Playgridia
Backgammon
Real backgammon — with the doubling cube, match play and dice you can verify.
24 points
Rules
- The goal: bring all fifteen of your checkers home, then bear every one of them off the board.
- The opening: at the start of every game each player throws one die. The higher die starts and plays both numbers together; a tie is thrown again.
- You throw two dice and must play both; if only one of them can be played, you play the higher.
- Roll a double and you play that number four times.
- You may not land on a point holding two or more of your opponent's checkers.
- A lone checker is hit; it goes to the bar, and you may make no other move until it re-enters.
- Once every checker is home you start bearing off; if the die is higher than any occupied point, you bear off from the farthest one.
- Finish before your opponent bears off a single checker and it is a gammon (double); with a checker still on the bar or in your home board, a backgammon (triple).
- THE DOUBLING CUBE (a room setting, off by default): when it is on, on your turn and before you throw you may offer to double the stake. Your opponent takes it or gives up that game.
- The Crawford rule (only with the cube on): once either player is one point from winning the match, the cube is off for exactly one game.
How to play
- Every game begins with the opening roll: tap "Throw your die" or the dice well, and your opponent throws theirs. The higher die starts and plays both numbers together.
- After that the dice throw themselves. Tap the checker you want to move, or drag it with your finger — every point it can reach is marked, with the number of pips that move costs.
- A checker never moves on its own: you tap where it goes. To bear off, tap the checker, then your rail.
- You can play both dice with one tap: rolled 2 and 1, tap the point three away — if the point in between is open, the checker plays both.
- Until the turn is sent, ↶ takes back as many steps as you like — and, as at a real table, your opponent watches every checker you move and take back.
- When every die is played, a ring runs round the dice: tap them to end your turn, or let the ring run out. With ⚡ fast mode on the dice roll themselves, and once no checker can be hit any more it bears your checkers off for you; switch it off and the "Roll" button comes back.
- Your pip count sits beside your name: how much road each player has left to home.
The doubling cube (optional)
- It is off by default; it joins the game when the room is created with "Doubling cube: On".
- It doubles the stake of the game. Whoever takes it owns the cube, and only they can double next.
- Refuse the offer and the game ends at its current value — the gammon risk disappears with it.
- When should you double? Roughly once your chance of winning passes 68-70%; below about 25% your opponent should no longer take.
- A 1-point match has no cube: a doubled stake would already be longer than the match.
- In fast mode the dice throw themselves after a short pause — to double, tap "Double" while that window is running.
The clock
- Every turn starts with a free window — move inside it and your clock does not run at all.
- Seconds past that window come out of a reserve you keep for the whole match.
- The reserve scales with match length: ten minutes each in a 5-point match.
- Run the reserve out and you lose the match — which is why it is a MATCH bank, not a game one.
The dice, and trusting them
- At the start of every game the server publishes the hash of a secret key — from that moment the dice cannot be changed.
- Both players contribute a seed of their own; every roll comes out of the three combined.
- When the game ends the secret key is revealed and you can recompute every single roll yourself.
- The board you pick does not touch the dice: all four produce identical rolls from the same seeds.
The boards
- Classic: the tournament board. Always free, and the clearest of the set.
- Ivory Club: green baize, brass, and ivory-and-ebony checkers.
- Bazaar: mother-of-pearl and brass inlay on rosewood — the game's home for a thousand years.
- Midnight: dark slate and cold light, for playing at night.
- All four play the SAME backgammon. A theme changes the art, the sound and the music — never a rule and never a die.
Play Backgammon Online — Free, No Account Needed
Backgammon has been played on the same twenty-four points for five thousand years and nobody can claim to have solved it. This is the full game: the doubling cube, gammons and backgammons, the Crawford rule and the bear-off rules exactly as published. Nackgammon and Hypergammon openings are on the table too.
You can start without signing up. Open a table and send a friend the link, or sit down against a bot from a ladder that runs from beginner to master. The board runs in the browser on a phone or a desktop, with nothing to install.
The cube — and why the MATCH is the real game
A single game is largely the dice; a match is where skill shows. Here a table is a match to 1, 3, 5, 7 or 11 points, and points accumulate across the games inside it. The longer the match, the smaller luck's share of the result.
The cube doubles the stake and is the hardest decision in the game: double too early and your opponent simply takes, too late and you leave the points on the table. Refusing is a move as well — the game ends there at its current value. The Crawford rule locks the cube for one game at match point, so the trailing player cannot just double every hand.
Verify the dice yourself
The oldest complaint about online backgammon is that the dice are rigged. Our answer is a proof rather than a promise. Before a game begins the server publishes the hash of its secret key, which locks every roll in place before the first throw.
Both players then add a seed of their own, and each roll is computed from all three. When the game is over the secret key is revealed and you can reproduce every throw line by line. The board theme has no effect on any of it: the same seeds give the same dice on all four boards.
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