Provably fair

Every outcome is derived from a hash the player can recompute. We commit to a server seed before play by publishing its hash, and reveal the seed when it is rotated — so a player can check, after the fact, that we did not choose the outcome once we knew their bet.

The scheme#

• Server seed — secret, ours, revealed on rotation.
• Client seed — the player's, changeable at any time.
• Nonce — a counter, incremented once per round.

const hash = sha256(`${serverSeed}|${clientSeed}|${nonce}`);

// The first 13 hex digits give 52 bits — exactly the mantissa of a double,
// so the division below is lossless.
const value = parseInt(hash.slice(0, 13), 16) / 2 ** 52;  // 0 ≤ value < 1

That single float drives the round. What it selects — which tile is a mine, where the multiplier stops — is the game's own mathematics, versioned per release.

The commitment#

Before a round, the launcher can read the current commitment: the hash of the server seed, never the seed.

{
  "fairness": {
    "server_seed_hash": "9c1185a5c5e9fc54612808977ee8f548b2258d31…",
    "client_seed": "player-chosen-or-generated",
    "nonce": 41
  }
}

Rotating and verifying#

Rotation reveals the old server seed and commits to a new one in the same response. With the revealed seed the player can recompute every round played under it.

{
  "revealed": {
    "server_seed": "8f14e45fceea167a5a36dedd4bea2543…",
    "server_seed_hash": "9c1185a5c5e9fc54612808977ee8f548…",
    "rounds": 41
  },
  "next": { "server_seed_hash": "b6589fc6ab0dc82cf12099d1c2d40ab9…" }
}

Setting a client seed#

A player who supplies their own client seed removes any doubt about our influence over the input. Setting one rotates the nonce back to zero.

Versioned mathematics#

Every game release is versioned, and each round records the version it was played under. A change to a payout table is a new release, never an edit — so a round played last year can still be verified against the exact mathematics in force at the time.

Where the randomness comes from#

Server seeds are drawn from the operating system's CSPRNG. Nothing in the engine calls a seeded or time-based generator, and the engine has no access to a player's balance or stake when it computes an outcome — the mathematics and the money are separate layers by design.