Provably Fair

Provably fair is a way to prove a game’s result wasn’t altered after you played it, using nothing more than a hash function and numbers you can check yourself. This page explains how it works at Spino and how to actually run the verification, not just take our word that it’s fair.

The Three Inputs

Every provably fair round uses three values: a server seed, generated by Spino and kept hidden until the round settles; a client seed, which you can set yourself or accept a default for; and a nonce, a number that increases by one with every round you play using the same seed pair. Combined, these three values determine the round’s result.

The Hash, Published Before You Play

Before you place a bet, Spino publishes a cryptographic hash (typically SHA-256) of the server seed — not the seed itself, since revealing that would let you predict future results, but a hash of it, which is a one-way fingerprint that can’t be reversed to find the original value. That published hash is your proof that the server seed existed and was fixed before the round happened.

Verifying a Result Yourself

Once you rotate seeds (usually by requesting a new server seed, which reveals the previous one), you can check any past round in three steps: take the revealed server seed, your client seed and the round’s nonce, run them through the same hashing process the game uses, and compare the result against the outcome you were shown at the time. If they match, the round was decided fairly and wasn’t altered after you played it. Most provably fair games include a built-in verification tool that runs this check for you.

Provably Fair vs a Standard License

A gambling license typically means an independent lab has tested the game’s random number generator and confirmed it behaves as advertised, on average, over a large sample — you trust the lab and the auditor. Provably fair is a different, additional guarantee: you can check the specific round you played, individually, without needing to trust anyone’s testing process. The two aren’t mutually exclusive — a game can carry both.

Where It Applies

Provably fair verification covers the games built on Spino’s own seed system, including the spin the wheel bonus. Live-dealer-style games that stream video instead of generating a result from seeds work differently and aren’t verified the same way — check a specific game’s rules page to see which system it runs on.

What Provably Fair Doesn’t Change

Verifying a round proves it wasn’t tampered with — it doesn’t change the odds built into the game itself, and it isn’t a way to predict or influence a future result. A provably fair slot with a low return rate is still a low return rate; what you’ve gained is the ability to confirm the number you were shown is the number that was actually generated, nothing more.