How it works in outline
Before a round, the server commits to a secret value by publishing its hash (a one-way fingerprint). You or the game add a client seed. The round's result is computed from the server seed, the client seed and a counter. After the round, the server reveals its seed; you can hash it and compare with the fingerprint shown before, then recompute the result. If they match, the server could not have changed the outcome after seeing your bet.
A round, step by step
- The commitmentBefore you bet, the server shows a hash of its secret seed. Think of it as a sealed envelope: you cannot read it, but nobody can swap its contents later without the seal breaking.
- Your inputA client seed, set by you or generated by the game, is mixed in. This is why changing it before a session matters: the server cannot have prepared a result for a seed it has not seen.
- The betEach bet uses the two seeds plus a counter, often called the nonce, which increases by one every round. The same pair of seeds with a new counter gives a new result.
- The revealAfter you rotate the seed, the server shows the old secret. Hashing it should reproduce the fingerprint from step one.
- The recomputationFeed the revealed seed, your client seed and the counter into the published formula, and the result should match what you saw on screen.
What it proves
- The result was fixed before you bet and was not altered afterwards.
- The result follows the published formula.
What it does not prove
- That the published formula has a fair RTP. A fair draw can still have a house edge; every game has one.
- That the casino will pay out, or that your account will not be restricted.
- That a particular casino's implementation is the same as the developer's.
How it looks in Mines, Plinko and crash games
The formula turns random numbers into a game result, and each title does that differently. In Mines the numbers decide which tiles hold the mines, so a verifier can show the whole board after the fact. In Plinko they decide the left or right bounce at every peg of the board, so the landing slot can be recomputed. In a crash game one number decides the point where the multiplier stops.
In every case, the check tells you that the layout, bounce path or crash point matches the commitment. It does not tell you whether the multiplier table pays fairly. For that, see the guide to RTP and house edge and the arithmetic on each game page, such as Mines.
Should you verify?
Most players never do, and that is fine. The value is that anyone can, so cheating would be detectable. If a game offers it, find the fairness or verification menu, change your client seed, and try verifying a round once. Many instant games such as Mines and Plinko, and some crash versions, offer this; check each game, because not all do.
A short verification routine
- Open the fairness or provably fair menu in the game and write down the hashed server seed before you play.
- Set your own client seed to something you chose, not the default.
- Play a few rounds at the minimum stake and keep a note of the round counter.
- Rotate the seed so the server reveals the old one.
- Paste the revealed seed into the casino's verifier, or into an independent tool that uses the same formula, and compare the outcome with your notes.
If your own recomputation and the casino's page disagree, treat that as a reason to stop playing and ask support, not as something to ignore.
Read this first. Rocket Multiplier is an independent guide that earns a commission when readers sign up at partner casinos. Gambling laws differ by country and province. Our partner, RooRoll, is an offshore casino; we have not verified a licence from any Canadian provincial regulator and you should assume none. Offshore casinos sit outside local consumer protection. 18+ only (19+ in most Canadian provinces). Help: responsible gambling.
Glossary: six terms worth knowing
| Term | Meaning | Example |
|---|---|---|
| RTP | Share of stakes returned to players over a very long run | RTP 96% = on average 4 lost per 100 staked |
| Volatility | How widely results scatter around the average | Rare big wins = high volatility |
| House edge | 100% minus RTP | 3.5% at RTP 96.5% |
| Turnover | Sum of all stakes in a session | 100 rounds of 5 = 500 turnover |
| Wagering | Times a bonus must be played before withdrawal | 100 bonus at 35x = 3,500 turnover |
| Session budget | Money you can lose without harm | Set before play, never during |
Why a verifier is not a licence
A working verifier proves one narrow thing about rounds you already played. A regulator, by contrast, can inspect the source code, audit the payout percentage and force a casino to pay or lose its permission. Provably fair adds transparency to a game; it does not replace the legal protections a licence gives you, and an offshore casino like our partner offers fewer of those whatever it says about its seeds.
Set limits in five minutes
- AmountHow much per month can go to entertainment without touching bills.
- TimeSet an alarm when the session starts.
- Break ruleAfter a losing run, take 15 minutes before changing anything.
- Exit ruleWinning past your plan is also a signal to stop, not to raise stakes.
Myths and facts
| Myth | Fact |
|---|---|
| A game is "hot" after a losing run | Rounds are independent; the last result does not affect the next |
| A bigger stake improves your odds | It raises the amount, not the probability |
| The demo shows when the game will pay | The demo shows the mechanics, not future results |
| Predictors and signal groups work | They cannot know a random result |
| A bonus is free money | It carries wagering rules and limits |
18+. Partner link - we earn a commission on sign-ups. Offshore casino; read the legal note.
Provably fair: questions
Does provably fair mean I will win?
No. It concerns integrity of the draw, not your odds.
Do all crash games use it?
No. Check the game's fairness menu.
Is a hash a secret code?
It is a fingerprint that cannot be reversed. It allows verifying the revealed seed without exposing it beforehand.
What if verification fails?
Screenshot the data and contact support and the licensing body listed in the casino's footer.