Before you play, the server commits to a secret server seed by showing you its SHA-256 hash. The result is then computed from that seed, your client seed and a counter called the nonce. Once the seed is revealed, you can recompute the result and confirm the seed matches the hash you saw first.

It shows the result came from the committed inputs. It does not mean you will win.

• Lava Hops: each game's course is fixed by your seed pair before the first hop, and every stone you can pick has the same chance to hold.
• Cases: each case you open takes one number from your seed pair and lands on the drop chances the case page lists.

The other Originals and Case Battles are settled by the DOBER.GG server, and the server record decides each round. Slots and Live Games run on their studios' own systems.

Every signed-in player has their own seed pair. Open Provably fair on Lava Hops to see it: Client seed, Server seed (hashed) and Nonce, plus the Next seed pair that takes over when you rotate.

• The server seed is 64 hexadecimal characters. While it is in use you only see its SHA-256 hash.
• The nonce starts at 0 on a new pair and moves on by one for each Lava Hops game you start and each case you open. Opening several cases at once uses one nonce per case.
• The nonce is shared across the Originals that read the pair, so a Mines round, a Plinko drop or an Upgrader roll moves it on too.
• The Nonce shown is the one your next game or open will use: note it and the Client seed before you play if you want to check that result later.

1. In Provably fair, type a New client seed (up to 128 characters) or keep the one prepared for you.
2. Press Rotate seed. The old server seed appears under Previous server seed, the next pair takes over and the nonce goes back to 0.
3. The dialog checks in your browser that the revealed seed hashes to the server seed hash you were shown before rotating.

Rotate seed is refused while a Lava Hops game or Mines round is still open, so finish it first. Copy the revealed seed before you close the dialog: for case opens it is shown only there, right after rotating.

1. After rotating, open My rounds under Lava Hops and press Verify on a round, or press Verify on the board when a game ends.
2. Verify round lists the client seed, nonce, server seed hash, server seed and round id, each with a copy key.
3. Your browser recomputes the round on its own: the seed against its hash, every hop's outcome, the multiplier and the payout, and shows whether it passes.

Until the pair is rotated, Verify shows the server seed as hidden and offers Open Provably fair. The dialog also prints two openssl commands under Check it yourself.

Case pages have no Provably fair key of their own; the pair is the same one you see on Lava Hops. Before you open, note the Client seed, the Nonce and the case's skins in Price order, because skin values and the list can change between visits. Rotate afterwards, then recompute the open:

1. Compute HMAC-SHA256 with the server seed as the key (its 64-character text) over the message clientSeed:nonce:0.
2. Read the first 4 bytes as an unsigned big-endian number and divide by 2^32. That is the roll, from 0 up to 1.
3. Each skin's weight is its drop chance in hundredths of a percent, so a case's weights add up to 10,000. Multiply the roll by the total weight (10,000) and round down to get the ticket.
4. Walk the skins from the most valuable down (the case page's Price order), adding up weights. The first skin whose running total passes the ticket is the drop.