Provably Fair: What It Means and How to Verify

provably fair is a cryptographic method of verifying that casino game outcomes were determined randomly and weren't manipulated after your bet.

How it works: 1. Before the game, the casino generates a server seed (a random string) and hashes it. You receive this hash. 2. You provide a client seed. 3. Both seeds are combined to determine the game outcome. 4. After the game, the casino reveals the original server seed. 5. You verify that the hash matches, confirming the outcome wasn't changed.

What this proves: That the result was generated before you bet and wasn't changed afterward.

What it doesn't prove: That the casino's original server seed was generated fairly (though this is technically difficult to manipulate in verifiable ways).

How to verify: 1. Note your client seed, the server seed hash, and the nonce (bet number). 2. After the game, get the revealed server seed. 3. Use the casino's verification page or a third-party hash calculator. 4. Confirm: hash(server_seed) equals the previously provided hash. 5. Confirm: game_outcome equals expected_outcome given server_seed, client_seed, and nonce.

Casinos with verified provably fair: Moonbet, TrustDice, BC.Game, FairSpin, Rainbet. Not all games at these casinos are provably fair. Typically only original games (Crash, Dice, Mines, Plinko) implement it.