Server seed
Duel generates a random string on its side. You receive the hex-encoded SHA-256 hash of that seed before placing bets - proof Duel will not change its mind after seeing your wager.
Cryptographic Fairness
SHA-256 · Commit-Reveal
Duel Casino Provably Fair Verify Every House Game Outcome
All house games at Duel are provably fair. Before you bet, Duel commits to a hashed server seed. After the round, you reveal the seed and prove the outcome was random, unpredictable, and untouched - including by the casino itself.
SHA-256Server seed hash
3 inputsSeed + seed + nonce
11+Originals covered
Verified
Originals
100%
Transparent
Definition
What Is Provably Fair?
Provably fair is a cryptographic standard used by crypto-native casinos so players can audit outcomes without trusting a black box. At Duel, every house game - the in-house Originals like Dice, Crash, Plinko, Mines, Beef, Keno, Castle Roulette, Video Poker, Groomer's Van, and Rock Paper Scissors - runs on this model.
The core promise: users can verify that every bet placed had a truly random and unpredictable outcome. Duel cannot retroactively change results because the server seed is committed upfront via a one-way hash. You supply your own client seed, so the final number is not controlled by the house alone.
Third-party slots and live tables from Evolution or Pragmatic Play rely on provider RNG certification instead. Provably fair verification on Duel applies to Originals and other house-built games listed on duel.com/fairness.
Mechanics
How Duel Provably Fair Works
Before each round, three values are combined. Duel publishes the hash of its server seed before you bet - a commit-reveal scheme that prevents post-hoc manipulation.
Client seed
You provide (or rotate) your own random string. Because your seed is part of the mix, players have direct influence on the outcome - the casino cannot pick a result in isolation.
Nonce
A counter that increments with each bet in the current seed pair. One server/client seed combination can power thousands of rounds without repeating entropy.
Fair result generation
Fair result = Server seed + Client seed + Nonce
Duel maps the combined entropy into game-specific outcomes (Crash multiplier, Dice roll, Plinko path, etc.). The exact mapping differs per title but always derives from the same three inputs.
Verification
How to Verify Your Bets
After the game round, Duel reveals the unhashed server seed. You can confirm three things independently.
Hash matches commitment
SHA-256(server seed) equals the hash Duel showed before the bet. If it differs, the round was not fair.
Seeds reproduce the result
Re-run Duel's published algorithm with server seed, your client seed, and nonce. The output must match exactly what you played.
No one could interfere
Because the hash was public first, neither Duel nor a third party could alter the server seed after seeing your bet size or timing.
Try SHA-256 commit (illustrative)
Enter any server seed text to see its hex hash - the same primitive Duel uses before revealing the seed.
SHA-256 hash (hex)
Use Duel's built-in Verify tool for real bet history - this demo only shows how hashing works.
Coverage
Which Duel Games Are Provably Fair?
House Originals ship with open verification. Many run at zero house edge on top of provably fair seeds.
Dice
Crash
Plinko
Mines
Beef
Keno
Castle Roulette
Video Poker
Groomer's Van
Rock Paper Scissors
Live Blackjack
Licensed third-party slots and Evolution live tables use provider RNG audits - not client/server seeds. For full Originals breakdown see our games guide.
FAQ
Provably Fair Questions
No. Provably fair proves the outcome was generated honestly - not that the odds favor the player. On 100% RTP Originals the edge is zero, but variance still swings hard. On edge modes, the posted RTP still applies.
Yes. Duel lets you rotate client seeds so you control part of the entropy mix. Changing seeds starts a fresh nonce counter for the new pair.
Open duel.com/fairness for the official explainer and Verify button. Your bet history inside Duel also exposes seed data after each Originals round.
An Anjouan license sets operator standards. Provably fair goes further on Originals: any player can math-check individual outcomes without trusting a lab report alone.
Sports markets settle on real-world results and book margins - not seed pairs. Provably fair covers Duel's in-house casino games as described on their fairness page.
Source: duel.com/fairness. Related: Zero Edge · Full FAQ
Ready to verify your own rounds?
Play Duel Originals, then check the revealed server seed against the pre-bet hash.
18+ · Gamble responsibly · Independent review site