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Getting A Better Handle On Gin Rummy Particulars
Knocking
When a player decides to “knock” in gin rummy, the play ends. He or she may do this on any turn, but only if the value of the unmatched cards left in his hand after he discards is not more than ten points. After knocking, the player lays one card on the discard pile and then spreads out his ten cards, which should be arranged into unmatched cards and melds. This is the “deadwood.” If a player has no unmatched cards and he knocks, he is “going gin,” and he gains an extra 25 points. Even if you are able to knock, you don’t have to make this move. You could keep playing in an attempt to better score. However, if you decide not to play to gin, you should knock as soon as you can.
The knocker’s opponent is then supposed to in turn arrange all of his or her cards into sets and lay them face-up. If the knocker has decided not to go gin, the opponent may discard unmatched cards. He or she would use them to expand the knocker’s existing sets, and would add a card to one of the melds (provided it was in the same suit or a consecutive card).
However, if the knocker has gone gin, his opponent is not permitted to discard any of his cards or expand the knocker’s set(s).
Also, the player who knocks is forbidden to lay down any cards on the opponent’s matched cards.
The game may also end if the stock pile has only two cards after the player who took the third card discards it and doesn’t knock. In this play, the game ends without a score and begins with the same dealer.
Scoring and Undercutting
If a player scores gin, he is awarded 25 points and the opponent’s deadwood. If the game ends any other way, players add up the value of their cards that do. In the case that the knocker has a lower count, he is awarded points equaling the difference.

When the total of the opponent’s deadwood is equal or lesser of that of the knocker, and a player knocks without getting gin, the opponent can “undercut” and score a bonus 20 points. The opponent is also awarded the difference between the values of the two players’ unmatched cards.
Game Score
The winner of the game is the first person to score 100 points or more. Players can also choose to play to 150, 200, or 300 points. The player who wins adds up his score and then includes a 100-point bonus for the game. If he hasn’t won any hands during play, he may double his entire score, which includes whatever game bonus he has received. This instance is referred to as a shutout or a “schneider.” To finish, the players both add 25 points to their scores per hand that they have won; this bonus is called a box, or a line.