How to play Backgammon

Backgammon belongs to one of the oldest families of board games still played. Two players race fifteen checkers each, in opposite directions, around a board of 24 narrow triangles called points. The first to bring all fifteen home and then off the board wins. Along the way you can hit a lone enemy checker and send it back to the start, so the race is never just a race.

The dice decide your numbers, but you decide how to use them, and almost every roll can be played several ways. Over many games a strong player wins far more often, because they keep their checkers safe, build walls that are hard to pass, and know when to attack and when to run for home. One lucky roll can win a game; good decisions win the series.

How to play on skill.games

You play the light checkers and always move first. The computer plays the dark checkers.

• Roll: when it is your turn, tap anywhere on the board to roll both dice.
• Move: checkers that can move are ringed in green. Tap one, then tap a highlighted green point to send it there. You can also drag a checker straight to its destination.
• Using both dice at once: a point that needs both dice lights up when every stop on the way is legal, and one tap plays the whole move.
• Bearing off: once all your checkers are home, your tray glows. Tap a checker, then the tray, to take it off.
• Can't move: with no legal move, the game shows "No moves" and passes the turn.

Before each game the settings popup lets you choose Easy, Normal or Hard. The menu button in the top-left corner pauses the game. An unfinished game is saved at the start of each turn, so you can continue it next time.

The results screen shows the checkers each side bore off, turns, doubles and hits, plus your record at that level: wins, losses, win rate and streaks.

Rules

Setup. Each side has fifteen checkers. Yours start with two on the deepest point of the computer's home (top right), five at the left end of the top row, three in the bottom-left quarter and five in your home, the bottom-right quarter. The computer's checkers mirror yours and travel the opposite way, towards its home at the top right.

A turn.

1. Roll two dice.
2. Move one checker by the number on one die and a checker (the same one or another) by the number on the other. Each die is a separate move.
3. A double counts twice: a roll of 4-4 gives you four moves of 4.

Where you may land. A checker may land on an empty point, a point holding your own checkers, or a point holding exactly one enemy checker. A point with two or more enemy checkers is closed to you.

Using the dice. You must use as many dice as the position allows. If you can play either die but not both, you must play the higher one. If you cannot move at all, your turn passes.

Hitting. A single checker alone on a point is called a blot. Landing on an enemy blot hits it: that checker is put on the bar in the middle of the board and must start its journey again.

The bar. A side with a checker on the bar must bring it back in before moving anything else. It enters in the opponent's home quarter, on the point matching a die. If no matching point is open, the checker stays on the bar and the turn passes.

Bearing off. When all fifteen of your checkers are in your home quarter, you may start taking them off. A die removes a checker from the point that number matches. If you roll higher than your farthest-back checker needs, you may bear that checker off with it. You may also use a roll to move a checker forward inside your home quarter instead. If one of your checkers is hit while you are bearing off, it must come all the way home before you can continue.

Winning. The first side to bear off all fifteen checkers wins. There is no doubling cube and no extra scoring for bigger wins: each game is simply won or lost.

Strategy tips

• Make points, not blots. Two checkers together own a point and cannot be hit.
• Count the shots. Before leaving a blot, think how many rolls would hit it. A blot within six points of an enemy checker is far easier to hit than one farther away.
• Build a wall. Several points in a row in front of the computer's back checkers make it very hard for them to escape. The fifth point of your home, counted from the edge, and the point just outside your home (the bar point) are especially valuable.
• Free your back checkers. The two checkers deep in the computer's home can get trapped behind a wall. Bring them out early.
• Hit when it gains you time. Hitting a checker that has travelled far costs the computer a lot of ground; hitting one barely on its way gains little.
• Race when you are ahead. Once the armies have passed each other and you have less distance to go, stop fighting and run home.
• Bear off safely. While enemy checkers remain on the bar or in your home, avoid leaving blots, even if it means bearing off fewer checkers.

Difficulty levels

• Easy: the computer picks a legal way to play its dice at random.
• Normal: the computer weighs how far it is ahead in the race, values hitting your checkers and making points, and dislikes leaving its checkers alone.
• Hard: everything Normal does, plus it weighs how likely each of its lone checkers is to be hit, values long walls of points much more highly, and fights hardest for those same key points in its own home.