Shut the Box

Yes, because they add up to the roll. With a 2 and a 5 you can shut the 2 and the 5. You can just as well shut the 7, the 1 and the 6, the 3 and the 4, or the 1, the 2 and the 4. What the single dice show does not matter, only their sum.

As many as it takes to make the sum. A 10 can be paid for with four tiles: the 1, the 2, the 3 and the 4. No sum that two dice can make needs more than four.

No. Each number exists once. A double 4 is an 8, and it has to be paid for with tiles that are still open and add up to 8. The 4 can be one of them only once.

When the 7, the 8 and the 9 are all shut. Then the words Roll one on the green field get a chalk frame, and you may pick either before each roll. You never have to roll one die here.

No. One die can never make more than 6. If your open tiles add up to more than that, a single die cannot shut them all in one go, and two dice often shut more. For shutting the box, the exact rule is short: roll one die when the open tiles add up to 6 or less, and two dice otherwise.

The clearest case is a lone 1. Two dice cannot roll a 1, so only a single die can shut it, and it does so one time in six.

A little under one round in ten, at best. Played perfectly with nothing in mind but shutting the box, a round ends with all nine tiles down 9.76 percent of the time. Without the one-die rule it is 7.14 percent. With twelve tiles and two dice it falls to 0.36 percent, about one round in 280.

Playing for the lowest score instead, perfect play leaves 11 points open on average.

Barely. The side that plays second knows the score to beat and can aim for it. The side that plays first wins at once if it shuts the box. With perfect play on both sides the two nearly cancel out: the first side wins 50.15 percent of the games, counting a draw as half a win.

Yes. If both sides leave the same sum open, nobody wins. A draw is counted as a draw in your record.

No. A roll stands. Undo here takes back your choice of tiles and gives you the same roll to pay for another way, and it works until you roll again. Tiles you have picked but not yet shut go back with another press on them.

Mostly luck. You choose which tiles to shut, and later whether to roll one die or two. Everything else is the dice. The levels on this page show how much the choosing is worth: the best level here beats the weakest in 87 games of 100, and beats the next best in 55.

Nobody knows for certain. It is a pub game. A British trade paper of 1967 called it a game from the Channel Islands that had reached the pubs of Manchester, and older origins are claimed without much proof. In the United States the television quiz High Rollers was built on it in the 1970s.

No. Every roll comes from the same source, whoever's round it is, and the computer is never shown a roll before it is on the lid. How the dice are made is further down this page.

Low tiles are useful for a long time, because small numbers fit into many sums. The 9 fits into few, and only a roll of 9 or more can shut it. So when a roll can be paid for with one high tile or several low ones, take the high tile. A 9 is better spent on the 9 than on the 4 and the 5.

Every tile you shut is one fewer way to pay for a later roll. Shutting the 1, the 2 and the 3 for a 6 leaves you with no small change at all. The weakest level here plays exactly like that, and it is why it loses.

Seven is the most common roll of two dice: 6 of the 36 ways the dice can fall. Sixes and eights come 5 times each, and a 2 or a 12 only once. A set of open tiles that can pay for a 6, a 7 and an 8 will survive nearly half of all rolls on those three numbers alone.

With the 7, the 8 and the 9 shut, count what is still open. If it adds up to 6 or less, one die gives you the best chance of shutting the box. If it adds up to more, two dice usually keep the round alive longer.

When you play second, it also depends on the score you have to beat. If you are already under it, nothing more can go wrong, and the only reason to roll on is the pleasure of it.

The computer's score is chalked above the box when your round begins. Needing to get under 5 calls for other choices than needing to get under 20. Close to a low target, keep the tiles that the next roll is most likely to need. Far ahead of it, anything works.

The Hint button shows what the computer would do at full strength: which tiles to shut for the roll on the lid, or whether to roll one die or two. It counts the whole game, your opponent's score included, and not just the next roll.

Shut the box is small enough to be solved outright. Nine tiles can be open or shut in 512 ways, and from each of them every roll and every legal answer can be followed to the end of the round. The engine does that, and so it knows the exact chance of winning after every possible choice.

Playing first, it counts what the other side is likely to do with its round. Playing second, it knows the score it has to beat and plays for that and nothing else.

The numbers match those published for the game: 9.76 percent for shutting the box with the best play, and 7.14 percent when two dice are always rolled. All of it happens on your own device, in your browser.

Shuts as many tiles as it can for every roll, the lowest ones first. It runs out of small tiles early, and after that almost no roll can be paid for. It always rolls two dice.

Shuts the two tiles that the dice show. When it cannot, it uses as few tiles as possible, with the highest one that fits. The high tiles are left open far too long. It always rolls two dice.

Takes the 7, the 8 or the 9 whenever the roll is one of those numbers and the tile is open. Otherwise it plays like Easy.

Follows the old rule: as few tiles as possible, the highest first. Its one fault is the single die, which it rolls the moment it is allowed instead of when it pays.

Works out the exact chance of winning for every choice and takes the best one. It cannot be outplayed, only outrolled.

These are not measured by playing games. The game is small enough for the result between two levels to be worked out exactly, over every way the dice can fall. Each figure is the average of playing first and playing second, with a draw counted as half a win.

• Easy against Beginner: 68.1 percent.
• Medium against Easy: 59.0 percent.
• Hard against Medium: 59.8 percent.
• Expert against Hard: 55.3 percent.
• Expert against Beginner: 86.7 percent.

This is a game of luck. Perfect play wins only 55 games in 100 against the old rule of thumb, and it still loses about 13 in 100 to a level that throws its small tiles away. Worked out on 9 October 2026.

The Hint button asks the engine at Expert's strength. In this game that is the best move there is, not just the computer's best guess.

When a game starts, the page draws one random number. Every roll in that game is worked out from that number and the number of the roll: the first roll of the game, the second, and so on, whoever makes it. The code that makes the roll does not know which side it is for.

The computer is handed the tiles and the roll that is on the lid, and nothing else. It never sees a roll that has not been thrown yet, its own included. A roll is never taken back either, so there is no way to fish for a better one.

On 9 October 2026 the generator was run for 2 million rolls of six dice, 12 million dice in all. Each of the six faces came up between 16.65 and 16.68 percent of the time, where a perfect die gives 16.67. The average die showed 3.500 on odd-numbered rolls and 3.499 on even-numbered ones, against the 3.5 that fair dice give.

A round is short: a handful of rolls, and never fewer than four to shut the box. One awkward roll at the wrong moment decides it, and over time it comes for both sides equally often.

With the 1 and the 2 left open, 33 of the 36 rolls of two dice end your round. Only a 2 or a 3 keeps it going. Whether that happens to you or to the computer in a given game is luck. Over many games it evens out, and what is left is the few percent the choices are worth.