Seed (Provably Fair)

In provably fair crash games, the seed is the source of randomness that determines each round’s crash point. The seed-based system allows independent verification that the outcome was committed to before the round began — and was not changed mid-round.

Types of seeds

Server seed: Generated by the casino server before the round. The server hashes it (one-way function) and displays the hash publicly. The actual seed is hidden until after the round — preventing players from computing the crash point in advance.

Client seed: A value you (the player) can generate or modify. Combined with the server seed, it ensures neither party alone controls the outcome. Even if the server seed were somehow predictable, the client seed adds player-controlled entropy.

Round nonce: An incrementing number added to prevent seed reuse — each round uses the same server seed but a different nonce, producing a different crash point each time.

The combination formula

crash_point = derive(HMAC_SHA256(server_seed, client_seed + ":" + nonce))

The result is deterministic: given the same three inputs, the same crash point is always produced. This is how you verify — after the round, you apply the same function and confirm the result matches.

Changing your client seed

Most provably fair crash games let you change your client seed at any time. This doesn’t affect your odds — it changes the sequence of crash points you’ll see. Some players change seeds after a losing streak as a psychological reset. Mathematically, it makes no difference.

What seeds do not change

Modifying seeds — server or client — does not change the probability distribution of crash points. The exponential distribution and house edge are properties of the formula itself, not the seed values.

Related terms

• Hash — the one-way function applied to the seed
• Provably Fair — the full verification system
• RNG — the broader randomness system seeds belong to