Play Can't Stop Online

What Is Can’t Stop?

Can’t Stop is a push-your-luck dice game for two to four players in which you race white runners up eleven columns numbered 2 through 12. Each turn you roll four dice, split them into two pairs, and move a runner one step in the column matching each pair’s total. You have only three runners, and once all three are on the board every roll must produce a pairing that hits at least one of their columns. Miss, and you bust: the runners come off, and every step they climbed that turn is gone. Stop in time, and your own colored markers take their places for good. Reach the top of three columns and you win.

What makes Can’t Stop the standout of its family is that the risk is never fixed. In Pig a roll of 1 always ends your turn and in Farkle the bust chance depends only on how many dice you hold. Here it depends on which columns your runners occupy, and you choose those columns. Runners on 6, 7 and 8 bust on 8 percent of rolls; runners on 2, 3 and 12 bust on more than half. The board itself, with its short outer columns and 13-step column 7, is a physical picture of the bell curve of two-dice sums that also drives Craps.

A Short History of Can’t Stop

Can’t Stop was designed by Sid Sackson (1920 to 2002), the New York game inventor whose A Gamut of Games (1969) and Acquire (1964) made him the most respected American designer of his generation. German sources trace the idea to a paper-and-pencil race game Sackson published in the mid-1970s, but the board game as we know it was first published by Parker Brothers in 1980, with its distinctive stop-sign-shaped board, plastic cones for markers and three white “runners.”

The game did not sell well in the United States and Parker let it go, but it found a lasting home in Germany. A German Parker edition appeared in 1981 and was placed on the Spiel des Jahres jury’s recommendation list, where the jury noted that Sackson “proves that he also knows how to use dice.” Franjos Spieleverlag took over the German license in 1991 and gave the game its now-familiar mountaineering theme, with climbers scaling a peak in place of Parker’s abstract columns; Franjos reissued it in 2005 and has held the license again since 2011. Ravensburger licensed a multi-language edition in 2007, the same year Face 2 Face Games brought it back to North America. Today the English-language edition comes from Eagle-Gryphon Games, whose 2021 printing replaces the plastic board with a neoprene mat and wooden markers. Playdek released an iOS version in 2012.

Michael Keller’s Rule of 28, published in World Game Review in 1986 and revised in 1998, is the best-known stopping heuristic, and it is what the computer opponent on this page uses.

Can’t Stop Rules

Components

• A board with eleven columns numbered 2 through 12. The columns are 3, 5, 7, 9, 11, 13, 11, 9, 7, 5 and 3 steps long, so column 7 is the tallest and columns 2 and 12 the shortest.
• Four six-sided dice.
• Three white runners (neutral markers shared by everyone).
• Eleven colored markers per player, one for each column.

Object

Be the first player to claim three columns. A column is claimed when your marker sits on its top step.

How a Turn Works

1. Roll all four dice.
2. Split them into two pairs. Every roll can be paired three ways. For example 2-3-4-5 can be 2+3 and 4+5 (columns 5 and 9), 2+4 and 3+5 (6 and 8), or 2+5 and 3+4 (7 and 7).
3. Move runners. For each pair total, advance a runner one step in that column. If you have no runner there yet, place one on the step above your own marker (or on the first step if you have no marker). You have only three runners: if the pairing you pick needs more runners than you have left, you may move just one of its totals. If both totals can be moved, you must move both. Doubled totals, such as 3+4 and 2+5 both making 7, move one runner two steps.
4. Decide: stop or roll? If you stop, replace each runner with your marker on the step it reached. If you roll, repeat from step 1.
5. Bust. If no pairing can move any runner, your turn ends, the runners are removed and your markers stay where they were before the turn began.
6. Claiming a column. When a runner reaches the top step and you stop, the column is yours. Nobody else may use that number again; other players’ markers in that column are dead.

Ending the Game

The moment a player stops with markers at the top of three columns, that player wins. There is no final round.

Column Lengths and Single-Roll Odds

The “chance per roll” column is the probability that at least one of the three pairings of four dice adds to that number. Notice that 7 is not four times as likely as 2 even though its column is more than four times as long; that mismatch is the central tension of the game.

Worked Examples

• Roll 3-4-5-6, no runners out. The pairings are 7+11, 8+10 and 9+9. The last one moves a single runner two steps up column 9 while using only one of your three runners. That is often the best pick early in a turn.
• Roll 2-2-5-5. Pairings: 4+10, 7+7 and 7+7. Either place runners on 4 and 10, or move one runner two steps on 7.
• Runners on 6 and 8, roll 1-2-3-4. Pairings are 3+7, 4+6 and 5+5. With 4+6 you move the runner on 6 and place your last runner on 4. With 3+7 you may place only one runner, and you choose which. With 5+5 you place the last runner on 5 and move it two steps.
• Runners on 6, 7 and 8, roll 1-1-1-2. Every pairing gives 2 and 3. Bust: all three runners come off.
• Runner on 7 at step 12. Any pairing containing a 7 lifts it to step 13, the top. Stop now and the column is yours; roll again and a bust would throw it away.
• Column 8 already claimed by your opponent, roll 2-6-3-5. The 2+6 and 3+5 pairing is dead on both totals; you must use 2+3 and 6+5 (5 and 11) or 2+5 and 6+3 (7 and 9).

Probabilities: The Bust Table

Every Can’t Stop decision comes down to one number: the chance that the next roll offers no legal move. Because only four dice are involved there are just 6⁴ = 1,296 outcomes, so the bust chance for any set of runner columns can be computed exactly, which is what the game on this page does before every roll.

Bust chance for three runners

The safest set on the board is 6-7-8, and the worst is 2-3-12 or its mirror 2-11-12. Mixing odd and even columns matters as much as staying near the middle: 5-7-9 (all odd) busts almost twice as often as 6-7-8, and 4-6-8 (all even) is safer than 5-7-9 even though it sits farther from 7.

With fewer than three runners

While a runner is still free and unclaimed columns remain, you cannot bust: any pairing can place the spare runner somewhere. The danger begins only when the third runner is placed. That is why experienced players are relaxed about the first two or three rolls of a turn and careful afterward. The engine’s status bar shows 0 percent while you have a runner in hand and switches to the exact figure the moment you commit the third.

The Rule of 28

Michael Keller’s rule turns these probabilities into something you can count on your fingers. Give each step a value: column 7 is worth 1, columns 6 and 8 are worth 2, 5 and 9 are worth 3, 4 and 10 are worth 4, 3 and 11 are worth 5, and 2 and 12 are worth 6. A step taken by a newly placed runner counts double. Once all three runners are out, adjust the total: add 2 if all three columns are odd, subtract 2 if all are even, and add 4 if all three are 7 or below or all are 7 or above. When the count reaches 28, stop. Keller found that the rule lands within one roll of the correct stopping point in about 75 percent of positions and within two rolls in 92 percent.

Can’t Stop Strategy

1. Do not stop before your third runner is placed

A roll cannot bust you while you hold a spare runner. Stopping with one or two runners out wastes free rolls, and the Rule of 28 explicitly forbids it. The only exception is a runner sitting on the top step of a column you badly need.

2. Aim for two columns near the middle and one that mixes parity

Runners on 6, 7 and 8 bust 8.0 percent of the time; adding a second odd column to 7 (5-7-9) pushes that to 14.7 percent. A middle pair plus one odd column, such as 6-7-8 or 5-6-8, gives you both frequency and coverage. Avoid ending up on three outer columns unless the game forces you there.

3. Prefer doubles that reuse a runner

When a roll offers 9+9 as well as 7+11, the doubled 9 moves two steps and keeps a runner in hand, which means another bust-free roll. Two steps in one column are worth more than one step in each of two columns when one of those steps commits your last runner to a bad number.

4. Finish what you start

Steps are only banked when you stop, and a column is only yours when a marker reaches the top. A runner at step 10 of column 7 is worth nothing if you bust. When a runner reaches a top step, stop and claim it unless another column is also one step from finishing and the bust chance is tiny.

5. Count the Rule of 28

Keep a running tally as you move. A fresh runner placed on 7 counts 2 (1 doubled), one on 12 counts 12. Reaching 28 with three runners out is your cue to stop; if you are behind and your opponent is one column from winning, push past it, because a safe stop that still loses is not safe at all.

6. Watch the columns your opponent is close to claiming

Every claimed column removes a number from the game for everyone else, and losing 6, 7 or 8 raises every future bust chance you face. If the computer has a marker at step 10 of column 7, racing it there, or shifting your plan to 6 and 8, is better than ignoring it.

7. Value short columns for what they are

Column 2 takes only three steps, but a pair adding to 2 appears on 13.2 percent of rolls, so a runner there is dead weight for the rest of the turn. Take short columns when a double drops two steps at once or your marker is already partway up, rarely with a fresh runner early in a turn.

Common Mistakes

• Stopping with a runner in hand. You gave up a roll that could not bust.
• Placing the third runner on 2, 3, 11 or 12 to gain a single step. Compare the bust chance before and after; 6-7-8 to 2-6-7 is a jump from 8 percent to around 20.
• Forgetting that both totals must be moved when they can be. A pairing of 7 and 12 with a spare runner forces the runner onto 12, whether you want it there or not.
• Rolling with a runner on a top step. The column is not claimed until you stop.
• Treating a bust as bad luck. With runners on 3-5-7 you bust more than one roll in five; that is a choice, not misfortune.

Variants and House Rules

• Blocked columns. In some editions, markers of other players in a claimed column are physically removed; in others they stay but cannot move. The result is identical: the column is dead.
• Two columns to win. A shorter game for four players or for teaching.
• Solitaire Can’t Stop. Play alone and count the turns needed to claim three columns; under ten is excellent.
• Can’t Stop Express. Sackson’s roll-and-write variant, in which players tally pair totals on a sheet instead of racing runners.

If you like this style of decision, Farkle applies it to six dice and a scoring table, Zombie Dice to custom dice and shotgun blasts, and Yahtzee to a scorecard with three rolls per turn.

Glossary

• Runner: One of the three white, shared markers that move during a turn.
• Marker: Your own colored piece that records progress when you stop.
• Bust: A roll with no pairing that can move a runner; the turn’s progress is lost.
• Pairing: One of the three ways to divide four dice into two pairs.
• Claim: Stopping with a runner on the top step of a column, making it yours and closing it to others.
• Free runner: A runner not yet placed this turn; while you have one, you cannot bust.
• Rule of 28: Michael Keller’s stopping heuristic based on weighted column steps.
• Doubles: A pairing whose two totals are equal, moving one runner two steps.

Play Can’t Stop Online on Dice.now

The board at the top of this page is a two-player game against the computer on the standard eleven-column board: columns of 3, 5, 7, 9, 11, 13, 11, 9, 7, 5 and 3 steps, three runners per turn, four dice, and three claimed columns to win. It is a free fan re-creation built for learning and practice. It is not affiliated with or endorsed by Eagle-Gryphon Games, Franjos or the estate of Sid Sackson; the official game, with its mat, dice and wooden markers, is on the Eagle-Gryphon Games Can’t Stop page.

Press Roll 4 Dice, then choose one of the pairing chips that appear (each is labeled with its column totals; a doubled total shows as “9 ×2”). Only legal pairings are offered: if both totals can be used the chip moves both, if only one fits the runner limit you get a separate chip for each, and totals in claimed or finished columns are dropped. After moving, press Roll again or Stop to lock your runners in as markers. A roll with no legal pairing is flagged as a bust and the turn passes. Before every roll the status bar and the hint line show the exact chance the next roll busts, computed by checking all 1,296 four-dice outcomes against your current runners, and 0 percent while you still hold a free runner.

The computer plays in the open, with every roll, pairing and stop written to the game log. It chooses pairings by weighing the fraction of a column each step covers, a large bonus for reaching a top step, a preference for reusing runners it already has out, a lean toward columns where its own marker is already high and toward the middle numbers, and a penalty for columns where your marker is far advanced. It decides when to stop with the Rule of 28 exactly as described above, including the doubled value for newly placed runners and the odd, even, high and low adjustments; it never stops with fewer than three runners out unless a runner has reached a top step or stopping wins the game.

Rolls use your browser’s cryptographic random number generator. Your win-loss record is stored on your device and never sent anywhere. Three columns, three runners, one decision at a time: roll the dice.