Backgammon rules: setup, moves and doubling

What you need

• A backgammon board: 24 long triangles called points, in four quarters of six, with a divider down the middle called the bar.
• Fifteen checkers for each player, in two colours.
• Two dice for each player, or one shared pair.
• A doubling cube, marked 2, 4, 8, 16, 32 and 64, if you play with doubling.

The board

Each player counts the points from their own side. You move your checkers from your 24-point towards your 1-point, and your opponent moves the opposite way. Your 24-point is your opponent's 1-point.

• Your home board is your points 1 to 6. This is where your checkers finish.
• Your outer board is your points 7 to 12.
• Your opponent's outer board and home board are your points 13 to 24.

The starting position

Both players set up the same way, each counted from their own side:

Seen from your side, your opponent's checkers stand mirrored: 2 on your 1-point, 5 on your 12-point, 3 on your 17-point and 5 on your 19-point. Each side needs 167 pips, the total distance of all fifteen checkers, to bear everything off.

Starting the game

Each player rolls one die. If the numbers are equal, both roll again. The player with the higher die moves first and plays the two numbers just rolled. After that, the players take turns rolling both dice.

Moving

1. 1.Roll both dice. Each die is a separate move.
2. 2.With a 5 and a 3, move one checker 5 points and another 3 points, or move one checker 5 and then 3. The same checker playing both numbers is two moves, and the point it stops on between them must be open.
3. 3.With a double, play that number four times.
4. 4.A checker may land on an empty point, on a point with your own checkers, or on a point with a single opposing checker. It may not land on a point held by two or more opposing checkers.

You must use both dice if you legally can. If you can play only one of them, you must play that one, and if either one can be played but not both, you must play the higher. If neither can be played, you lose your turn.

Two or more of your checkers on a point make it yours: your opponent cannot land there. Six such points in a row form a prime, and no checker can get past it.

Hitting and the bar

A single checker alone on a point is a blot. If your opponent lands on it, it is hit and placed on the bar in the middle of the board.

• While you have a checker on the bar, you may not move any other checker.
• A checker enters in your opponent's home board, on the point matching one of your dice: a 3 enters on your opponent's 3-point, which is your 22-point.
• It cannot enter on a point your opponent holds with two or more checkers. If neither die lets you enter, you lose the whole turn.
• Once every checker is back in, you play the rest of the roll as usual.

Bearing off

When all fifteen of your checkers are in your home board, you can start bearing them off.

• A die removes a checker from the point with that number: a 4 bears off a checker from your 4-point.
• You may instead use a die to move a checker inside your home board.
• If the point the die shows is empty and you have a checker on a higher point, you must move a checker from a higher point.
• If the die is higher than your highest occupied point, you bear off a checker from that highest point.
• If one of your checkers is hit while you are bearing off, it must enter and come all the way home before you may bear off again.

Scoring

The first player to bear off all fifteen checkers wins. What the win is worth depends on how far the loser got:

The points are multiplied by the value of the doubling cube.

The doubling cube

The cube raises the stake during the game. It starts in the middle at 1, usually with the 64 facing up.

1. 1.At the start of your turn, before you roll, you may offer to double.
2. 2.Your opponent either takes or drops.
3. 3.Take: the stake doubles, and your opponent now owns the cube. Only the owner may double next, so the next double would be to 4, and it would hand the cube back to you.
4. 4.Drop: your opponent gives up the game at once and loses the stake as it was before the double.

A useful rule of thumb: take when you still win at least one game in four. Dropping costs one stake; taking and losing costs two, while taking and winning gains two, so the break-even point is 25 percent, before gammons are taken into account. Offer a double when you are clearly ahead but the game is not yet so lopsided that your opponent should drop.

Match play and money play

In a match you play to an agreed number of points, such as 5 or 7. Each game adds its points to the winner's score, and the first player to reach the target wins the match.

The Crawford rule belongs to match play. When a player first reaches match point, one point short of the target, the next game is played without the cube. After that one game, the cube returns. Without the rule, the player who is behind could double in every game for free, since they have nothing more to lose.

In money play, every game is settled on its own for an agreed stake per point. Money games often add the Jacoby rule, under which gammons and backgammons count only if the cube has been turned. Some tables also play automatic doubles, where a tied opening roll doubles the cube. Agree on these before you start.

Tips for playing well

• Make points, especially in front of your opponent's back checkers. A prime traps them.
• Do not leave blots you can avoid. A blot six pips or fewer away is hit by 11 to 17 of the 36 possible rolls when nothing blocks the way; at seven pips or more, by no more than 6.
• Keep an anchor, two checkers on a point in your opponent's home board, until you are clearly ahead. It gives a hit checker somewhere to land.
• Count the pips. When you are ahead in the race, run for home; when you are behind, stay in contact and wait for a shot.
• Hitting is not always right. Making a strong point can be worth more than sending one checker back.

Playing in EU Studio's Backgammon

EU Studio's Backgammon for iPhone and iPad plays the rules on this page: the opening roll of one die each, the rule that you must play both dice or the higher one, the bar, bearing off, gammons and backgammons.

• Single game, or a match to 3, 5, 7 or 11 points.
• The doubling cube is a switch, off unless you turn it on. With the cube off, the stake never rises, but a gammon still counts 2 and a backgammon 3. The cube goes up to 64. There are no beavers, no Jacoby rule and no automatic doubles.
• The Crawford rule is on by default in matches and can be switched off.
• Five computer opponents: Beginner, Easy, Medium, Hard and Expert. Hard and Expert look at your possible replies before they move. Every level except Beginner uses the cube; Beginner never doubles and always takes. None of them gets better dice.
• Two players can share one phone or tablet, and the board turns to face whoever is on turn.
• Eight short lessons cover the rules, the cube, the Crawford rule and basic strategy. Move hints can ring the checkers that can move, or also the points they can reach, or be switched off, and you can take back a move as long as the turn still has dice left to play.