Provably fair mystery boxes you can actually check
Every Doodly roll is an HMAC-SHA256 of a pre-committed server seed, your client seed and a nonce. The hash goes public before you open. The seed goes public after. You do the maths yourself.
The formula
digest = HMAC_SHA256(server_seed, client_seed + ":" + nonce) roll = parseInt(digest.slice(0, 8), 16) / 0xffffffff item = first item where cumulative_weight >= roll
Same inputs, same output, every time — on our servers or on your machine.
What the proof covers
It covers the roll. Once the server seed hash is published, the outcome for any given client seed and nonce is locked. We cannot look at your balance, decide you are due a loss, and swap the result — the recomputation would not match.
What it does not cover is generosity. Drop weights and RTP are a separate disclosure, and we publish those too: boxes target roughly 80% RTP, arcade games about 90%, the Upgrader about 92%.
Verify a round in four steps
Open your round history and copy the server seed, client seed and nonce. Paste them into the verifier. Compare the recomputed item against what you received. If they match, the round was honest — and if they ever do not, that is a bug we want to hear about immediately.
Frequently asked
What does provably fair mean for a mystery box?
The site commits to a secret server seed by publishing its hash before your round. After the round the seed is revealed, so you can recompute the result and confirm nothing was changed mid-roll.
How is the outcome calculated?
HMAC-SHA256 over the server seed with your client seed and the round nonce as the message. The digest is converted to a number, mapped onto the box's cumulative drop weights, and that determines the item.
Can I change my client seed?
Yes. Setting your own client seed is what makes the proof meaningful — the site cannot predict the combined input if you choose your half.
Does provably fair mean I will win more?
No. It proves the roll was honest, not that the odds are generous. Read the published drop weights and RTP alongside the proof.
Where do I verify a round?
On the public verifier page. Paste the server seed, client seed and nonce from your round history and it recomputes the exact outcome.
Ready to open your first box?
Start from 5 USDT. Every item value and drop weight is visible before you pay, and every roll is verifiable afterwards.