Provably fair
The outcome of every case and upgrade is decided by the server — but in a way that it cannot tailor the result to a player, and the player can recalculate everything on their own. This is done with two seeds, a server one and a client one, and a game counter.
How it works
- 1
Before you play, you see the server seed hash
The server seed is a random string the server keeps secret while you play with it. Only its SHA-256 hash is shown in advance: the hash does not reveal the seed, and the seed cannot be replaced after a game without changing the hash.
- 2
The client seed is yours
You can type your own. The server picks its seed before it learns yours, so it cannot choose a pair that produces a desired result.
- 3
Every game takes the next number
Each game in a seed pair has its own sequence number. The same trio of server seed, client seed and number always gives the same result.
- 4
Rotating seeds reveals the previous one
When you rotate seeds in your profile, the server shows the previous server seed in full. Every game played with it can now be recalculated.
Formulas
Game value
hmac = HMAC-SHA256(key: serverSeed, message: "clientSeed:number")
value = first 13 hex characters of hmac as a number (52 bits)Case
Every item in a case has an integer weight; the chance of an item is its weight divided by the sum of all weights.
ticket = floor(value × totalWeight / 2^52)Items go in a fixed order. The drop is the first item whose cumulative weight is greater than the ticket.
Upgrade
chance = min(cap, floor(stakePrice × edge / targetPrice))
roll = floor(value × 1 000 000 / 2^52)Chance and roll are counted in millionths. The upgrade succeeds if the roll is lower than the chance. The pointer on screen stops exactly at the roll.
How to verify your game
Open your profile, go to the Fairness tab and press Rotate seeds. Then, in the History tab, press Verify next to any game: the calculation is repeated right in your browser, without asking the server, and shows whether the result matches.
Go to profile