Gin Rummy

1. Each turn, draw one card — tap the face-down stock or the face-up discard — then tap a hand card to discard one.
2. Build melds: a SET is 3-4 cards of the same rank; a RUN is 3+ in a row of one suit (Ace low). Melded cards get a green ring.
3. Cards in no meld are "deadwood" (face cards = 10, Ace = 1). Your live deadwood count shows under your hand.
4. When your deadwood is 10 or less the Knock button lights up — knock to end the hand and score the difference; deadwood 0 is Gin (+20 bonus).
5. Watch out for the undercut: if the defender ties or beats the knocker's deadwood, the defender scores instead. First to 100 wins.

Tap the stock or discard to draw, tap a card to discard, Knock button to end the hand