Provably fair
Verify a roll
Every roll on this site carries a proof. Paste one here and your own browser replays it: the seed is rehashed, the dice are re-derived through the same engine, and the claim either reproduces exactly or it does not.
How a provable roll works
Before anything is rolled, a secret 32-byte seed is generated and hashed together with the exact roll being made. That hash is the commitment. The dice are then derived from the seed deterministically, so the seed fully decides the outcome. The proof reveals the seed, and anyone can rehash it to confirm the commitment, replay the derivation, and confirm the dice.
A witnessed roll goes one step further: the seed is mixed with a round of public randomness from drand, a beacon run jointly by Cloudflare, EPFL and other members of the League of Entropy, taking the round published after the commitment was made. Nobody, including us and including the person rolling, can know the outcome before that round exists.
What a proof does and does not prove
A verified proof shows the roll is internally honest: the dice really do follow from the revealed seed, nothing was edited after the fact, and with a beacon witness the roll cannot predate the round it used. Shown live, commitment first and result second, it is cheat-proof, because the outcome was fixed before anyone could see it.
What no proof can show is that someone rolling alone did not quietly discard results until they liked one. That requires a witness who saw the commitment before the reveal, which is exactly what sharing the commitment in your group chat before rolling gives you. We would rather say that plainly than pretend the mathematics does more than it does.