What is Knocking in Gin Rummy?

Short Answer
Knocking ends the round when your deadwood (unmatched cards) totals 10 points or less. After you knock, your opponent reveals their hand and can lay off cards onto your melds. The player with less deadwood scores the difference.

How to Knock

  1. Draw a card as normal
  2. Arrange your hand into melds (sets and runs)
  3. Verify your remaining deadwood is ≤10 points
  4. Discard one card face-down and declare "Knock"
  5. Lay out your melds and deadwood for your opponent to see
Example

Your hand: 4-5-6♥ (run), 9-9-9♠♦♣ (set), plus 3♠ and 5♦. Your deadwood is 3+5=8 points. You can knock!

When to Knock

The Risk: Undercuts

If your opponent's deadwood equals or beats yours after laying off, they score an undercut bonus of 25 points plus the difference. This is why knocking with high deadwood (8-10) can be risky.

Knocking vs. Going Gin

Action Requirement Opponent Layoff Bonus
Knock ≤10 deadwood Yes None
Gin 0 deadwood No +25 points