How to Verify Provably Fair Results
Learn how to mathematically verify that every game result on Rust gambling sites is truly random and not manipulated by the house.
What is Provably Fair?
Provably fair is a cryptographic system that allows you to verify that each game result was determined fairly and randomly. Unlike traditional online casinos where you must trust the operator, provably fair systems use mathematics to prove fairness.
Before each game round, the gambling site generates two pieces of information:
- Server Seed: A random value generated by the site (kept secret until after the game)
- Client Seed: A random value you can see and change before playing
These seeds are combined using a cryptographic hash function to generate the game result. After the round ends, the server seed is revealed, and you can verify the result was fair.
Why Verification Matters
Even reputable gambling sites could theoretically manipulate results if there were no verification system. Provably fair systems eliminate this risk by giving you mathematical proof that:
- The site didn't know the outcome before you placed your bet
- The result was generated using true randomness
- No one can predict or manipulate the outcome
Step-by-Step Verification Guide
Before Playing: Note the Hashed Server Seed
Before you place your bet, the site displays a hashed version of the server seed. This is a one-way encrypted version of the actual seed. Screenshot or copy this hash - you'll need it later.
Example: ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad
Set Your Client Seed (Optional)
Most sites let you change your client seed. Use a random string to ensure complete randomness. If you don't change it, the site uses a default client seed.
Example: myCustomSeed_12345
Play the Game
Place your bet and play as normal. The result is generated using the seeds you noted earlier.
After Playing: Get the Unhashed Server Seed
After the round ends, the site reveals the actual server seed (unhashed). Save this along with your client seed and the game result.
Server Seed: abc123randomServerSeed
Client Seed: myCustomSeed_12345
Result: 2.34x (Crash game)
Verify Using a Calculator
Use a provably fair calculator (most sites provide one) or an independent third-party calculator to verify:
- 1. Hash the server seed and confirm it matches the original hashed seed shown before the game
- 2. Combine the server seed and client seed according to the site's algorithm
- 3. Calculate the result and confirm it matches what actually happened in the game
Common Verification Methods by Game
Crash Games
Crash games use the seeds to generate a crash point (multiplier). The algorithm typically:
- Combines server seed + client seed + nonce (round number)
- Creates a SHA-256 hash
- Converts the hash to a number between 0-1
- Applies a formula: crash_point = 99 / (1 - random_number)
Result: If the calculated crash point matches what happened in the game, it's provably fair.
Roulette
Roulette verification determines which number/color wins:
- Hash server seed + client seed + nonce
- Convert hash to decimal number
- Apply modulo 37 (for numbers 0-36) or modulo 3 (for colors)
Result: The calculated number should match the winning number in the game.
Dice / Mines / Plinko
These games generate random numbers within a range:
- Hash combines seeds and an event counter
- Take first X characters of the hash
- Convert to number and map to game range (e.g., 0-100 for dice)
Result: Calculated roll/outcome matches the actual game result.
Important: What to Watch For
- Hash must be shown BEFORE you bet - If the site shows the hash after you play, they could manipulate results
- You must be able to change your client seed - This prevents the site from pre-calculating results
- Independent verification should be possible - Don't rely solely on the site's calculator
- Algorithm should be public - You need to know exactly how seeds generate results
Third-Party Verification Tools
On-Site Verifiers
Most Rust gambling sites provide built-in verification tools in your account settings or game history. These are convenient but always verify on at least one independent tool as well.
Location: Usually under Settings → Provably Fair or Game History → Verify
Independent Calculators
Use third-party tools that implement the same algorithms. Search for "[site name] provably fair calculator" to find independent verifiers created by the community.
Recommended: GitHub repositories with open-source verification code
Manual Verification Example
Here's a simplified example of manually verifying a Crash game result:
Given:
Server Seed: server_abc123
Client Seed: client_xyz789
Nonce: 1
Step 1: Hash the server seed (SHA-256)
Result: ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad
Step 2: Verify hash matches the one shown before the game
✓ If it matches, the server seed wasn't changed after you bet
Step 3: Combine seeds and calculate result
Combined: server_abc123:client_xyz789:1
Hash: 4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b
Result: 2.34x
✓ Result matches the actual game outcome - Provably Fair Verified!
Only Play on Provably Fair Sites
Never gamble on sites that don't offer provably fair verification. It's your only guarantee that games aren't rigged against you.
Need help verifying a specific game? Contact us