> Not necessarily - the game engine code is also independently copyrightable separate from the story the game is going to tell. Writing a completely different g

> Not necessarily - the game engine code is also independently copyrightable separate from the story the game is going to tell. Writing a completely different game using that code - even if you just distribute level files - might still be an infringement. 1. Don't conflate the game engine code with the assets made available by the game engine. 2. Depending on how the third-party levels are designed, the third-party levels may infringe on the copyright of the original game's levels, but can't infringe on the copyright of the engine code, unless the level files bundle the engine code. Copying (or similarity that almost resulted from copying) is a prerequisite to copyright infringement [1]: > To win a claim of copyright infringement in civil or criminal court, a plaintiff must show he or she owns a valid copyright, the defendant actually copied the work, and the level of copying amounts to misappropriation. If the terms on the game engine restrict what people can make with the game engine or how people can share what they make with the game engine, then the terms on the game engine go beyond the scope of copyright. An EULA can do that. Any contract that isn't just about copyright can do that. [1] https://en.wikipedia.org/wiki/Substantial_similarity#Substantial_similarity_in_copyright_infringement https://en.wikipedia.org/wiki/Substantial_similarity#Substan...