What does “provably fair” mean?
Most online casinos ask you to trust their RNG. Provably fair systems remove the trust requirement: the rules of the game are encoded in a small piece of math, the inputs are published, and anyone with a calculator can re-run the round to confirm the result.
How a round works on our site
- Before you bet, the server picks a random server seed and commits to it by publishing its SHA-256 hash. You see the hash up front; the seed itself stays hidden until after the round.
- You provide a client seed — by default a value generated in your browser, which you can edit before each round.
- A round counter (nonce) increments by one for every round you play in the active seed pair.
- The game outcome is computed as
HMAC-SHA256(serverSeed, clientSeed:nonce)and parsed into a result (number / multiplier / position depending on the game). - When you rotate seeds, the previous server seed is revealed so you can verify every round you played with it.
Verifying a round
Open the Provably Fair panel inside any game (next to the Bet button). It shows:
- The committed server-seed hash for your active seed pair.
- The current client seed (editable).
- Your current nonce.
- The revealed server seed of every previous pair.
Plug those values into any HMAC-SHA256 calculator (or our in-browser verifier when it ships) and you'll get back exactly the same byte stream the server used to compute your result.
What about the house edge?
Provably fair guarantees honesty, not zero house edge. Each game has a published RTP — the math is transparent, the rounds are verifiable, but the house still wins on average over millions of rounds. That's how casinos pay their bills.
Rotating seeds
You can rotate seeds at any moment from the same panel. The new pair gets its own committed hash; the previous server seed is revealed for verification. Rotating mid-game does not affect results that already happened — they remain provably fair under the seeds in effect at the time.