Backgammon Rules

A quick reference for how PaperGames plays backgammon - useful if you're rusty, or learning.

The basic idea

Checkers and the board: Each player has 15 checkers on a 24-point board. Black moves from point 1 toward point 24, White from point 24 toward point 1 - each racing all their checkers into their own home board and then off it.
Dice: Two dice are rolled each turn, giving two moves of those numbers; rolling doubles gives four moves of that number instead. Every die that can legally be played must be played.
Blocking and hitting: A point held by two or more of an opponent's checkers is blocked. A point held by exactly one (a "blot") can be landed on, sending it to the bar - it must re-enter through the opponent's home board before that player can make any other move.

Bearing off: Once all 15 of your checkers are in your home board, you may start bearing them off: a roll matching a checker's point removes it, and a roll higher than any occupied point may remove the furthest checker instead.
Winning: The first player to bear off all 15 checkers wins.
The doubling cube: Before rolling, a player who holds (or shares) the cube may offer to double the stakes. The opponent must accept, taking control of the cube and doubling how much the game is worth, or decline and immediately lose the game at its current value. A gammon (opponent bears off nothing) counts double, and a backgammon (opponent still has a checker in the winner's home board or on the bar) counts triple - both multiplied by the cube on top.
Resignation: A player can resign at any time, ending the game immediately in the opponent's favor.