Provably Fair Games Explained: How to Check Every Round Yourself

15 October 2026 - 5 min read

"Provably fair" means you do not have to trust us that a round was fair - you can check it. Every Tiltyard house game works this way: Plinko, Crash, Dice, Mines, Blackjack, Roulette and the rest. Here is how it works, in plain words.

The idea in one paragraph

Before you play, we lock in a secret number - the server seed - and show you its fingerprint (a SHA-256 hash). You add your own client seed, which you can change whenever you like. Every round also has a nonce, a counter that goes up by one each time. The result of a round is worked out from those three together. Because the fingerprint was shown first, we cannot swap the server seed afterwards; because you chose the client seed, we could not have picked results in advance.

Step by step

Before the round: you see the hash of the server seed in use. The seed itself stays secret, so nobody - you included - can work out results ahead.
The round: the server combines the server seed, your client seed and the nonce with HMAC-SHA256 and turns the output into the numbers the game needs: a dice roll, the mine positions, the cards.
After: when you change seeds, the old server seed is revealed. Now you can check that it matches the hash you were shown, and replay every round you played with it.

How to check a round on Tiltyard

Open any house game and press the Fair button beside Rules.
My seeds shows your client seed, the hash of the server seed in use and the nonce. Press Change seeds to retire the pair - the old server seed is revealed.
In History, press Verify on any round played with a retired seed.
The Verifier recomputes the round in your own browser, with the game's own code, and tells you two things: whether the server seed matches the hash shown before the round, and whether the result is the round as it was played.

The check asks our server nothing - it runs entirely on your device.

What about Crash and Double?

Crash and Double are one shared round for every player, so they use one seed per round instead of your personal pair. The round's hash is shown before betting closes and the seed is revealed when the round ends - check it under This round and in History.

And the slots?

Slot rounds are decided on our server by a random number generator, never in your browser, so a game on your screen cannot be tampered with. Each slot shows its return to player (RTP) under the game, measured over hundreds of millions to billions of simulated rounds.

Why it matters

Provably fair turns "trust us" into "check us". Every house game on Tiltyard returns up to 99% of stakes over time, and every round can be checked by you, at any time, for free.