While no court cases have directly addressed the legal ramifications of unofficial patches, similar cases have been tried on related issues. The case of
Galoob v. Nintendo found that it was not
copyright infringement by a user to apply an unauthorized
patch to a system (while the scope was very specific to the
Game Genie). On the other hand, the case
Micro Star v. FormGen Inc. found that user-generated maps were
derivative works of the original game. In
Sega v. Accolade, the
9th Circuit held that making copies in the course of
reverse engineering is a fair use, when it is the only way to get access to the "ideas and functional elements" in the copyrighted code, and when "there is a legitimate reason for seeking such access". According to
Copyright law of the United States 17 U.S. Code § 117, the owner of a copy of a program can modify it as necessary for "Maintenance or Repair", without permission from the copyright holder; an argumentation also raised by
Daniel J. Bernstein professor at the
University of Illinois at Chicago. Similar user rights are given also according to European copyright laws. The question of whether unauthorized changes of lawfully obtained copyright-protected software qualify as
fair use is an unsettled area of law. An article of Helbraun law firm remarks, in the context of fan translations, that while redistributing complete games with adaptions most likely does
not fall under fair use, distributing the modifications as a patch might be legally permissible; however, that conclusion has not been tested in court. == Reception ==