Gin Rummy

The table, the cards and what a meld is

Gin Rummy is played 2 against the CPU with a standard 52-card deck. Each card's point value is its own: an ace counts 1, cards 2 through 10 count their face value, and a jack, queen or king each count 10 — this one table is what deadwood, the knock limit and every settlement in the game add up from.

A meld is either a set — 3 or 4 cards of the same rank — or a run — 3 or more cards of the same suit in consecutive order. An ace is always low, so ace-2-3 is a run and queen-king-ace is not. Any card that doesn't belong to a meld is deadwood, and its point total is the number this whole game revolves around.

• Dealing gives each player 10 cards, one at a time, alternating from whoever isn’t dealing. The 21st card is turned face up as the upcard, and the other 31 form a face-down stock you draw from.
• Whoever won the previous hand deals next; the very first dealer for a match is chosen for you. There's no screen for choosing who goes first — the closest thing to a choice here is a coin toss, and the game already made the call.
• Difficulty — Easy, Normal or Hard — is set from the home screen, and it applies to your next match. Changing it never touches a match already underway; you finish that one against the opponent you started with.

Taking the upcard, then drawing and discarding

Whoever isn't dealing gets first right to the upcard: take it, or pass. If both players pass, the non-dealer draws blind from the stock and the hand is properly under way; the passed-up upcard isn't available again that turn either way.

From there each turn is draw, then discard: pull the top card of the stock or the top of the discard pile, then put one of your 11 cards back down. A card you just took from the discard pile can't be discarded again in that same turn — it closes off a free look at a card you didn't really want.

• Drawing is a single tap — there's only one stock and one discard pile, so there's nothing to mix up.
• Discarding takes 2 taps: the first lifts a card, the second puts it down, which keeps a crowded hand of cards from being discarded by accident.
• A card you can't legally discard just sinks and stops responding to taps. Nothing buzzes or plays a sound to tell you off — the game shows you what's allowed instead of scolding you for what isn't.

Knock, Gin and Undercut

After drawing, if the best possible split of your remaining 10 cards leaves 10 points of deadwood or less, you can knock instead of discarding — lay your 11th card face up on the discard pile, and the hand ends there. Zero deadwood on a knock is Gin, worth more than an ordinary knock.

Both hands are scored by their best possible split, not by the melds you happened to lay them out in — the game always finds the lowest deadwood available, whether or not that's the arrangement you were looking at. On a Gin, the loser can't lay off any cards, and the winner takes the loser's deadwood plus 25 points. On an ordinary knock, the loser gets to lay off — attach cards from their own hand onto the knocker's melds, stretching a run at either end or completing the 4th card of a set — before the deadwood is compared.

• If the knocker's deadwood is strictly lower after layoffs, they take the difference.
• If the knocker's deadwood is equal to or higher than the opponent's, that's an Undercut: the opponent takes the difference, plus 25 points. A tie counts as an Undercut too — knocking doesn't pay unless you actually come out ahead.
• Every card's placement is decided all at once, both which cards to lay off and which meld each goes on — a greedy card-by-card assignment can leave points on the table that a single simultaneous search finds.

Dead hands, and winning the match

A hand can also end without anyone scoring. Once the stock is down to 2 cards after a discard, nobody can draw for the next turn, so the hand is declared dead: no points change hands, and the same player deals again. Reaching 2 cards in the stock doesn’t stop a knock, though — a knock that lands first always beats a dead hand, even on the very turn the stock runs out.

The match itself is a race to 100 points. Whoever gets there first wins outright — there's no draw in Gin Rummy, since only one side can reach 100 first. The screen shows the final score and the hand that decided it, and the next match doesn't cost anything to start.

• Deadwood and the match score sit at the top of the screen the whole time — not to rush you, just to say where things stand.
• Only a match that actually finishes counts in your record. Starting over mid-match doesn't add a loss for the one you left.

Easy, Normal and Hard

There are 3 opponents, and every one of them is built from the same heuristics rather than a lookahead search — the heaviest calculation any of them does is working out the single best split of an 11-card hand, and that's cheap even by brute force. The difference between the 3 is what each one looks at, not how long it thinks.

Whatever the difficulty, the CPU only ever sees what's actually public: its own hand, the discard pile, the stock's card count (never its order or contents), and how many cards you're holding. It can't see your hand and it can't see what's left in the stock — nothing about a stronger opponent changes that.

• Difficulty is chosen from the home screen and all 3 are available from the first launch — none of them unlocks by playing or paying.
• The CPU's reply lands after a short pause, about 450ms for drawing and another 450ms for discarding, so you see what it took before you see what it put down.

Gin — 0 deadwood — is taken at every difficulty without exception, since there's no reason to pass up a hand worth 25 points that can't be laid off against. What Easy doesn't weigh is the other side of that coin: knocking at 10 can hand back 25 points the other way if it gets undercut, and Easy doesn't know that.

Undo, and the help this game actually gives

There's no Undo here, and that's not an oversight. On the 4 games where taking a move back exists, both sides always see the same board — undoing removes a decision, nothing more. This game has cards nobody else can see: watching what the CPU took, then stepping back, would let you keep something you can't legally know when the position resets. What Undo would take back is your move; what it can't take back is what you learned.

There's no Hint either. Deciding what to draw, what to discard and when to knock is the entire game — a suggested move would just be the game playing your hand for you instead of its own.

• Your hand always sits sorted into its best possible split of melds automatically, with a color bar down each card's edge marking where one meld ends and the next begins. There's no manual rearranging, because the arrangement you'd be rearranging is already the best one there is.
• Your current deadwood total is shown at all times — adding it up is arithmetic, not skill, so the game does the arithmetic for you.
• The Knock button simply isn't there until you're actually able to knock. An absent button is the message: no greyed-out control sits around telling you no.
• All 3 of these are free from the first launch, and no game feature is ever behind an ad or a purchase.

Tips

• Watch what the CPU picks up from the discard pile, not just what it throws away — a card it took tells you a rank or suit it's building toward, which is public information you're allowed to use.
• Early on, hold cards that connect to 2 or 3 possible melds rather than committing to one combination — a card that could complete either a run or a set is worth more than one that only helps a single plan.
• Discarding a card near the rank or suit of something the CPU has already picked up hands it a hint you didn't have to give. On Hard especially, that's exactly the pattern it's watching for.
• Knocking as soon as you're under 10 isn't automatically right — if the CPU can lay off heavily onto your melds, a small knock can turn into an Undercut. Waiting for Gin, or a much lower deadwood, is sometimes worth the extra turns.
• Near the end of the stock, weigh a modest knock against the risk of a dead hand: once the stock reaches 2 cards, an unfinished hand scores nothing at all, so a safe 8 or 9 point knock can beat holding out for Gin that never arrives.

Questions people ask