Yams

Goal

Fill the thirteen boxes of your scoresheet, scoring as many points as possible. Each player fills exactly one box per turn: the game therefore lasts thirteen turns.

How a turn works

• Roll the five dice. You are allowed three rolls in total.
• Between two rolls, tap a die to keep it: it slides onto the rail and will not be rerolled. Tap it again to put it back in play.
• After any roll, tap an empty box in your column: the possible points are shown there in gold. A box worth 0 is “crossed out”: tap it twice to confirm.
• Keyboard: Space to roll, keys 1 to 5 to keep a die.

The boxes

• Aces to Sixes: total of the dice showing the indicated value.
• Bonus: 35 points if the total of the first six boxes reaches 63 (for example three dice of each value).
• Three of a kind: three identical dice, total of those three dice.
• Four of a kind: four identical dice, total of those four dice.
• Full house: three of a kind and a pair, 25 points (a Yams also counts as a full house).
• Small straight: four consecutive values, 30 points.
• Large straight: five consecutive values, 40 points.
• Yams: five identical dice, 50 points.
• Chance: total of the five dice, no condition.

Modes

Against 1 to 3 AIs, with friends on the same device (2 to 4 players), or solo to beat your personal record.

About the AI

The AI exactly evaluates every way of keeping its dice by computing the probabilities of the remaining rolls (252 dice combinations, 462 possible selections). To choose a box, it weighs the points obtained against the future value of each box and the probability of earning the bonus; these values were tuned over thousands of simulated games. At the Master level, as soon as six boxes or fewer remain, the endgame is solved exactly by dynamic programming: the AI averages close to 237 points, the theoretical optimum of the solo game. On the last turn, it plays to win rather than to maximise its average. The lower levels look less far ahead and make plausible inaccuracies. The Hint button gives you the advice of the Master level.