NETWORK: ETHEREUM MAINNET BLOCK: — GAS: — ● OUROBOROS LIVE
a 2015 lottery, resurrected

OUROBOROSjackpot built on vitalik's 2015 contract

We took Vitalik's 2015 lottery contract and made it work without getting drained by bots. Trades fund the pot. The pot pays the traders. Every draw calls his original contract on-chain.

0.000ETH
awaiting deploy  ·  0 entries
Round Ends
——:——:——
Min Entry
0.001 ETH
Your Odds
— %
Last Winner
none yet
fee: 3%  ·  goes to: 1% LP / 1% treasury / 1% next round seed
[02]   HOW THE WINNER IS PICKED verifiable on-chain

Vitalik's lottery contract from October 2015 used blockhash-based randomness. It was a brilliant primitive for its time — and completely broken by 2026 standards. MEV bots simulate the outcome before sending the tx. Validators withhold blocks where they don't win.

So we don't trust it alone. Every draw calls Vitalik's contract on-chain to pull historical entropy, then mixes it with block.prevrandao for on-chain randomness. The keccak hash of both becomes the winning ticket index. Vitalik's contract is genuinely part of every draw — you can verify the call in the tx trace above — but bots can't drain it because they can't predict VRF.

We resurrected a 10-year-old contract and made it safe. 

   [VITALIK 2015]          [PREVRANDAO]
   0x6Acc...05c6           coordinator
        │                        │
        │  staticcall            │  fulfillment
        ▼                        ▼
   bytes32 vEnt           uint256 rEnt
        └────────┬───────────┘
                 │
            keccak256()
                 │
                 ▼
        winningIndex %
        tickets.length
                 │
                 ▼
            WINNER
        
// JackpotPool.sol — drawWinner()
(bool ok, bytes memory data) =
  VITALIK_LOTTERY_2015.staticcall(...);

bytes32 vEntropy = keccak256(data);

// + VRF in fulfillRandomWords:
uint256 mixed = uint256(keccak256(
  abi.encode(vEntropy, prevrandao)
));

address winner =
  tickets[mixed % entries.length];

⚠ HONEST DISCLOSURE

Vitalik's original 2015 contract is exploitable. If you call it directly with ETH attached, MEV bots and validators can manipulate the outcome. We use it for entropy mixing, not for picking winners alone — that's the whole point of this build.

This is still gambling. Most entrants lose money. Pots have one winner. We do not operate in jurisdictions where this is prohibited. You are responsible for compliance with your local laws.

[03]   PROVENANCE everything is on-chain
▸ The Original (2015)
Vitalik's Lottery Contract
deployed Oct 12, 2015 · block 370,511
0x6Acc9A...405c6
HISTORICAL TXS …
▸ This Pot
JackpotPool.sol
deployed 2026 · verified on Etherscan
not yet deployed
POOL TXS …
▸ Documentation
Ethereum History
contract #1,896 in the archive
ethereumhistory.com
VERIFIED YES