Backgammon Position Editor & Converter

Setting up a backgammon position

The board at the top of this page opens on the starting position, ready to edit. To start from a position you already have, paste its ID anywhere on the page or open its .xgp file from the bar above the board. Editing works like eXtreme Gammon's setup mode, so a whole position takes a few seconds:

• Checkers: left-click a point for the bottom player, right-click for the top player. Where you click sets the count: the second checker's spot for two, the top of the point for five. Click the fifth checker again to add more.
• Several points at once: hold the button and drag up or down to adjust a point, or across points to fill them all to the same height.
• Empty a point: click just below it, on its number. On a touchscreen, Tap adds chooses which player you place.
• Cube: left-click moves it one step toward the bottom player (centered, then 2, 4, 8…), right-click toward the top player.
• Dice: set Position to checker play, then left-click a die to raise it or right-click to lower it.
• Turn, score, and rules: Change Player gives the other side the roll. Choose money or match, then set the match length, both scores, Crawford, Jacoby, and beavers.
• Keyboard: over a point, 0–9 set the count and +/− add or remove a checker. Del clears the board, Ins sets up the opening position, Ctrl+Z undoes, and Ctrl+Y redoes.

The XGID, GNUID, and OGID update as you edit, ready to paste into eXtreme Gammon, GNU Backgammon, or OpenGammon, and the page address holds the current position for sharing. Download the board as a PNG to use it as a diagram in an article, a forum post, or a flashcard.

Backgammon position IDs explained

A position ID is a short string that describes a whole backgammon position: the checkers, cube, dice, score, and match length. Paste one into analysis software, a forum post, or a flashcard and anyone can load the exact position. The three common formats don't read each other, so this tool reads all three, detects which one you pasted, and converts between them.

XGID (eXtreme Gammon)

An XGID is XGID= followed by ten fields separated by colons. The checker string is always written from the bottom player's side of the board, whoever is on roll.

GNUID (GNU Backgammon)

A GNU Backgammon ID has two parts separated by a colon. The 14-character Position ID holds only the checkers: an 80-bit key that lists, for each player, a 1 for every checker and a 0 after each point, from their ace point round to the 24-point and then the bar. The player not on roll comes first. The key is packed into 10 bytes and written in Base64, and the starting position is always 4HPwATDgc/ABMA.

The 12-character Match ID holds everything else: the cube value and owner, the player on roll, the Crawford flag, the game state, any double or resignation on offer, the dice, the match length (0 for money), and both scores.

OGID (OpenGammon)

An OGID lists every checker as one character: its point number in base 26 (0–9, then a–p), on one numbering for the whole board. White's bar is 0, Black's bar is p (25), and White moves from point 1 toward 24.

After White's and Black's checkers come the cube, the dice, a color, the game state, White's score, Black's score, the match length (with a C suffix in the Crawford game), and a move number. The cube is three characters: the owner (N for centered, W, or B), its value as a power of 2, and its state (N, or O, T, P for offered, taken, passed), so N0N is a centered cube on 1. The color is the player who acted last, so the player to act is the other one.

One position, three IDs

The opening position, with the bottom player to play 3-1 in a money game and the cube centered:

• XGID: XGID=-b----E-C---eE---c-e----B-:0:0:1:31:0:0:0:0:8
• GNUID: 4HPwATDgc/ABMA:cIkFAAAAAAAE
• OGID: 11ccccchhhjjjjj:66666888dddddoo:N0N:31:B:R:0:0:0:0

In the XGID, the first character is the top player's bar, so the seventh character, E, is the bottom player's five checkers on their 6-point, and the second, b, is the top player's two back checkers on the bottom player's ace point. Both players have 167 pips.

Pasting a position into GNU Backgammon or eXtreme Gammon

• GNU Backgammon: copy the ID and choose Edit → Paste ID (Ctrl+V). It accepts a GNUID or an XGID. To copy the current position, choose Edit → Copy ID to Clipboard → GNUbg ID.
• eXtreme Gammon: copy the whole XGID, including XGID=, and choose File → Import → Position from Clipboard (Ctrl+V). It accepts a GNUID as well. To copy the current position, choose File → Export → XGID to Clipboard (Shift+Ctrl+C).

Frequently asked questions