Provably Fair

Server seed, client seed, nonce — and why a crash round cannot be rigged after your bet is placed.

The problem provably fair solves

In a land-based casino you can watch the wheel spin. Online you cannot — you see an animation, and the animation is drawn by the operator. Provably fair cryptography replaces trust with arithmetic: the result of the round is committed before you bet and revealed afterwards, so any player can check that nothing moved in between.

The three inputs

Server seed. A random string generated by the game server. You never see it while it is active — you only see its SHA-256 hash, published before the first round.

Client seed. A string that belongs to you. Most games generate one automatically and let you replace it with anything you like. Changing it is what stops the operator from tailoring the sequence to you.

Nonce. A counter that increments with every round played on the current seed pair, so identical seeds never produce identical rounds.

Verifying a round, step by step

Before playing, copy the hashed server seed shown in the fairness settings.
Set your own client seed. Anything works — a word, a date, a random string.
Play. The nonce increases with each round; note the round you want to check.
Rotate the seed. The old server seed is now revealed in plain text.
Hash it. Run SHA-256 on the revealed server seed and compare it with the hash you copied in step one. If they match, the seed was not swapped.
Recalculate the crash point. Combine server seed, client seed and nonce with HMAC-SHA256, convert the leading hex characters into a number, and apply the game’s published formula. Third-party verifiers do this in a browser tab.

If the recalculated multiplier equals the one you saw, that round was honest — proven, not promised.

What the check does not tell you

Verification proves that the operator followed its own algorithm. It says nothing about payout speed, withdrawal limits, licensing or support quality. Read the licence details and terms separately; a provably fair game inside an unlicensed casino is still a bad place to keep a balance.

Quick sanity checklist

The hashed server seed is visible before you bet, not after.
You can edit the client seed yourself.
Rotating the seed reveals the previous server seed in full.
The verification formula is published, not described vaguely.
An independent verifier reproduces the same crash point from those inputs.

Frequently asked questions

Can a casino change the crash point after I bet?

No. The server seed is committed as a hash before the round starts. Changing the outcome afterwards would break the hash, and anyone re-running the verification would see it immediately.

What does changing my client seed actually do?

It makes you a co-author of every result. Since the crash point depends on both seeds, a casino that does not know your client seed in advance cannot pre-compute a losing sequence for you.

Does provably fair mean the game has no house edge?

No. Fairness and profitability are different things. The house edge is built into the distribution of crash points — typically 1–4% — and provably fair verification only proves the published distribution was followed honestly.

How often should I rotate my seed?

Rotating after any longer session is enough. The rotation reveals the previous server seed, which is what lets you verify all the rounds played under it.

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