How to play Pig: the hold-at-20 rule

Pig has one decision: roll again, or hold. Making that decision well is the whole game.

The rules

On your turn, roll one die as often as you like, adding up the numbers. Roll a 1 and you lose everything from that turn. Hold to bank your turn total and pass the die. First to 100 wins.

Hold at 20

Each roll has a 1 in 6 chance of a 1, which costs your whole turn total. The average gain from a good roll is 4 points. When your turn total reaches about 20, the expected loss (20 × 1/6, about 3.3) starts to match the expected gain (4 × 5/6, about 3.3). So holding at around 20 is a strong simple strategy.

When to break the rule

• Close to 100: if a smaller amount wins the game, hold as soon as you reach 100.
• Way behind: if your opponent is near 100, banking 20 won’t be enough. Keep rolling for a big turn.
• Way ahead: you can hold a little earlier and play safe.

A game for learning

Pig is often used in classrooms to teach probability. Try playing a few games holding at 10, then 20, then 30, and see which wins most.