Safety
Provably fair explained
· 5 min read
How server seed, client seed and nonce actually prove a bet, and when a “fair” badge is just a hash on a help page.
Provably fair is a way to check that a game result was locked in before you bet, not a promise that the house edge is kind. If you cannot verify a round yourself, the badge is marketing. If you can, you still need to read the edge: a fair 1% house game is still a 1% house game.
The three numbers
- Server seed: the casino commits to a hash of this before you play, then reveals it later.
- Client seed: you set this, or the site sets one you can change. It stops the operator picking a seed after seeing your bet.
- Nonce: a counter that increments each bet so the same seeds produce a new result.
After a round you combine those inputs with a published algorithm (often HMAC-SHA256) and get the roll, card or crash point. If it does not match what the client showed, the game cheated or the docs are wrong. Either way, leave.
What it does not cover
Slots from third-party studios are almost never provably fair; they run on the supplier’s RNG and a certified RTP. A casino can mix originals you can verify with a Pragmatic lobby you cannot. That is fine if they do not slap a “provably fair” ribbon on the whole site. We only mark a brand that way when the originals you can actually audit are a real part of the product, not a dice widget in the footer.
How to check once
Play a tiny original, copy the seeds, run the official verifier or a known open-source one, and confirm the result. If the casino has no verifier, no seed reveal, or a “coming soon” fairness page, treat it as an ordinary RNG shop and score it on licence and payouts instead.
See also: casino rankings · bonus terms
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