Section 1: Introduction
Backgammon is a two-player race game in which each side moves fifteen checkers around a twenty-four point board according to dice rolls, hitting and blocking the opponent, and wins by bearing every checker off first.
Competitive play is regulated internationally by the World Backgammon Federation (WBGF), which promotes the game as a mind sport and runs the official global championship. This page follows the USBGF/WBGF Tournament Rules: Ruling Guide, 2024 edition, published by the USBGF Rules and Ethics Committee, which provides the detail and interpretation behind those rules.
- The guide exists to give guidance on the intent and interpretation of the Tournament Rules and to address uncommon situations (Rule 1.1.1).
- Disputes, inquiries and rulings follow a defined process, beginning with establishing the facts (Rule 1.1.4, Rule 1.1.4.1).
- Tournament director impartiality is required when ruling (Rule 1.1.4.2).
- Circumstances not covered by the rules are addressed explicitly rather than left open (Rule 1.1.4.3).
- Players are obliged to point out rule violations (Rule 1.1.6), and penalties are defined (Rule 1.1.5).
Section 2: Components
- Dice requirements are set out in general terms and for selection and use (Rule 3.2.1, Rule 3.2.2).
- The number of dice used during play is specified (Rule 3.2.2.1), as is the mixing of dice (Rule 3.2.2.2).
- Dice must be produced through an approved randomisation device (Rule 3.2.3, Rule 3.2.3.1).
- Cups are covered as a randomisation device (Rule 3.2.3.2).
- Baffle boxes have their own construction, approval and placement requirements (Rule 3.2.3.3.2, Rule 3.2.3.3.3).
- Other dice randomisation devices are addressed separately (Rule 3.2.3.4).
- Equipment preference policies and disputes over them are defined (Rule 3.3.1, Rule 3.3.2).
- The game clock has its own purpose, construction, approval and placement rules (Rule 3.4.1, Rule 3.4.2, Rule 3.4.3).
- Defective equipment is handled by rule (Rule 3.5.4), and equipment may be changed under defined conditions (Rule 4.1.4).
Section 3: Setup
- Errors in the starting position are addressed explicitly (Rule 4.2.1).
- The opening roll is governed by rule, including when produced using a baffle box (Rule 4.1.3.2.2).
- Dice must be random (Rule 4.1.1) and handled according to rule (Rule 4.1.2).
- The doubling cube begins at a defined initial position (Rule 4.4.1).
- Game clock settings at the beginning of a match are specified (Rule 3.4.4.3), as is introducing a clock mid-match (Rule 3.4.4.4).
- Time control settings and player preferences are defined (Rule 3.4.4.1, Rule 3.4.4.2).
Section 4: Gameplay
Players alternate rolling two dice and moving checkers toward their home board. A roll of doubles is played twice. A lone checker may be hit and sent to the bar, and must re-enter before its owner may move anything else.
- What constitutes a valid roll is defined (Rule 4.1.3), including proper dice-rolling technique with a cup (Rule 4.1.3.1.1).
- Rolling the dice on the left is addressed specifically (Rule 4.1.3.1.2).
- Invalid rolls are treated differently before the dice begin to settle and once they have come to rest (Rule 4.1.3.3.1, Rule 4.1.3.3.2), with a defined handling procedure (Rule 4.1.3.3.3).
- Whether dice landing on checkers invalidates a roll is an explicit rule option (Rule 4.1.3.4).
- Move and checker-handling requirements are set out, covering both moves and the handling of checkers (Rule 4.2.2.1, Rule 4.2.2.2).
- Checker shuffling and the testing of alternative plays are permitted within limits, including offsetting moved checkers and restoring the original position between alternatives (Rule 4.2.2.3.1, Rule 4.2.2.3.2).
- Illegal moves are governed by rule (Rule 4.2.3), and invalid positions are corrected under a defined procedure (Rule 4.2.3.6).
- The end of turn differs depending on whether a game clock is in use and how many dice are in play (Rule 4.1.6.1, Rule 4.1.6.2, Rule 4.1.6.3).
- Premature actions are penalised: lifting the dice early is a "fast grab" (Rule 4.1.7.1) and rolling early is a "fast roll" (Rule 4.1.7.2).
- A premature roll that preempts a double during a close-out has its own rule (Rule 4.1.7.3).
Section 5: Scoring & Winning
A game is won by bearing off all fifteen checkers. The margin determines the value, and the doubling cube multiplies it.
The Doubling Cube
- The cube has a defined initial position, current value and current position at any point in the game (Rule 4.4.1, Rule 4.4.2, Rule 4.4.3).
- Which actions constitute accepting or rejecting the cube is specified (Rule 4.4.6).
- Ambiguous and inappropriate cube handling is addressed (Rule 4.4.7).
- Dead cubes are defined (Rule 4.4.9), as is a cube displayed or turned to an incorrect level (Rule 4.4.10).
- Automatic doubles, beavers and the Jacoby rule are covered as optional conventions (Rule 4.4.11).
- Erroneous acceptance or pass of a Crawford game double each have their own remedy (Rule 4.4.8.1, Rule 4.4.8.2).
Match Score
- Saving gammon is addressed explicitly (Rule 4.5.3).
- The match score must be recorded (Rule 4.6.1) and updated after the completion of each game (Rule 4.6.2).
- Errors in scorekeeping are handled by rule (Rule 4.6.3).
- Position and match recording are covered separately (Rule 1.8.2).
Section 6: Variants & House Rules
The rules above govern sanctioned tournament play. Several widely used conventions are optional and must be agreed or specified by the event:
- Automatic doubles, beavers and the Jacoby rule are treated as options rather than defaults (Rule 4.4.11).
- Dice on checkers: whether this invalidates a roll is an explicit rule option, not a fixed rule (Rule 4.1.3.4).
- Baffle boxes vs cups: both are permitted randomisation devices with different requirements (Rule 3.2.3.2, Rule 3.2.3.3.1).
- Chouette: the multiplayer money-game form, in which one player takes on a team of others each holding their own cube. Outside the scope of the tournament rules.
- Nackgammon and hypergammon: alternative starting positions used casually; the tournament rules address errors in the standard starting position only (Rule 4.2.1).
