Provably Fair

Provably fair systems typically combine a server seed, a client seed and a nonce. The operator publishes a hash of the server seed before play, so it is committed but hidden; the player can supply or change their own seed; after the round the server seed is revealed and the player can recompute the result and check it against the published hash. If the outcome matches, the operator cannot have altered it after seeing the bet.

The mechanism emerged in crypto gambling as a substitute for the trust that licensing and independent testing provide in regulated markets. It is genuinely useful for verifying that a specific result was not manipulated, but it is important to be precise about what it does not do: it says nothing about whether the odds are fair, whether the operator is solvent, or whether winnings will actually be paid. In regulated markets, testing-house certification and licence conditions address those questions, which is why provably fair is best understood as a complement to regulation rather than a replacement for it.