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Plinko Glossary

Provably Fair

Provably fair is a commit and reveal system that makes every plinko drop independently checkable. The casino publishes a SHA-256 hash of its secret server seed before you bet, then reveals the seed later so you can recompute each result yourself.

Provably Fair at a Glance
Term type Cryptographic commit and reveal scheme
Inputs Server seed, client seed, nonce (and a cursor)
Core function HMAC-SHA256(serverSeed, clientSeed:nonce:cursor)
Commitment SHA-256 hash of the server seed, shown pre-round
Per-row output floor(float x 2) = 0 (left) or 1 (right)
What it proves Results were fixed before you bet and are recomputable
What it does not prove A good payout table; the 1% edge is separate

What does provably fair mean in plinko?

It means each drop is derived from a server seed the casino committed to in advance, a client seed you control, and a bet counter. Because the commitment is published before betting, the casino cannot alter outcomes afterward without detection.

The scheme has three actors. The server seed is the casino's secret randomness, locked in by showing you its SHA-256 hash up front. The client seed is yours to change at will, which prevents the casino from precomputing results for a seed pair it chose alone. The nonce counts your bets so every drop under one pair is unique. Fairness stops being a promise and becomes an equation anyone can rerun.

How is a plinko drop computed from the seeds?

The game computes HMAC-SHA256 with the server seed as key over clientSeed:nonce:cursor, reads the digest as bytes, converts 4-byte groups to floats, and takes floor(float x 2) per row: 0 sends the ball left, 1 sends it right.

A 16-row drop therefore consumes 16 floats and yields a 16-step path such as 1,0,0,1,1,0,1,0,0,1,1,1,0,0,1,0. Count the rights, nine here, and you have the landing bin. The animation you watch afterward is theater tracing a result that was mathematically fixed the moment you clicked. All four sites we track run this Stake-style construction, which is what makes third-party verification possible at all.

How do you actually verify a plinko drop?

Rotate your seed pair so the casino reveals the old server seed, confirm the reveal hashes to the pre-round commitment, then recompute your drops from the revealed inputs. Matching paths prove the results were untampered; any mismatch is proof of fraud.

You never need to trust the operator's own checker. Paste the revealed server seed, your client seed, and any nonce into our independent provably fair verifier and it rebuilds the full peg path locally in your browser. One honest caveat: verification proves the randomness, not the price. A perfectly fair game still carries its published 1% house edge.

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Frequently Asked Questions

Can a provably fair casino still cheat at plinko? +
Not on outcomes without getting caught: once the hashed server seed is published and you set your own client seed, any altered result fails verification. What the scheme cannot police is the payout table itself, so always check the multipliers and the stated edge separately.
Do I have to verify every single drop? +
No. The system's power is that any drop can be audited at any time, which makes rigging individual results irrational. Spot-checking a handful of drops after each seed rotation, especially big wins or ugly streaks, is enough to confirm the chain is honest.

Recompute a real drop yourself

Feed any revealed server seed, client seed, and nonce into our verifier and rebuild the exact peg path locally.

Open the Provably Fair Verifier
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