Ethernaut is an open-source, Web3/Solidity-based wargame designed to run on the Ethereum Virtual Machine, offering a unique educational experience for learning Ethereum through interactive smart contract challenges. Each level of the game presents a smart contract that players must exploit, drawing inspiration from historical hacks to provide a rich learning platform. Players can engage with an unlimited number of levels in any order, enhancing their understanding of Ethereum security and smart contract vulnerabilities. The game requires a local setup, involving a test network, contract deployment, and a React frontend that can be executed on localhost. Ethernaut is hosted at ethernaut.openzeppelin.com and actively invites community contributions to enhance and expand its educational scope.