backgammon – the rules

Below is the hardest part of the backgammon rules – at least to me. The starting position:

Backgammon is one of those games you can learn within a couple of minutes but need a lifetime to master. But no matter how good – or bad - you are it is a very addictive game.

Each player has 15 checkers and two dice. The object is to run around the board with all checkers and “bear off” – move them off the board. The player who first removes all his stones wins.
After the board is set up each player rolls one dice. The higher roll starts the game – roll again after a draw. This first roll is also used for the first move. The starting player uses his roll and his opponent roll to move his checkers – later each player rolls both of his dice.

The numbers on both dice can be split to move two checkers or the whole roll can be used on one checker - to use the combined roll two moves using the different numbers must be possible. It is just like making two moves with the same checker. In backgammon like chess each player has to move – even if he does not like to. He has to use his whole roll if there is a legal move to do so.
Throwing the same number with both dice is called a double. Allowing to move this number not only twice but four times.

The red stones – in the above example – run from the lower right to the upper right – their home board. The black stones move in the opposite direction to their home board on the lower right.

A single checker – also called blot – can be hit by the enemy by moving to the same field. When a stone is hit it returns to the bar in the middle of the board. If a player has a checker on the bar his first play after rolling the dice must be to return the checker into the game – according to his dice he has to enter into the enemies home board (black onto the fields 1-6 and red onto the fields 19-24 [see picture above]). If he can not legally enter the checker back into the game his move is forfeit and his turn is over. After entering the board he can use the rest of his roll how he wants to.

As soon as a field is occupied by two or more checkers – called a point – the opposite player can not move to this field. It is blocked. Several points in a row are a prime. As soon as a player build a 6 point prime or full prime – 6 points in a row – the other player can not cross this barrier because the highest number on a dice is the 6. So there is no legal move to jump over these points – until the other player has to move his checkers again. If a player has build a full prime in his home board – a closed board - and the other player has a checker on the bar he does not even have to roll a dice because he will not be able to make a legal move.

As soon as a player has all his checkers inside his home board he can start to bear off. If his numbers on the dice are higher then any legal move on the board he can use it to bear off the checkers most far away.

Example:
Red has two checkers on the 5-point and one each on the 3-point and 2-point. He rolls 6 and 3. He can use the 3 to bear off the checker on the 3-point and the 6 to remove his checker currently on the 5-point.

The player bearing off all of his checkers wins. If his opponent did get at least one checker of the board himself it is called a single gammon – worth one point. If that is not the case he wins a gammon or double game – worth two points. It is called a backgammon or triple game – worth 3 points; surprise – if your opponent has still a checker on the bar or your home board.

Now get GNU backgammon and start a game...