Backgammon is a two-player game in which each player has fifteen checkers that move between twenty-four triangular points using two dice. The objective of the game is to be the first player to bear off, which means moving all fifteen checkers off the board.
Backgammon involves a combination of strategy and luck (from rolling the dice). While the dice can determine the outcome of a single game, skilled players will achieve better results over a series of games.
The pieces used to play backgammon may be called checkers, draughts, stones, men, counters, pawns, discs, pips, chips, or nips.
The goal is for each player to bear off all their checkers before their opponent can do the same. As the playing time for each game is relatively short, it is often played in matches where victory is awarded to the first player to reach a certain number of points.
Each side of the board has a row of twelve long triangular points, called the points. The points form a continuous track in the shape of a horse's shoe and are numbered from 1 to 24. Each player starts with fifteen checkers, two on point 24, three on point 8, and five on each of their points 13 and 6. The two players move their checkers in opposite directions, from point 24 to point 1.
Points 1 to 6 are called the home board or inner board, and points 7 to 12 are called the outer board. Point 7 is called the bar point, and point 13 is the midpoint.
To start the game, each player rolls the dice once, and the player with the higher roll moves first using both numbers shown on the two dice. If a player rolls doubles, i.e., the same number on both dice, the player must play each number twice. The players then take turns rolling both dice in each turn.
After rolling the dice, the player must, if possible, move their checkers according to the numbers shown on each die. For example, if a player rolls a 6 and a 3 (referred to as "6-3"), they must move one checker six points forward and another checker, or the same checker, three points forward. The same checker can be moved twice, as long as the two moves are separate and legal: six and then three, or three and then six.
If a player rolls doubles, they must play each number on the dice twice. For example, rolling 5-5 allows the player to make four moves, each moving five points. On any roll, a player must use both numbers on the dice if it is entirely possible. If one or both numbers cannot be legally moved, the player forfeits that portion of the roll, and their turn ends. If a move can be made with either die but not both, the higher die must be used. If one die cannot be moved, but such a move is possible using the other die, the move with the higher die is compulsory.
During the movement, a player can land their checker on any point that is not occupied or held by one or more of their opponent's checkers. A checker can also land on a point occupied by only one opposing checker. In this case, the opponent's checker is "hit" and placed on the bar dividing the two halves of the playing surface. A checker may never land on a point occupied by two or more opposing checkers; thus, no point is ever occupied by checkers from both players at the same time. There is no limit to the number of checkers that can occupy a point at any time.
Checkers on the bar must re-enter the game through the opponent's home board before any other move can be made. Rolling a 1 allows a player to enter their checker on point 24 (the opponent's point 1), rolling a 2 brings the checker to point 23 (the opponent's point 2), and so on, until rolling a 6 allows the checker to enter point 19 (the opponent's point 6). A new checker may not enter a point occupied by two or more opposing checkers.
New checkers can be placed on vacant points or on points occupied by only one opposing checker; in the latter case, the opponent's checker is hit and placed on the bar. Multiple checkers can be waiting to re-enter on the bar at the same time. The player cannot move any other checkers until all their waiting checkers on the bar have re-entered the board. If a player has checkers waiting on the bar, but the roll does not allow any of the waiting checkers to enter the board, the player's turn ends. If the opponent's home board is entirely "closed" (meaning all six points are occupied by two or more opposing checkers), then the player will be unable to bear off any checkers and must wait until at least one point becomes open (held by one or not held by any checkers) due to the opponent moving their checkers.
You have just learned about backgammon. To play this game, you can use the JustGammon game created by Emanuel Boboiu (Manu) and translated into Vietnamese by Dao Duc Trung in ddt.one.