What is provably fair?
Definition and example from our casino glossary.
Definition
Provably fair is a cryptographic method that lets players verify after each round that the result was fixed before the bet and not changed afterwards.
Provably fair systems, common at cryptocurrency casinos, combine a server seed chosen by the casino, a client seed the player can set, and a nonce that counts each bet. Before play, the casino publishes a cryptographic hash of its server seed. Each outcome is derived from all three values. When the seed is rotated, the casino reveals the original server seed; the player can hash it, confirm it matches the earlier commitment, and recompute every result. This proves that outcomes were determined before betting and not altered afterwards. It does not prove that the game's payout percentage is reasonable, that the casino is licensed, or that it will pay withdrawals. Those questions still depend on licensing, terms and track record. Provably fair is a useful transparency tool, best treated as one check among several rather than as a substitute for regulation.