About Pig Dice
Pig is a push-your-luck dice game with only one die and one rule that bites: roll a 1 and you lose everything you gained that turn. You race the computer to 100 points, deciding after every roll whether to risk another or bank what you have.
How to play
- You and the computer take turns, and you always go first. The first player to reach 100 points wins.
- On your turn, roll the die as many times as you like. Each roll of 2 to 6 is added to your turn total.
- If you roll a 1, your turn total is lost and the turn passes to the computer.
- Press Hold at any time to add your turn total to your score and end your turn. You must roll at least once before holding.
- As soon as your score plus your turn total reaches 100, the points are banked automatically and you win; there is no need to hold.
- The Wins counter tracks how many games you have won, and your Best is the highest number of wins you have reached.
Controls
- Press Roll to roll the die and Hold to bank your turn total.
- The bars at the top show each player's banked score, with the current turn total shown in brackets.
- Both actions are normal buttons, so mouse, touch and keyboard (Tab and Enter) all work.
Tips and strategy
- Holding at around 20 is a good rule of thumb. Below 20, the average gain from another roll is larger than the average loss from rolling a 1.
- When you are well behind, take more risk. Steady 20-point turns will not catch an opponent who is close to 100.
- When you are close to winning, do not stop just short; keep rolling until you can reach 100, since your total banks automatically when you get there.
- If the computer is close to 100, it will probably finish next turn, so consider rolling on for more than 20.
- Do not let a run of good rolls change your plan. Each roll has the same one in six chance of a 1.
Background
Pig is a folk dice game that was described by the game writer John Scarne in 1945, and it is often used in classrooms to teach probability. The hold at 20 rule comes from a simple calculation: rolling again gains about 20 divided by 6 points on average, while risking the whole turn total with a one in six chance, so rolling is worthwhile while the turn total is below 20. Researchers Todd Neller and Clifton Presser later computed truly optimal play for Pig to 100, which also adjusts for the score of both players.
Questions
- How does the computer play?
- It keeps rolling until its turn total reaches 20, or until it has enough to reach 100, and then holds. It does not adjust for the scores, so you can outplay it late in the game.
- Do I always go first?
- Yes. You roll first in every game, which is a small advantage.
- Can I play against a friend?
- Not in this version. Pig is always played against the computer here.