Play Chicago Online

What Is Chicago?

Chicago is one of the shortest and purest dice games there is. Eleven rounds are played, numbered 2 through 12 after the eleven possible totals of two dice. In every round each player throws two dice once. If the total equals the round number the player scores a point; if not, nothing. When the round numbered 12 is finished, the player with the most points wins, and if two or three players are level they share the honors.

Nobody makes a decision in Chicago, and that is the point. Each round is a small, honest experiment in probability. In round 2 you are looking for double 1s, a 1-in-36 shot; five rounds later you need a 7, and nearly one throw in six will do. Over the eleven rounds the chances add up to exactly one expected point per player, so a game is usually decided by who happens to land their single hit, or by who manages two. It is a fine game for children learning to add two dice, for a five-minute filler between longer games, and for anyone who wants to feel the two-dice curve rather than read about it. Its relatives on Dice.now are Round the Clock, which races through 1 to 12 with the same dice, Bunco, which counts hits on a target that changes every round, and Under and Over 7, which bets on the same 36 outcomes.

A Short History of Chicago

Chicago has no inventor and no first edition. It belongs to the large family of traditional two-dice games, sometimes described as of European origin, that were passed on by play and only later written down in dice-game compendia, where it usually appears with the alternative name Rotation, after the way the target number rotates through every total from 2 to 12. The published descriptions are short and nearly identical: any number of players, two dice, eleven rounds, one throw each, score on a hit, most points wins. Some versions award the round number itself as the score rather than a single point, so that a 12 in the last round is worth twelve; others give one point per hit, which keeps the game about who gets lucky rather than when.

Why it is called Chicago is unknown. The name has been borrowed by several unrelated games: a poker variant in which the high spade in the hole takes half the pot, a Swedish card game, and, most confusingly, Twenty-Six, the ten-dice tavern game that was a genuine Chicago institution from the 1930s to the 1950s. The eleven-round dice game shares nothing with any of them except the name, and there is no evidence that it was ever a tavern or gambling game. It reads as a family or schoolroom game, and it is a very good one: the arithmetic of two dice is laid out round by round, with the hard totals at the start and end and the easy ones in the middle.

Chicago Rules

Equipment

• Two six-sided dice
• A score sheet with a row for each round from 2 to 12 and a column per player
• Two or more players; our game seats you with two computer opponents

Object

Score the most points over eleven rounds by rolling the round’s number.

How a Turn Works

1. The round number is announced. The first round is 2, the second is 3, and so on up to 12.
2. Each player throws both dice once, in turn. There is no re-roll and no holding a die.
3. Compare the total with the round number. If the two dice add up to it, the player scores one point for the round. Any other total scores nothing.
4. Record the roll and move on. When everyone has thrown, the next round begins with the next number.
5. After round 12, add up the points. Most points wins. A tie is shared; in a live game it can be broken by an extra round of 7s.

Scoring Table

Each hit scores 1 point in our version. The total of the “ways” column is 36, which is why every player expects exactly one point per game.

Worked Examples

• Round 2. You roll 1+1. Double 1s in the first round: a 1-in-36 hit and a point on the board before anyone else has rolled. Rita rolls 4+2 and Sam rolls 3+3; neither scores.
• Round 7. You roll 5+2, Rita rolls 6+1, Sam rolls 4+4. Two hits in the same round; you and Rita each score. Round 7 is the only round where more than one player scoring is at all common; the chance that at least one of three players hits a 7 is about 42%.
• Round 9. You roll 6+3. A 9, a 4-in-36 hit. Notice that 3+6 would also have counted; the order of the dice never matters, only the sum.
• Round 12. You are level with Sam at 1 point each and roll 6+6. Double 6s in the last round, a 2.8% shot, and the game is yours.
• A full game: you score in rounds 5 and 8, Rita scores in round 7, Sam never scores. Final points 2, 1, 0. Two points wins most games; a player finishing with zero, as Sam did, is the single most common result at about 35%.
• Nobody scores anything. It happens: all three players finishing on zero has about a 4% chance. The game is a three-way tie, or is settled with a round of 7s.

The Odds Behind Chicago

The two-dice distribution

Two dice can land in 36 equally likely ways, and the number of ways to make each total forms the familiar triangle: 1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1. Those eleven numbers are the odds of the eleven rounds. The middle round, 7, is six times as easy as the first and last rounds; the four “edge” rounds (2, 3, 11 and 12) together are worth only 6 chances in 36, the same as round 7 alone.

Expected points

Adding the eleven probabilities gives 36/36, so the expected number of points per player is exactly 1. That is a neat result, and it means the average game among three players produces about three points in total, spread across a 33-roll evening.

How points are distributed

Because the rounds are independent, a player’s final score is the sum of eleven separate chances. Working through all the combinations:

More than a third of players finish scoreless, and only one in fifteen manages three or more. In a three-player game your chance of finishing as the outright leader is about 21%, of sharing the top score about 28%, and of being beaten by at least one opponent about 51%. Two points is usually enough: a player with 2 is beaten only when an opponent reaches 3 or more, which has about a 13% chance across two opponents.

The rounds that decide games

Rounds 6, 7 and 8 account for 16 of the 36 chances, nearly half of all the points scored in a typical game. Rounds 2 and 12 together account for 2 in 36. A game is far more likely to turn on the middle rounds than on the dramatic doubles at either end, even though the doubles are what everyone remembers.

Chicago Strategy

1. Accept that there is nothing to decide

Every player must throw both dice once per round, and there is no way to hold, re-roll or pass. Whatever you know about the odds, your roll in round 5 is an 11.1% chance and nothing changes it. The tips that follow are about understanding, wagering and enjoying the game, not about improving a roll.

2. Know which rounds are worth a cheer

A hit in round 7 is a 1-in-6 event; a hit in round 2 or 12 is a 1-in-36 event. Treat them differently. The middle rounds decide most games, but the edge rounds are the ones that make a game memorable.

3. Expect one point and be pleased with two

The average is exactly one point. Two is a good game and will usually win or share; three is a great game and wins outright about 87% of the time against two opponents, since each of them stays below 3 with probability 93%. Zero is the single most common result, so do not take a blank sheet as a sign of anything.

4. In a betting version, price the rounds correctly

If your group plays with a small stake per round to the player who hits, make it a pot rather than a flat payment, or scale the stake by difficulty: a hit in round 2 or 12 is worth six times a hit in round 7. Equal stakes per round favor whoever happens to hit the middle rounds, which is fine as long as everyone knows it.

5. Use the round-number scoring when you want drama

The variant that awards the round number as points (12 for a 12, 2 for a 2) makes late rounds worth far more than early ones and keeps trailing players in the game until the very last roll. The one-point version rewards consistency; the round-number version rewards a single late hit. Pick the one that suits the table.

6. Do not read patterns into the sheet

A player who has hit rounds 3 and 4 is no more likely to hit round 5. A round in which nobody scored does not make the next round “due.” The completed sheet always looks like it has a pattern; it never does.

7. Watch the odds column to learn the distribution

The chance of each round is printed beside it in our game. After a few games you will know without looking that 6 and 8 are 5-in-36 rounds and that 4 and 10 are 3-in-36, which is exactly the knowledge you need for Craps, Under and Over 7 and every other two-dice game.

Common Mistakes

• Reading the dice separately. Only the sum matters. A 4 and a 3 is a 7 in round 7, not a 4 or a 3.
• Forgetting that both orders count. 2+5 and 5+2 are different results among the 36, which is why 7 has six ways rather than three.
• Thinking the last round is the most valuable. In the one-point version a 12 is worth the same as any other hit; it is just the hardest to get.
• Expecting to score most rounds. The average is one point in eleven rounds.
• Playing the rounds out of order. The 2-to-12 sequence is the game; shuffling the targets is a variant, not a mistake, but everyone should agree first.
• Breaking ties by total pips or by who scored last. A shared win is the traditional result; if you want a winner, play one extra round of 7s.

Variants and House Rules

• Round-number scoring. A hit scores the round’s number rather than one point, so a full sheet is worth 77 and a 12 outweighs a 2 sixfold. The expected score stays modest, about 7 points per player, but the variance is much higher.
• Descending rounds. Play 12 down to 2, so the game opens on double 6s.
• Reverse rotation. Play 7 outward, alternating 6, 8, 5, 9 and so on, finishing on 2 and 12 for maximum suspense.
• Ante per round. Everyone puts a chip in a pot each round; the player who hits takes it, and the pot carries over when nobody hits. The carried-over pot after several blank rounds is what makes the edge rounds exciting.
• One die. A children’s version uses one die and rounds 1 to 6, each hit being a flat 1 in 6. It is quicker and fairer round to round, but it loses the curve that makes the two-dice game interesting.
• Elimination. Players who have not scored after round 7 drop out, and the remaining players finish the sheet. Brutal, and fast.
• Any number of players. The game scales to a whole table; each extra player adds eleven rolls.

If you like the counting, Bunco is the same idea with three dice and a target that changes every round, and Round the Clock uses the same two dice to race through 1 to 12 in order. For a two-dice game with a real decision in it, try Pig with two dice, or play Craps and see the same 36 outcomes put to work on a betting layout.

Glossary

• Round number: The target total for the round, from 2 to 12.
• Hit: A roll whose two dice add up to the round number.
• Rotation: Another name for the game, from the target rotating through every total.
• Ways: The number of the 36 two-dice combinations that make a total; 1 for a 2, 6 for a 7.
• Edge rounds: Rounds 2, 3, 11 and 12, the four hardest.
• Middle rounds: Rounds 6, 7 and 8, which produce nearly half of all points.
• Shared win: The result when two or more players tie on points.

Play Chicago Online on Dice.now

The game at the top of this page is Chicago against two computer players, Rita and Sam, over eleven rounds numbered 2 through 12. Press Roll to throw your two dice for the current round; the dice animate, and if they add up to the round number they turn green and you score a point. Rita and Sam then roll in turn, one at a time, with their dice shown in the same place, and the round table records every roll for all three players with a check mark on each hit. The status bar shows the round and its odds, everyone’s points and your win-loss record, and the roll log lists each throw.

Each hit scores one point. After the round numbered 12, the player or players with the most points win; a tie is shown as a shared win. There is no betting and nothing to buy: it is a five-minute game of pure probability with the odds of every round printed beside it. Rolls use your browser’s cryptographic random number generator, and your record is stored on your device only. New Game starts over at round 2 at any time, even in the middle of a computer roll. Roll for a 2.