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The dice and cards are fair,
and you can check it yourself

Every dice roll and every card shuffle comes from a secret we fix before the game and a number from your phone. After the match the secret is revealed, and anyone can recompute it.

How it works

Three stages, the same way for every game: dice in Ludo and tawla, cards in Baloot, Jackaroo and Hand.

Before the first roll

We fix the secret

Our secret for this match••••••••
Its fingerprint, shown to youa3f9…7c21

The fingerprint pins the secret without revealing it. We cannot change it afterwards.

During play

Every roll is computed

Our secret
+
A number from your phone7e02…c1a6
+
Roll number38
The die5

So neither we nor anyone else chooses a roll alone.

After the end

The secret is revealed

The secret, revealed9c1e…
Does its fingerprint match what you saw?
Does every roll and shuffle replay the same?

Recompute it here, or with any program of your own.

What this guarantees you

  • We cannot change a roll once the game startsThe fingerprint is published before the first roll, and any change to the secret shows.
  • We cannot choose your rollsYour phone’s number goes into every roll, and we fixed our secret before we knew it.
  • Your cards stay hidden during playThe shuffle order is revealed only after the game, so nobody sees anyone else’s cards.

For developers

hash  = SHA-256(serverSeed)
seed  = clientSeed0|clientSeed1|…
draw n = HMAC-SHA256(serverSeed, seed:n)
die   = uniform(6) + 1
deck  = Fisher-Yates, uniform(i+1)

uniform rejects the surplus bytes so there is no bias. Every match’s result page has the secret, the numbers and every roll and shuffle, so you can recompute it yourself.

Questions about verifying

If the server knows the secret, can’t it cheat?

The secret is fixed and its fingerprint shown before the first roll, before we know anything about the play. If we changed it afterwards the fingerprint would not match, and anyone could see that. And your phone’s number goes into every roll, so we cannot arrange them in advance.

Why not reveal the secret from the start?

Because whoever knows the secret can compute the coming rolls and the order of the cards before they are played. So it is revealed as soon as the match ends.

Does verifying cover the cards in Baloot and Jackaroo?

Yes. Every shuffle is computed the same way, one shuffle per deal. During play everyone’s cards are hidden; after the game you can check every deal.

Where do I find the match ID?

On the end-of-match screen under «تحقق» (Verify), and you can share the link with the people you played with.