非官方补丁

Galoob v. Nintendo found that it was not 盗版 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 衍生作品s of the original game. In 世嘉訴Accolade案, the 美国联邦第九巡回上诉法院 held that making copies in the course of 逆向工程 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 美国版权法 17 U.S. Code § 117, the owner of a copy of a program can modify it as necessary for "Maintenance or Repair",[17] without permission from the copyright holder; an argumentation also raised by Daniel J. Bernstein professor at the 伊利諾大學芝加哥分校.[18] Similar user rights are given also according to European copyright laws. The question if and which copyright holder unauthorized changes of lawfully obtained software are fair and beneficial, is a long-standing debate among academic scholars.[19] An article of Helbraun law firm remarks in the context of fan translations that redistributing complete games with adaptions most likely does not fall under fair use, but in patch form it might fall under fair use, while this was never tested in court.[20]