I know the topic is difficult. But - being a programmer and no lawyer - I want to understand it as best as I can. And it would be good to know the legal issue here for all types of works, not just hacked game roms.

My research is that there are laws only against specific cases. One is, removing DRM can be illegal. And another case I found is when releasing a binary patch for a software violates the GPL, because not enough source code was provided.

What I found no answer for is the case where both researched issues seemingly don't apply. When no copy protection is removed, and when there is no original work being copied for distribution.

For example, given that a so called "rom hack" is an unlicensed diff file that can add custom-made levels to a game, what's the law that may prohibit distributing this file?

  • Usually such a diff file also contains some sort of link to the original work, like a hash or specific instructions that make it work. Is there a law that says, such a link from a diff file to an original work to be patched, is a use of this work? (as in fair use and unfair use)

  • Or is there a law that says creating or applying a diff file, which technically fits into another work, is seen as a result of a transformative use of this work? (no patch without someone using and understanding the original work at first)

  • Or is there a law that allows the authors of the original work to give it a license that just forbids creating or distributing unlicensed diff files?

  • Are you asking about the diff file itself, as in it comes with no license, or are you asking about its modification of the target? Copyright exists without a license being required, so issues around derivative works etc certainly come into play here. – Moo Nov 29 '19 at 1:07
  • To be honest, I think I made a big mistake. I believe, the copyright law is simply the one that forbids creating these "rom hack" diff files (derivatives) in the first place, when the patch target is so complicated as Mario game are. When someone is very talented and manages to create them in a "clean room", then okay. But these patch files for playing more Mario levels are probably just illegal, all of them, and I thought they were not, because they are being tolerated. The whole patch technique doesn't make sense, because nobody can hold a complete game rom in their mind. – Andreas Nov 29 '19 at 2:10
  • Creating them is fine, distributing is where copyright comes into play. – Moo Nov 29 '19 at 2:13
  • If the patch only contains your own content, then the patch itself does not violate copyright. A patch just is a list of instructions that says "change this byte to this, and change that byte to that, and so on." For example if you patched a game to include your own artwork, and that patch file contains only your artwork, then there is no copyright issue. – Brandin Nov 29 '19 at 7:31
  • The issue with ROM hacks is the distribution of the ROMs themselves. For example, if you take a ROM and apply your hack (which adds your own artwork), then it doesn't mean you are now allowed to distribute the modified ROM (which often happens). – Brandin Nov 29 '19 at 7:33

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.