Backgammon

What Is Backgammon?

Backgammon is a race game for two players, each with 15 checkers, played on a board of 24 narrow triangles called points. You move your checkers around the board by the roll of two dice, in the opposite direction to your opponent, hitting lone enemy checkers on the way. The first player to bear all 15 off the board wins, and a doubling cube lets either side raise the stakes mid-game.

Play against the computer, or play a friend on the same device, taking turns as White and Black. Our board sets up the standard starting position, rolls the dice when you tap Roll Dice, shows where a checker can go once you tap it, and keeps the doubling cube in play. Gammons and backgammons score 2 and 3 points, multiplied by the cube.

How to Set Up a Backgammon Board

Each player sets out 15 checkers the same way, counting the points from their own side: 2 on the 24-point, 5 on the 13-point, 3 on the 8-point, and 5 on the 6-point. That is 2 + 5 + 3 + 5 = 15. Your opponent does the same from their side, so in your numbering their checkers sit on your 1, 12, 17, and 19-points.

Where each stack goes

Count the points from your own side. Your home board is 1 to 6 and your outer board 7 to 12; your opponent's outer and home boards are your 13 to 18 and 19 to 24. Each point has two numbers, one per player, that add up to 25, so your 1-point is their 24-point. The 7-point is the bar point; the 13-point is the midpoint.

Step-by-step setup

1. Agree which side the home boards go on. Sit facing each other with the board between you. Both home boards go on the same side of the bar, directly facing each other. Either side is legal; tradition puts them on the side nearest the light.
2. Put 5 checkers on your 6-point. The 6-point is the point in your home board that touches the bar.
3. Put 3 checkers on your 8-point. The 8-point is in your outer board, one point past the bar point.
4. Put 5 checkers on your 13-point. The 13-point, or midpoint, is the far end of your opponent's outer board, on your left if your home board is on your right.
5. Put 2 checkers on your 24-point. The 24-point is the far corner of your opponent's home board. These two back checkers have the longest trip home.
6. Have your opponent mirror the layout. Your opponent places 2, 5, 3, and 5 checkers on their own 24, 13, 8, and 6-points, which are your 1, 12, 17, and 19-points. Every stack now faces an enemy stack of the same size.
7. Centre the doubling cube on 64. The cube starts in the middle with 64 showing, which means the game is worth 1. Each player keeps a pair of dice and a cup.

Home board on the left or the right

With your home board on your right you move anticlockwise and your opponent clockwise; flip the layout and both directions flip. Because the home boards face each other, one of the two players always has theirs on the left, so no layout gives both players their home board on the right. John Longacre, writing in 1930, traced the custom of setting the home boards nearest the light to candlelit play.

Setup mistakes to avoid

• Home boards on opposite sides. They must face each other across the same end of the board.
• Counting from the wrong corner. Your 24-point is deep in your opponent's home board, not in your own.
• Forgetting the 8-point, or putting four checkers there instead of three.
• A count other than 15. Recount each colour before the opening roll.
• The cube on one player's side. Nobody owns it at the start, so it goes in the middle.

On screen you can skip all of this: our board sets out the starting position every time you press New Game, and its cube shows the stake itself, starting at 1.

How to Play Backgammon

Bring all 15 of your checkers into your home board, then bear them off before your opponent bears off theirs. A turn is one roll of two dice, and every rule below decides which moves that roll allows.

1. Roll for the first move. Each player rolls one die. The higher number goes first and plays both numbers showing. Ties are rolled again, so the first move is never a double.
2. Move forward by the dice. Each die is a separate move toward your home board. One checker can take both numbers if the point it touches after the first number is open.
3. Play doubles four times. A roll of 4-4 gives you four moves of 4, which is 16 pips in all.
4. Land only on open points. A point with two or more enemy checkers is blocked. Anything else is open: empty, holding your own checkers, or holding one enemy checker.
5. Hit blots and enter from the bar. Landing on a lone enemy checker, a blot, sends it to the bar. A player with a checker on the bar must bring it back in through the opponent's home board before moving anything else. A roll of 1 enters on the opponent's 1-point (your 24-point) and a 6 enters on their 6-point (your 19-point).
6. Use both numbers when you can. If a legal sequence plays both dice, you must find it. If only one number can be played, play it; if either could be played but not both, play the higher. A number that cannot be played is lost.
7. Bear off once all 15 are home. A 4 removes a checker from your 4-point. If that point is empty you must move a checker down from a higher point, and if no checker sits higher, the 4 bears off from your highest point.
8. Bear off all 15 first to win. How far your opponent is from finishing decides whether you win a single game, a gammon, or a backgammon.

A checker hit during the bear-off has to come in from the bar and travel all the way round to your home board before you may take another checker off. Bearing off is also never forced while another legal move exists, so you can move a checker down inside your home board instead when that is safer.

Our board plays these rules for you. It offers only legal moves and passes your turn when no number can be played. The Bear Off button appears only once all 15 of your checkers are home. The full backgammon rules cover the edge cases, from two checkers on the bar to bearing off with a higher number.

Gammons, Backgammons, and the Doubling Cube

A win is worth 1, 2, or 3 points depending on how far behind the loser is, and the doubling cube multiplies that. Your opponent's progress at the moment your last checker comes off decides the result.

The cube has six faces, 2, 4, 8, 16, 32, and 64, and starts in the middle on 64, which stands for 1 because there is no 1 face. At the start of your turn, before you roll, you may offer to double while the cube is in the middle or on your side. Your opponent either takes, and the game goes on at twice the stake with the cube now on their side, or drops, also called passing, and concedes the stake as it stood before the double. Only the player who owns the cube can redouble, so nobody doubles twice in a row, and there is no limit on how high it goes.

On our board every game is scored on its own. There is no match score, so the Crawford rule never applies, and there is no Jacoby rule, so a gammon counts double even if the cube never moved. Beavers and automatic doubles are not used. The player who wins the opening roll cannot double before that first move, but the other player may double before their first roll. When you are offered a double, the panel states both outcomes, the new stake and what declining concedes, before you choose.

Backgammon Strategy for Beginners

Make your 5-point. It is the most valuable point on the board, which is why 3-1, played 8/5 6/5, is the best opening roll. Your 4-point and bar point come next. Points in your home board block enemy checkers and give you somewhere safe to land, and six made points in a row, a full prime, cannot be passed at all.

Computer rollouts have ranked the plays for every opening roll, and where two plays are nearly equal the note says so. There are 15 possible opening rolls, because a tied opening roll is rolled again. Notation reads from-point/to-point, so 24/13 moves a back checker from your 24-point to your 13-point.

Count the shots before you leave a blot. A lone checker up to 6 pips in front of an enemy checker can be hit by 11 to 17 of the 36 possible rolls when no points block the way, and 17 at exactly 6 pips. At 7 pips the count falls to 6, so moving a blot one step further away can cut the danger by nearly two thirds.

Know who leads the race. Your pip count is the total distance your checkers still have to travel, 167 for each side at the start. When you lead, race your checkers home and avoid contact. When you trail, keep an anchor, two or more checkers on a point in your opponent's home board, ideally their 5 or 4-point (your 20 or 21-point), and wait for a shot.

Do not bury checkers or stack them. A lone checker dropped on your 1 or 2-point early, such as 6/1 instead of 13/8, is out of play for the rest of the game. Making the 2-point with an opening 6-4 is a separate case that computer rollouts rate as sound. Five or more checkers on one point waste material that could be making new points; about four is the useful limit.

Take a double if you win at least a quarter of the time. Taking risks one more point to win three, so 25 percent is the break-even when neither side can win a gammon, and owning the cube pulls it down toward 20 to 22 percent. Gammon chances push it up. Because our board has no Jacoby rule, a strong position can play on for a gammon without ever turning the cube.

The backgammon strategy guide covers game plans, pip counting, and bearing off against contact, and the glossary defines the core terms, from blot to prime.

Backgammon Variants

Most variants change the starting position or what happens when checkers meet. Our board plays standard backgammon only; these are games to try on a physical board.

• Nackgammon, from Nack Ballard, starts 2 on the 24-point, 2 on the 23, 4 on the 13, 3 on the 8, and 4 on the 6. A second back anchor means more priming battles and fewer blitzes.
• Hypergammon gives each player three checkers, one each on the 24, 23, and 22-points. Hugh Sconyers solved it by computer in the early 1990s.
• Acey-deucey, long a favourite in the US Navy, starts with every checker off the board. A roll of 1-2 lets you play the 1 and the 2, then any double you choose, then roll again.
• Greek tavli is three games played in turn: Portes, close to standard backgammon without the cube; Plakoto, where a checker landing on a blot pins it instead of hitting it; and Fevga, where both players run the same way and nobody is ever hit.
• Turkish tavla keeps the standard setup but drops the cube, scores a gammon (mars) as 2 with no triple, and forbids hit-and-run inside your own home board.
• Long nardy, the Russian and Caucasian favourite, starts all 15 checkers on one point, sends both players the same way round, and has no hitting at all.

The backgammon variants guide compares their starting positions and contact rules side by side.

Where Backgammon Came From

The 5,000-year age often quoted for backgammon belongs to other race games. The earliest game in backgammon's family with known rules is tabula, played in the late Roman world. A poem by Agathias records a disastrous throw of 2, 5, and 6 by the Emperor Zeno around AD 480, on a board of 24 points with 15 checkers a side and three dice.

The Royal Game of Ur, from about 2600 BC, and the board from Iran's Burnt City both have 20 squares rather than 24 points, and historians have not shown that either is an ancestor. Persian tradition credits the related game of nard to Bozorgmehr, vizier to the Persian king Khosrow I, a story that historians treat as legend.

Medieval Europe called the game tables. Louis IX of France banned his court officials and subjects from playing it in 1254, and Alfonso X of Castile described more than a dozen tables games in his Libro de los juegos of 1283, one of them with backgammon's starting position. Elizabethan laws and church rules banned playing at tables in 16th-century England. The word backgammon first appears in the 1640s, most likely from "back" and the Middle English gamen, a game, and Edmond Hoyle published his treatise on it in 1743.

The doubling cube arrived in New York clubs in the 1920s, and nobody knows who invented it. Prince Alexis Obolensky ran the first international tournament on Grand Bahama in 1964, and the world championship settled in Monte Carlo in 1979. That July a program called BKG 9.8 beat the new world champion, Luigi Villa, 7-1 in a short exhibition match. In the early 1990s IBM's TD-Gammon taught itself the game by playing against itself, and its preference for splitting the back checkers changed how experts play opening rolls such as 4-1 and 5-1.

The full history of backgammon follows the game from Roman tabula to the computer era.

Frequently Asked Questions

More backgammon questions answered