Provably fair is a way to check a supported game's result against published inputs and an algorithm. It is not a promise of profit, a casino licence or proof that every game on a website uses the same system.
What you need before checking
A common design uses a secret server seed, its published hash, a client seed and a round counter called a nonce. The hash commits the operator to a seed without revealing it during active play. Some games also use a cursor, additional inputs or external randomness. Use the documentation for the exact game and version.
A new nonce changes the input, not necessarily the visible result. Two rounds can legitimately produce the same dice value, card or multiplier.
How to verify a completed round
First, save the server-seed hash shown before the relevant bets. Record the round ID, client seed, nonce and any other required values.
Next, follow the game's documented seed-reveal process. The old server seed may be disclosed after rotation, not after every round. Never publish an active secret seed or enter your password into a verifier.
Calculate the revealed seed's hash using the documented algorithm and compare it with the saved commitment. Then reproduce the game's full result calculation, including input order, separators, byte selection and outcome mapping. A matching HMAC alone is not the complete check if the game applies further conversion.
Compare the reproduced result with the recorded round. If they differ, first check the inputs and game version; preserve the evidence and request an explanation.
What a successful check does—and does not—show
A match shows that the recorded result agrees with the committed inputs and the specified calculation. It does not independently establish seed quality, solvency, withdrawal reliability, licensing or the absence of a house edge. Checking a few rounds is not statistical proof of the whole platform.
Look for a verifier and published rules for the specific game. Do not assume that provider slots or live-dealer games support the same verification. No system can make future profits certain.
A reproducible check needs more than a screenshot
Suppose the saved commitment is H and a revealed old server seed is S. First calculate the documented hash of S and compare it with H. Then apply the game's complete outcome algorithm using the recorded client seed, nonce and any additional inputs. These are two separate checks: the commitment matches, and the recorded outcome follows the algorithm. Neither should be replaced by trusting a “verified” label.
Formatting matters. Uppercase and lowercase text, spaces, encoding, input order and the exact game version can change the calculated value. Keep the original inputs rather than manually rewriting a screenshot. If an external verifier asks for an account password, payment secret or active server seed, do not use it. A public verification method should not require access to your balance. Where a game supplies no reveal process or documented mapping, say the check is unavailable rather than assuming another game's formula applies.
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