Custom Smart Contract: OddEvenBetting Game Built a betting game where players bet ETH on odd/even...

Custom Smart Contract: OddEvenBetting Game Built a betting game where players bet ETH on odd/even...Custom Smart Contract: OddEvenBetting Game Built a betting game where players bet ETH on odd/even...

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Victor Jojo-Chibuzo

• Oct 28

Custom Smart Contract: OddEvenBetting Game

Built a betting game where players bet ETH on odd/even. Win = 2x payout.

Contract

Uses Chainlink VRF for randomness. Main functions:

placeBet() - player picks odd/even

fulfillRandomWords() - Chainlink callbacks, pays winners

Owner controls for funding/withdrawing. Checks 2x bet amount first.

Testing

28 Foundry tests with VRF mock. Tested wins/losses, permissions, edge cases. 95% coverage.

Deployment

Sepolia testnet. Created VRF subscription, deployed, added as consumer, funded with 0.1 ETH. Cost ~0.02 ETH.

Made helper scripts. Key learning: VRF takes ~1 minute, no instant on-chain randomness.

Works great!

GitHub: https://github.com/Jo-joVictor/Foundry-Lottery-

Etherscan: https://sepolia.etherscan.io/address/0x9e1dadfb93efb79a55b9e11e9b7b76fc57330788

Solidity Solidity OpenZeppelin Smart Contract Development Chainlink

github.com

GitHub - Jo-joVictor/Foundry-Lottery-: A Lottery that allows users to pick between odd and even, then a random number is generated by Chainlink VRF, modulus(by 2) is used to check if the number is odd or even. And users are given 2X their input if their choice is correct.

A Lottery that allows users to pick between odd and even, then a random number is generated by Chainlink VRF, modulus(by 2) is used to check if the number is odd or even. And users are given 2X the…