Algorand Mainnet -- VRF Beacon #1615566206

Every outcome derived from on-chain VRF beacon output. Verifiable by anyone. No house secret, no trust required.

[ Play Coinflip _] How it Works
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How It Works

Commit-reveal via on-chain VRF. No server involved in outcome derivation.

01

Commit

Your flip() transaction commits to VRF beacon round N+8 (~22 seconds ahead). Your salt hash is stored on-chain -- the house cannot predict or influence the outcome.

02

VRF Beacon

Applied Blockchain's beacon (app ID 1615566206) publishes a VRF output for round N+8. This output is tamper-proof and unpredictable before the round occurs.

03

Resolve

resolve() reads the beacon output via inner app call. outcome = SHA-256(beacon_output ++ your_salt_hash)[0] % 2. If you win, HouseTreasury pays out instantly on-chain.

// On-chain outcome derivation (AVM, Puya Python)

randomness = arc4.abi_call("must_get(uint64,byte[])byte[]", commit_round)
beacon_output = randomness.bytes[2:]  # skip ARC-4 length prefix
combined = beacon_output + salt_hash
outcome = sha256(combined)[0] % 2     # 0=tails 1=heads

Every flip generates a shareable VRF proof card PNG -- play to get yours.

How a Coin Flip Moves the Economy

Per-epoch HEADS rate plotted against a synthetic global market index. Patterns emerge.

Correlation coefficient: 0.94 · Statistical significance: p < 0.001 · Source: this chart

Live Stats

Refer & Earn

Live · on-chain

Every flip your crew makes pays you 1%. Forever.

No claim flow, no dashboard to babysit. The contract sends 1% of every referred stake straight to your wallet the moment a flip resolves — win or lose. It comes out of the house rake, so it never touches their payout.

01

Share your link

app.fairground.quest/?ref=<you>. Every proof card you post already carries it as a scannable QR — sharing a win recruits for you automatically.

02

They flip

Win or lose doesn't matter — every resolved flip counts. The 1% is skimmed from the house's cut, never from their stake, so there's nothing for them to lose by using your link.

03

You earn

The contract pays your wallet on every resolve, on-chain, instantly. Nothing to claim, nothing to trust — it's an inner transaction you can read in the explorer.

[ Get your referral link _ ]

Fixed 1% (REFERRAL_BPS = 100) · self-referral blocked on-chain · paid from house rake, not the player's bet

Document 003 // binding

Terms of Fairness

Classification: Public
  1. §1 — Derivation. The outcome of every flip is SHA-256(beacon ⊕ salt)[0] mod 2. Neither charm, persuasion, nor prayer constitutes a valid input to the outcome function.
  2. §2 — The house. The house edge is fixed in contract bytecode at application 3585680948. It cannot be raised mid-game, including by the house. The house has read the same source code as you.
  3. §3(b) — Operative recovery clause. If the resolver fails, any wallet may trigger a full refund after 48 hours. Your funds are never the keeper's hostage. [REDACTED — see §3(c)]
  4. §4 — Finality. Consensus is not an opinion. Once written, the result exists whether you refresh the page or not.

Filed on-chain · Algorand mainnet · Witnessed by every full node · No signature required

VRF Proof Card

Every flip generates a shareable PNG proof card. Verifiable by anyone on-chain. 

      .:-==-:.
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  +*#%@@@@@@@%#*+
 -#%@@@@@@@@@@@%#-
.+%@@@@@@@@@@@@@%+.
=*%@@@@@@@@@@@@@%*=
+#@@@@@@@@@@@@@@@#+
=*%@@@@@@@@@@@@@%*=
.+%@@@@@@@@@@@@@%+.
 -#%@@@@@@@@@@@%#-
  +*#%@@@@@@@%#*+
   .=+*##%%##*+=.
      .:-==-:.
HEADS · WON
+0.980
ALGO
FAIRGROUND.QUEST
COINFLIP // FAIRGROUND
Proof of Fairness
WALLET
degen.algo
VRF Beacon Round
62184291
VRF Beacon Output
f3a9c2e1…d4c3b2a1
Transaction ID
R5VUZJNZ…QVSR3K7Q
Derivation
SHA-256(beacon ++ salt)[0] % 2
REFMETAFGSCAN TO PLAY · PROVABLY FAIR