Provable fairness, plain English
Every round on a Duel original is generated from a seed pair you can verify offline. The casino cannot know the result before you do, and you can prove the result was not changed after the fact.
How a round is built
Three inputs go into every result: a server seed (committed and hashed before the round), a client seed (you choose it), and a nonce (an incrementing counter). After the round, the unhashed server seed is revealed so you can recombine the inputs and reproduce the outcome bit-for-bit.
Verifying a round in 60 seconds
From the in-game settings, copy the seed pair and nonce of any past round. Drop them into any HMAC-SHA-256 calculator (a one-line Python script or an online tool) and recompute the digest. The first bytes of the digest map to the game outcome — match the casino's published result and you have just verified the round yourself.
Why and when to rotate seeds
Rotating your client seed invalidates all future predictions a third party could try to make. After a long session — or any time you change device — open settings and rotate. The previous server seed becomes immediately verifiable; the new one is committed before your next round.
Provable fairness FAQ
Can the casino still rig outcomes?
No — not on originals. The server seed is hashed and published before the round; once the round resolves, the unhashed seed is revealed. If the casino swapped the seed mid-round, the hash would not match and the round would be void by protocol.
Are slots from third-party providers also provably fair?
Slots use certified RNGs audited by independent labs (eCOGRA, GLI, iTech Labs) but they are not provably fair in the cryptographic sense — you trust the audit, you cannot reproduce a single spin. Provable fairness is currently exclusive to in-house originals.
What happens if my verification does not match?
Open a support ticket with the round ID and the recomputed digest. If the casino's published result does not match the math, the round is void and the wager is fully refunded. This has not happened in production, but the policy is unconditional.
Does provable fairness improve my odds?
No — it guarantees the math you signed up for. The published RTP and house edge are the actual long-run returns; provable fairness just removes the doubt that the casino is silently running them lower.