This document describes a 4-week hackathon to build blockchain projects on the Internet Computer platform. Participants will learn about blockchain, answer challenges, and have opportunities to win prizes. Past Encode hackathon winners are highlighted. After the hackathon, participants can learn new skills, get hired in blockchain, become ambassadors, or get funding. The hackathon will run from October 6-31 with workshops, support calls, and final submissions due by October 31 for judging and prizegiving in mid-November.