How to Set a Strong Client Seed for Provably Fair
Your client seed is part of every RNG input. Replacing the auto-generated default with your own value is paranoia-grade fairness insurance.
What the client seed does
RNG input is HMAC-SHA256(serverSeed, "${clientSeed}:${nonce}" + gameSalt). Both seeds contribute to the result.
The server seed gets hashed and committed before the round. The client seed is yours — set it to anything you want. The default is auto-generated random. You can override.
You probably don't need to set a custom client seed. But the option being there matters more than most players use it.
Why custom seeds matter
If you trust the auto-generated client seed, the verifier already proves the round's outcome was determined cryptographically. That's verifier-safe.
If you want stronger guarantees — say, paranoia that the auto-generated client seed could be influenced by an attacker who compromised your session — set a custom seed only you know. Now the server can't pre-derive any specific outcome for you, because it doesn't know your seed.
How to set one
Account Settings → Provably Fair → Client Seed. Enter a 16-256 character string. Save. The new seed applies to your next round.
Good seed material: random bytes, a long passphrase, your birthdate plus salt, a UUID. Avoid short numerics, dictionary words, or anything trivially guessable.
Rotation strategy
For maximum protection: rotate weekly. Even a brief seed compromise can't affect rounds outside that seed's active window.
For typical players: set once at signup, rotate quarterly. The marginal protection from more frequent rotation is small relative to other risks.
Frequently asked questions
- Does a custom client seed change my odds?
- No. The mathematical edge is identical regardless of seed value. Custom seeds change WHICH outcomes you get from a given server seed, not the probability distribution.
- Can I set different seeds per game?
- Currently the seed is account-wide. Per-game seed support is on the roadmap.
- What if someone guesses my client seed?
- They can't pre-derive outcomes — that requires the server seed too, which is only revealed after the round. The client seed alone is not a security vulnerability.
- Is the auto-generated seed safe?
- Yes. Cryptographically random. Custom seeds are a paranoia-grade upgrade, not a fix for an actual vulnerability.