How to Verify a Casino Game Was Fair
Most casinos ask you to trust them. A provably fair casino hands you the tools to check. The mechanism is called commit-reveal, and it is simple enough to verify yourself in a few minutes: the casino publishes a cryptographic fingerprint of the shuffled deck before you bet, then reveals the underlying seed after the game so you can recompute the fingerprint and the deck. If they match, the outcome was fixed before your money moved and nobody changed it mid-hand. This guide walks the exact steps on Llamabet — including the /poker/verify page, per-hand verify links, and what to look for on a Sui explorer — plus the one thing verification honestly cannot prove.
Verify a hand yourself →What commit-reveal actually means
Commit-reveal is a two-phase cryptographic protocol. In the commit phase, one party locks in a secret value by publishing its hash — the output of a one-way function like SHA-256. A hash works like a tamper-evident seal: any input produces a fixed-length fingerprint, the same input always produces the same fingerprint, and no practical computation can find a different input that produces it or work backward from fingerprint to input. In the reveal phase, the original value is disclosed and anyone can hash it and compare. Applied to a casino, the secret is the server seed that determines the shuffle. Because the hash was published before your bet, the house committed to the deck while knowing nothing about how you would play — and because the hash function is one-way, publishing it leaked nothing to you either. Neither side can cheat: the house cannot swap the deck after seeing your bet, and you cannot derive the deck from the commitment. That is the entire trick, and it needs no trust in anyone's honesty, only in arithmetic.
The exact flow, step by step
Here is the full loop on Llamabet. Step one: before any betting, the server generates a random server seed and publishes its SHA-256 hash on the Sui blockchain — an on-chain transaction that timestamps the commitment publicly and immutably. Step two: you play. The deck order or roll is derived deterministically from the committed server seed combined with a client seed, so your input is part of the recipe and the house could not have precomputed against it. Step three: after the round completes, the server seed is revealed to you in full. Step four: you verify. Hash the revealed seed yourself and confirm it matches the commitment that was sitting on-chain before your bet; then feed the seeds through the published deterministic shuffle and confirm the deck it produces is exactly the deck you were dealt. If both checks pass, the game was decided by a shuffle fixed before your wager existed. If either fails, you have cryptographic proof of foul play — which is precisely why an honest operator publishes the commitment where it cannot be quietly edited.
Verifying poker hands at /poker/verify
Llamabet's poker tables make this concrete with a self-serve verifier at /poker/verify and per-hand verify links in your hand history. Open any completed hand from history and follow its verify link: the page loads that hand's committed hash, the revealed seed, and the derived shuffle, then re-runs the computation in your browser so you can watch the commitment check and the deck reconstruction pass in front of you. Poker hands are also chained — each hand's record links to the one before it — so an operator cannot quietly delete an unfavorable hand or splice in a fabricated one without breaking the chain for every hand that follows. You do not need to verify every hand you play, any more than you audit every receipt from your bank. The point is that you can verify any hand, at any time, without asking permission, and the house knows it. Spot-check the big pots, spot-check a random small one, and the incentive structure does the rest.
What to check on the Sui explorer
For the strongest form of verification, go one layer deeper than the casino's own pages and look at the chain itself. Llamabet publishes its seed commitments as transactions on Sui, which any public Sui explorer can display. Three things are worth confirming. First, existence: the commitment object really is on-chain, created by a transaction anyone can look up. Second, timing: the commitment's transaction and its checkpoint timestamp predate your bets — this is the heart of the guarantee, since a commitment published after the fact proves nothing. Third, content: the hash recorded on-chain matches the hash the verify page showed you. Because Sui transactions are final and immutable once executed, a commitment that passes these three checks cannot have been backdated or edited, no matter what any website says. This is the step that removes the casino from the trust equation entirely: even if you distrust every pixel Llamabet serves you, the chain's record is not Llamabet's to change.
Why this beats an RNG certificate
Traditional online casinos answer the fairness question with a certificate: an accredited lab tested the random number generator and found its output statistically sound. That is not nothing, but look at what it actually proves — that the RNG was fair when tested, in the configuration tested. It cannot prove the certified code is what ran during your session, that the operator never touched the pipeline between audit and payout, or anything at all about the specific hand that just cost you a buy-in. You are still trusting the operator and extending that trust to the auditor. Provable fairness inverts the model: instead of a third party vouching for the process in general, you verify your own outcome in particular, cryptographically, after every round. A certificate says 'someone reputable checked the machine last quarter.' A commit-reveal proof says 'this exact shuffle was fixed on a public blockchain before your exact bet, and here is the math.' One is testimony; the other is evidence. For casino-grade claims, evidence you can recompute yourself is the higher standard.
What verification does not prove
Honesty requires marking the limits. Commit-reveal proves the shuffle was fixed before your bet and delivered unaltered — it does not prove you will win, and it does not change the house edge by a single basis point. A perfectly fair blackjack game still pays 3:2 on naturals with the house holding a small edge; fair American roulette still runs a 5.26 percent edge and European 2.70; Llamabet's dice holds 1 percent. Fairness verification confirms the game you agreed to play is the game you got, at published odds — not that the odds favor you, because in house games they do not, and in poker your edge comes only from outplaying the table. Losing streaks happen in provably fair games at exactly the rate probability predicts, which can be brutal. So verify your hands, enjoy knowing the deck was honest, and manage your bankroll as if every session could lose — because any session can. Provable fairness removes the rigged-game worry from gambling. It does not remove the gambling.
Frequently asked questions
How do I know the casino did not change the cards after I bet?
Check the commitment timing. In a commit-reveal system, the SHA-256 hash of the server seed is published on-chain before you bet. After the game, hash the revealed seed and compare it to that prior commitment. Since no one can find a second seed producing the same hash, a match proves the shuffle existed, fixed and final, before your wager.
What should I check on the Sui explorer to verify a casino commitment?
Three things: that the commitment transaction actually exists on-chain, that its timestamp is earlier than your bets, and that the hash it records matches the one shown in the game's verification page. Sui transactions are immutable once executed, so a commitment passing all three checks cannot have been backdated or edited.
Does provably fair mean I am more likely to win?
No. Provable fairness proves the shuffle was fixed before your bet and delivered unaltered — it does not change the odds. House games keep their published edge (blackjack pays 3:2 with a small house edge, roulette runs 2.70 or 5.26 percent, dice 1 percent on Llamabet), and losing streaks still occur at the rate probability predicts. Verify the game, and bet only what you can afford to lose.