// the find
open-duelyst/duelyst
Duelyst is a digital collectible card game and turn-based strategy hybrid, developed by Counterplay Games.
The full source code of Duelyst, a card-strategy hybrid game that shut down in 2020, now maintained by the community as a self-hostable local server. Counterplay Games released it under CC0, so there are no licensing landmines. It's for developers who want to study a complete production game codebase or nostalgia-driven players who want to run their own server.
The codebase is a complete, shippable production game — not a toy or tutorial project. You get the full game loop: matchmaking, deck building, card evaluation engine, replay system, localization (EN/DE/zh-TW), and audio. CC0 license means you can fork it, strip it, or build on it without legal headaches. The CI setup (separate workflows for lint, unit tests, integration tests) is cleaner than most open-source game repos.
Heavy CoffeeScript throughout the core game logic — a language most developers stopped writing in 2018, and one that makes refactoring painful since tooling support has mostly died. The Firebase dependency for real-time state is a significant operational cost and coupling point; running this locally requires a free Firebase account, which means Google has a hand in your 'self-hosted' setup. No public server means the multiplayer experience is a LAN party problem — you need to find your own opponents. The JavaScript ecosystem here is old enough that you'll spend real time untangling dependency conflicts before you can change a single gameplay mechanic.