IntroducingProvablyFair.orgCertification
The casino builds the game.
It should not be the only party checking it.
Michael Smargiassi
· ProvablyFair.org
Why we exist
You can already verify your bets at a provably fair casino. Enter your seeds, run the casino’s checker, confirm the result. So why does ProvablyFair.org exist?
Because what that verification proves is narrower than most players think.
A seed check can reproduce a result and confirm that a revealed server seed matches an earlier commitment. Those are valuable checks. But they do not, by themselves, establish that the game’s rules, payout calculations and advertised house edge are correct.
When the casino builds the game and controls the checker, it is checking its own work. Agreement between them is useful evidence of consistency. An independent audit is the part that has been missing.
01 / The structural problem
The category has a structural problem
Many crypto casinos now build their own original games. Plinko, Mines, Crash, Limbo, Dice and Keno: developed by the casino, operated by the casino and accompanied by a verifier the casino also controls.
Independent testing separates the organisation making a product from the organisation assessing its claims. That separation matters just as much when the product is a provably fair game.
Publishing an algorithm makes independent checking possible. It does not mean that checking has happened. Players still need to know whether the live game follows the published rules and whether the payouts match the advertised return.
The casino’s own verifier
ONE OPERATOR
Casino game
↓ Sent to its own checker
The house is confirming the house.
Independently certified
A SEPARATE CHECK
Casino game
↓ Public seeds + published rules
The claim is tested outside the casino.
02 / The verification gap
What that produces
The gap is practical, not theoretical. Our investigations have surfaced issues that a successful seed check does not resolve: changed payout tables, unused client seeds, broken commitments and verifiers that do not reflect the live game.
Finding those problems means going deeper: examining the specification, capturing bets and recomputing results independently. That takes time, tooling and technical expertise an individual player should not need.
ProvablyFair.org was built to do that work systematically—and make the evidence available to everyone.
01Payouts change
The checker agrees, but the advertised return no longer matches.
02Seeds do not participate
A client seed is accepted without affecting the outcome.
03Commitments break
A displayed hash is changed after the player’s input.
04Verification is disconnected
Published checker code differs from the game being played.
03 / Introducing certification
Introducing ProvablyFair.org Certification
ProvablyFair.org Certification is an independent audit framework built specifically for casino-built provably fair games.
It starts with a simple principle: an audit of a “verify it yourself” product should itself be something anyone can check.
We rebuild each game from its published specification, rather than relying on the casino’s supplied implementation. We then compare that independent rebuild with captured live results. The question is whether the game actually behaves as its stated rules say it should.
FROM PUBLISHED RULES TO INDEPENDENT EVIDENCE
Rebuild the game independently
Published specification → our implementation
01 / REPLAY
Real bets
Recompute captured outcomes.
Compare every result.
02 / DERIVE
Game mathematics
Calculate probabilities and RTP
from the rules.
03 / SIMULATE
Rounds at scale
Cross-check the model over
millions of rounds.
These checks answer different questions. Live-bet replay tests what happened in the captured games. Mathematical analysis establishes the expected return. Simulation provides a separate cross-check at scale.
The audit is runnable code. Published repositories connect our conclusions to verification tools, captured evidence and instructions for reproducing the checks.
04 / Five audit questions
What an audit answers
Every audit follows five core control areas. Each tests a different part of the fairness claim.
Can the casino change your outcome after you bet?
We examine seed commitments, reveals and nonce handling.
Is the randomness implemented correctly?
We check the RNG, its inputs and how outputs become game outcomes.
Does the live game follow its own rules?
We independently replay captured bets. Recomputable outcomes must match exactly.
Is the house edge honest?
We derive RTP from the rules and check the payout mathematics.
Does fairness hold under unusual conditions?
We test fairness-relevant inputs, game state and timing within the disclosed scope.
The framework also requires player-verification tools and reproducible audit evidence. The full methodology explains the requirements, the testing scope and how the checks apply to different games.
Read the full audit framework05 / What is live today
What is live today
Duel’s public audit shows this approach in practice. Its current record covers 11 in-house games, with 61,155 recomputable live bets reproduced exactly and 266 million simulated rounds supporting the mathematical checks.
DUEL.COM / PF-2026-DUEL
A public record behind the badge
PROVABLYFAIRCERTIFIED- In-house games
- 11
- Live bets reproduced exactly
- 61,155
- Simulated rounds
- 266M
- Live-bet replay
- 61,155 / 61,155 matched
- Fairness failures
- 0 in the audited scope
- Public repositories
- 11 game audit packages
The report separates derived RTP from simulated results and publishes game-by-game evidence. It also discloses four input-validation findings across three games, with no fairness failures recorded within the audited scope.
Players can use our independent verifier to check supported bets from revealed seeds and public inputs. Technical readers can inspect the implementation and rerun the audit code.
The certification badge links back to that public record: which games were tested, what was found and when the record was updated.
Reproduce the audit06 / For casinos
For casinos
A casino that builds its own games should be able to demonstrate that those games work as claimed. Independent certification gives that claim evidence outside the operator’s own systems.
For players, it provides a record they can inspect. For operators, it provides a public way to show the work behind their fairness claims.
Certification concerns the audited games and their fairness, RTP and payout logic. It does not certify the casino’s finances, licensing or wider platform security.
Our purpose is to make the fairness claim accountable: tested independently, supported by evidence and open to scrutiny.
For operators
Certify your casino
Independent testing. Published evidence.
A public record your players can inspect.