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How to Play

Goal

Bring all 15 checkers into your home board (the bottom-right six points) and bear them off. The first player to bear off all checkers wins.

Moving

• Each die is a separate move. You may play both dice with the same checker.
• Doubles are played four times.
• You cannot land on a point held by two or more opposing checkers.
• You must play as many dice as possible. If only one die can be played, play the higher one.

Hitting

• Landing on a single opposing checker (a blot) hits it and sends it to the bar.
• A checker on the bar must re-enter in the opponent's home board before any other move.

Bearing off

• Once all your checkers are home you may bear off. A die removes a checker from the matching point.
• A die higher than your rearmost checker bears that checker off.

Scoring

• Tavla: a normal win scores 1, a win before the opponent bears off any checker (mars) scores 2.
• Backgammon: gammon scores 2, backgammon scores 3 (opponent still has a checker on the bar or in your home board). The doubling cube multiplies the result.

Doubling cube (Backgammon)

Before rolling you may offer the cube. If the opponent takes, the stakes double and they own the cube; if they drop, they lose the game at the current value. The game after a player reaches one point from the match length is played without the cube (Crawford rule).

Provably fair dice

At the start of every game you see the hash of a secret seed; at the end the seed is revealed. You can verify yourself that every roll was fixed in advance and never altered.

Controls

On your turn, tap the dice in the middle of the board. Tap a glowing checker then its target, or drag the checker. Undo with “Undo”. Keyboard: arrow keys, Enter, Escape.

Back

Fair dice

The dice are fixed and sealed at the start of every game. Until the game ends you only see the seal's fingerprint (a hash); when it ends the seal is opened and your browser recomputes every roll. No die can be changed during the game.

The computer does not know future dice: rolls are not chosen to fit a move, moves are chosen to fit the roll. Hard level only calculates better; its dice are no better than yours.

Nothing dice-related is for sale: no paid tier, no coins, no "lucky dice". In online matches the same method runs on the server.

Dice rolled on this device

Details (hash, seed, formula)

At the start of every game you see the hash of a secret seed; at the end the seed is revealed. You can verify yourself that every roll was fixed in advance and never altered.

How: die(i) = first byte of HMAC-SHA256(seed, "die:" + i) mod 6, bytes ≥ 252 are skipped.