The undercut in gin rummy

What is an undercut in gin rummy?

An undercut happens when a player knocks and the opponent ends up with the same or less deadwood. The knocker has ten or fewer points of unmatched cards; the opponent then lays off any cards that fit the knocker's melds, and if what remains is equal to or lower than the knocker's count, the knock has been undercut.

The opponent then scores the difference between the two counts plus an undercut bonus, usually 25; some tables use 10 or 20. The knocker scores nothing for the hand, and the hand counts as a win for the opponent when the box bonuses are added at the end of the game.

That is the risk of knocking early with deadwood still in hand. A player who goes gin cannot be undercut, because the opponent may not lay off against gin and there is no deadwood to beat.

In Score All you enter who went down and both deadwood counts after layoffs. The app spots the undercut and applies the bonus you set, so nobody has to compare numbers across the table.

Where it applies

Related: Gin rummy scoring

This rule is a switch when you set up a game, so the scoreboard applies it for you. All scoring rules →