The game lasts 13 turns. Each turn you roll five dice up to three times. After the first roll you can hold any dice (they stay put) and reroll the rest. Then you must score the dice in one open category of the scorecard, even if it scores 0. Every category is used exactly once.
\nDice positions are numbered 1 to 5 from left to right. hold 1 3 5 holds exactly dice 1, 3 and 5 (the others are released) and roll rerolls every die that isn't held. Shortcuts: roll keep 1 3 5 sets the held dice and rolls in one command, and reroll 2 4 rerolls just dice 2 and 4. Holds reset at the start of each turn.
Upper section: Ones to Sixes score the sum of dice showing that number. If the upper section totals 63 or more (three of each number), you get a +35 bonus.
\nLower section: 3 of a kind and 4 of a kind score the sum of all five dice when at least 3 or 4 dice match. Full house (three of one number plus two of another) scores 25. Small straight (four in a row, like 2-3-4-5) scores 30. Large straight (five in a row) scores 40. Yacht (five of a kind) scores 50. Chance scores the sum of the dice.
\nYacht bonus and Joker rule: if you roll another Yacht after scoring 50 in the Yacht box, you get a +100 bonus. Whenever you roll a Yacht and the Yacht box is already filled (with 50 or 0), the Joker rule applies: you must score it in the matching upper box (Fours for five 4s, and so on) if that box is open. If it's filled, you may use any open lower box, and Full house, Small straight and Large straight score their full 25, 30 or 40. If the lower section is full too, you must put 0 in an open upper box.
\nCategory names for score: ones (1s), twos (2s), threes (3s), fours (4s), fives (5s), sixes (6s), three-kind (3k), four-kind (4k), full-house (fh), small-straight (ss), large-straight (ls), yacht (y, yahtzee), chance (c).
Score: your final scorecard total, including the upper bonus and Yacht bonuses. The board always shows what each open category would score right now. You can resign to end early and keep your current total.