Provably fair, explained with Dice
Every gambling site says its games are fair. Provably fair means you do not have to take our word for it: the mathematics of each roll is arranged so that we commit to the outcome machinery before you bet, and you can check the result after. This guide walks through exactly how that works on Dice.
Three ingredients
A roll is derived from three values. The server seed is a secret random string generated by us — before you place a single bet, we show you its SHA-256 hash, a cryptographic fingerprint that locks the seed in place without revealing it. The client seed is yours: a random one is assigned, and you can choose your own whenever you rotate the seed pair in the fairness panel. The nonce is a counter that goes up by one with each bet, so every roll under the same seed pair is unique.
From bytes to a roll
When you bet, the server computes HMAC-SHA256 over your client seed and nonce, keyed with the secret server seed. That produces a stream of bytes, which is mapped to a number between 0.00 and 99.99 — exactly 10,000 equally likely outcomes. The mapping uses rejection sampling: any byte window that would skew the distribution is discarded and the next one is used, so no outcome is ever more likely than another.
Why we cannot cheat
The order of operations is the entire trick. Because the server seed’s hash is published before your bets, we cannot swap the seed afterwards — any change would produce a different hash, and you would catch it immediately. Because your client seed enters the calculation, we cannot precompute favourable outcomes either: we do not know what seed you will choose. The result is a roll neither side could have known or steered.
The honest price
Fairness also means the payout is stated openly. On Dice you pick a target and a direction; your win chance is exactly the share of the 10,000 outcomes on your side of the target. The multiplier is 100 minus the house edge, divided by that chance in percent — at a 1% edge a 50% chance pays 1.98× and a 10% chance pays 9.9×. The edge is shown on the game, never hidden in the odds.
Verify it yourself
Open the fairness panel inside Dice at any time. Rotating your seed pair reveals the previous server seed in plain text; from that moment, every past roll under that seed can be recomputed, and the same inputs will always reproduce the same roll. If a single recomputed result ever disagreed with what we showed you, you would have cryptographic proof. That is the standard every kocasino original is built on.