Ironsmith

Ironsmith is a Magic: The Gathering rules engine that compiles card text into executable game effects rather than hardcoding individual cards. It features a parser pipeline that converts Oracle text into structured runtime behaviors, then executes them through an event-driven system handling triggers, replacement effects, combat, and state-based actions. The engine runs in the browser via WebAssembly.

Players can load decks, play solo games for practice (goldfishing), or join multiplayer lobbies to play with others. The project includes a card creation tool for experimenting with custom effects. Currently, approximately 22,000 cards compile, with about 14,000 matching their official counterparts at 100% similarity. The maker reports using LLMs extensively throughout development.