Provably Fair

Every result is derived from three values: server seed (secret, hash shown up front), client seed (yours, editable), and a nonce that counts up with each bet.

bytes = HMAC_SHA256(serverSeed, clientSeed + ":" + nonce + ":" + round)
float  = bytes[0]/256 + bytes[1]/256² + bytes[2]/256³ + bytes[3]/256⁴

Because the server seed's SHA-256 hash is committed before you bet, the house cannot change outcomes after the fact. Rotate your seed pair any time to reveal the old server seed and verify your past bets (each bet stores its nonce in your history).