Card-Forge/forge — reverse-engineered prompt

Build me an unofficial Magic style card game app called Forge, focused on being a solid rules engine and playable client. I want people to be able to play on desktop and Android, with single player modes against AI and the option for online play.

The main experience should include an adventure mode where the player explores a world map, fights different AI opponents, and collects cards or items over time. Also include faster quest style modes without exploration, plus AI formats like sealed, draft, commander, and cube.

Please make it in Java and keep it extensible so new cards, rules, formats, and features can be added later by contributors. It should feel like a community open source project, with clear setup instructions, a user guide, and sane defaults for saving player data between updates.

Look up current docs online if you need to.