Provably fair, in plain words

"Provably fair" means you do not have to take our word that a game is fair. You can check it yourself, with a bit of maths that anyone can repeat.

Here is the idea, without the jargon:

1. Before you play, you are shown a fingerprint (a hash) of the server seed, the secret that decides your results. 2. Each result comes from that server seed, your own client seed, and a counter that goes up with every bet. 3. When you rotate your seed in the fairness panel, the old server seed is revealed. 4. You hash it yourself and compare it with the fingerprint you saw before. Then you can recompute every result.

If anything had been changed along the way, the numbers would not match.

Crash works a little differently, because everyone shares the same round. It uses a public chain of seeds instead, fixed in advance.

The Fairness page explains both methods in more detail.