Common Gin Rummy mistakes

The rules of Gin Rummy are simple, but the same mistakes come up often. This guide follows our Gin Rummy rules page: 20-point gin, 10-point undercut, aces low.

Meld mistakes

• Running mixed suits. A run is three or more consecutive cards of one suit.
• Running over the king. Aces are low only. A-2-3 works, Q-K-A does not.
• Using one card in two melds. A card belongs to only one meld. Pick the arrangement with the lowest deadwood.
• Making a set with two cards. A set needs three or four cards of the same rank.

Turn mistakes

• Discarding the card you just took from the discard pile. It’s not allowed on the same turn.
• Ending a turn with 11 cards. After drawing, you must discard to return to 10 cards.
• Knocking above 10 deadwood. A standard knock needs 10 or less after your discard.
• Taking a buried discard. Only the top card of the discard pile is available.

Scoring mistakes

• Allowing layoffs against gin. The opponent can lay off cards on your melds only after a knock. Against gin, their deadwood counts as it stands.
• Forgetting the undercut. If the opponent’s deadwood is equal or lower after laying off, they score the difference plus 10.
• Giving equal deadwood to the knocker. Equal deadwood is an undercut for the opponent.
• Mixing bonus systems. This page uses 20 for gin and 10 for an undercut. Some sets use 25 for both. Choose one for the whole match.
• Scoring melds. Melds earn nothing on their own. Only deadwood differences and bonuses score.

Strategy mistakes

• Holding face cards too long. They cost 10 points each in deadwood.
• Ignoring the discard pile. What the opponent picks up shows their plan.
• Knocking with no margin. A knock with 9 or 10 deadwood is easy to undercut.
• Waiting too long. Under this site’s house rule, the hand is cancelled when only two cards are left in the stock.