Provably Fair

Built on fairness

DuelBet is a provably fair casino. Every game we offer — Mines, Dragon Tower, Keno and Plinko — is decided by a cryptographic commitment you can check yourself, so an outcome can never be altered after a bet is placed, by us or by anyone else.

Before you play, the server generates a secret server seed and shows you its SHA-512 hash up front. You bring your own client seed, and a nonce counts up by one with every bet. Publishing the hash locks the server into its seed, while your client seed makes sure no result can be tailored to you.

result = SHA-512(clientSeed : serverSeed : nonce)

How a result is drawn

The path from seeds to a final outcome is fully deterministic — the same inputs always produce the same result.

  1. Seeds to hash. The client seed, server seed and nonce are joined as clientSeed:serverSeed:nonce:round and hashed with SHA-512 to produce a 128-character hex digest.
  2. Hash to bytes. The digest is read two hex characters at a time, giving 64 bytes (0–255). If a game needs more, the round counter increments and the next hash is appended, forming an endless byte stream.
  3. Bytes to outcome. Each game draws from the stream using unbiased rejection sampling — Mines and Keno shuffle the board, Dragon Tower picks a safe tile per row, and Plinko reads one byte per row to send the ball left or right.

Verify it yourself

Whenever you rotate your server seed, the previous one is revealed. Hash it under Unhash Server Seed to confirm it matches the commitment you were shown, then open the Mines, Dragon Tower, Keno or Plinko tab to replay any bet from its client seed, server seed and nonce and reproduce the exact outcome.