Gin Rummy

Scoring

If the knocker's unmelded cards add up to fewer points than the opponent, the knocker scores that point difference.

A player who goes gin earns a 25-point bonus, in addition to the value of the cards in the opponent's hand.

Undercut

If the opponent has points equal to or less than the knocker's, however, the knocker has been "undercut," and the opponent earns the difference in the points in the hands plus a 20-point bonus.

Big Gin

If all 11 cards in a player's hand can form a meld prior to knocking, the player will earn a Big Gin bonus of 6 points when he or she knocks.

Endgame

The first player to get a total of 100 points wins the game.