. This is called as "laying off" which can be seen in the section below:

In Gin Rummy the players reveal their hand only at the end of the game unlike other rummy games where the player is allowed to place his melded cards on the table on his turn. Thus the player on knocking places his cards exposed on the table and the other players reduce their deadwood count laying off the cards on adding them to the already existing melds of the knocker. It is important to note that the knocker can never do this type of "laying off".

Knocking is not compulsory and in a case where the player melds his entire hand with no deadwood he can go out to win the game declaring "Gin", this is generally referred as "Going Gin". This gives him a bonus of 25 points in addition to the opponent’s deadwood count. The opponent now cannot lay off the cards and thereby failing to reduce his deadwood count. This proves to be an advantage not to knock until melding the complete hand.