How provably fair gets gamed
A badge that says "provably fair" doesn't make a site fair. These are well-known ways the setup can be bent while still looking legit. We built the Proof Ledger so none of them work here, and so you don't have to take our word for it.
Trick 1
The seed shows up after the bet
If you only see the server seed (or its hash) once the round is over, nothing stops the house from picking a seed that suits it. A hash you get late proves nothing.
Kodak: Every seed hash is fixed before you bet and is part of a pre-committed hash chain. Each seed hashes to the one before it, so we can't slip a new one in.
Trick 2
Seeds quietly rotate when you're winning
A site can swap your seed on a hot streak, or never show old seeds at all. Without the full history you can't tell a fair run from a managed one.
Kodak: The whole seed chain is public on the Proof Wall. Every revealed seed has to link to the chain tip, and a gap or a swap breaks the math in front of everyone.
Trick 3
Only the good bets get counted
Publishing some results is easy. Leaving out the losing rounds, or the rounds that didn't verify, makes the numbers look clean when they aren't.
Kodak: Every settled bet goes into an hourly Merkle batch, and each batch chains to the last one. Drop one bet and the root changes, so the anchor stops matching.
Trick 4
You can only check it on their site
If the only verifier is a page the casino runs, it can say PASS no matter what. A check you can't run yourself is just more marketing.
Kodak: The verifier runs in your browser with the same code the games use, and there's an offline script too. Batch roots are posted to GitHub and Discord, outside our database.
Trick 5
Your client seed gets overwritten
Some setups let you type a client seed and then swap it out server-side, or reuse one they chose. If you can't see the seed in the final record, it may not be yours.
Kodak: Your client seed and nonce are written into the bet's ledger leaf and your signed receipt. Change them and the leaf hash and the signature both fail.
Trick 6
Nonces get skipped or reused
Nonces are meant to count up one per bet. Skipping some lets a site burn rolls it didn't like, and reusing one replays a known result.
Kodak: Nonces are in every leaf, in order, sealed hourly. Replay shows the exact nonce your bet used, so a skip or a repeat is visible in your own history.
Trick 7
RTP numbers with nothing behind them
A big RTP on a banner costs nothing. Unless it comes from the actual bets, it's just a number someone typed in.
Kodak: Live RTP is worked out from the sealed ledger leaves themselves, next to the theoretical figure, so anyone can recount it.
Trick 8
The house is the only source of randomness
When one side makes all the randomness for shared rounds, that side can grind seeds until it finds one it likes before the round starts.
Kodak: Crash and duel rounds also mix in the public drand beacon, a randomness feed nobody here controls and nobody can know in advance.
This is about how the systems work in general. It isn't a claim about any particular site.