Everyone in crypto gambling says they’re “provably fair.” But if you look closely, most of them only prove the final number after the spin or roll. They never prove how that number was chosen, or if your bet was even part of the process.

That’s what I wanted to fix.

I built something called the ProbablyFair Verifiability Layer (PF-VL). It’s an open standard that makes real fairness provable for any RNG-based game — slots, dice, plinko, whatever.

It doesn’t use a blockchain. It doesn’t use tokens. It’s just math.

Every bet carries a few guarantees:

1. The exact RNG code and parameters are published and hashed. 2. The game logic (payout tables, reels, etc.) is locked and verifiable. 3. Every bet is included in an append-only ledger with a proof. 4. Any player can replay and verify the result themselves. 5. Independent watchdogs can recompute everything continuously.

ProbablyFair doesn’t replace the casino’s system. It sits beside it. Operators don’t have to rebuild anything — just add a few calls to the SDK.

That’s it. Three API calls and one file hash.

If there’s a free, open, drop-in standard for provable fairness, then there’s no reason not to use it. Any casino that refuses is showing you something: they prefer a system where players can’t see what’s really going on.

If it’s fair, you can prove it. If you can’t prove it, it isn’t fair.

Technical bits: Core: Rust (verifier) SDK: Go (operator libraries) WASM: TinyGo (browser verifier) License: Apache-2.0 / CC-BY-4.0

Spec: https://probablyfair.org/specification | https://github.com/ProbablyFair/pf-specs/blob/main/PF-VL-1.0...

Repos: https://github.com/probablyfair/pf-core https://github.com/probablyfair/pf-sdk https://github.com/probablyfair/pf-wasm https://github.com/probablyfair/pf-specs

ProbablyFair Verifiability Layer (PF-VL-1.0) Every bet: committed, included, reproduced.

https://probablyfair.org