ProbablyFair | Verify the Dice Aren't Loaded

"Provably Fair" is broken. Here's the fix.

Standard "provably fair" only proves the roll wasn't changed. It doesn't prove the payout tables are real or that the casino didn't pre-select your losing seed. ProbablyFair fixes both.

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What "Provably Fair" Actually Proves

Spoiler: Not much.

What It Proves

The server seed wasn't changed after you bet
The hash matches the revealed seed

That's it. That's all standard provably fair verifies.

What It Doesn't Prove

Payout tables are real - They could show 99% RTP but use 85%
True house edge - The mapping from roll → outcome is hidden
Seed wasn't pre-selected - Server can pick seeds that make you lose

"Provably fair proves the dice roll. It doesn't prove the dice aren't loaded."

ProbablyFair: Complete Verification

Three verification levels. Only Level 3 is fully secure.

"Provably Fair"VULNERABLE

Seed commitment only. No table verification. No timing proof.

✓ Seed hash verified
✗ Payout table hidden
✗ Seed selection attack possible

ProbablyFair BasicPARTIAL

Seed + table verified. Timing not proven.

✓ Seed hash verified
✓ Payout table published
✗ Seed selection attack possible

ProbablyFair CompleteSECURE

Seed + table + timing proof. No known vulnerabilities.

✓ Seed hash verified
✓ Payout table published
✓ Timing proof (Merkle/beacon)

The Stack

Everything you need to verify gambling fairness.

Browser Extension

See the true house edge on any gambling site. Green badge for verified, red for unverified. Works without casino cooperation.

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pf-verify

TypeScript library for verifying bets. Validates seeds, tables, timing proofs, and calculates true RTP. 111 tests passing.

View on GitHub

Public Registry

Immutable database of published payout tables. Cloudflare Workers + D1. Zero maintenance, globally distributed, effectively immortal.

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For Casino Operators

Want to prove you're not scamming? Adopt ProbablyFair.

Publish Your Tables
Register your payout tables in the public registry. Content-addressed, immutable, auditable.
Add Timing Proofs
Merkle tree pre-commitment or beacon-based seeds. Proves you can't pre-select losing outcomes.
Get Verified Badge
Players with our extension see a green checkmark. Competitors who refuse look guilty.

Integration Guide

Level 3 Verified

Your Casino Name

RTP99.90%

House Edge0.10%

Tables Published12

Stop trusting. Start verifying.

Install the extension. See which casinos are hiding their odds.