Using a bot in World of Warcraft does break the game's EULA, just not in the way Blizzard was hoping.
The Court of Appeal for the Ninth Circuit has ruled that World of Warcraft players who used the autopilot program Glider are not guilty of copyright violation, even though they technically don't own their copy of the game.
The ruling comes after years of legal action between Blizzard and Glider maker MDY Industries. Blizzard argued that when a player used Glider, he or she was breaking the end user license agreement, and thus didn't have the right to run the game. This meant that the player was creating an unauthorized copy of the game in his or her computer's memory, which infringed on Blizzard's copyright. This argument hinged on the court agreeing that players licensed the software, rather than owned it however, because under the law, owning the game would allow users to make copies as they saw fit.
The court accepted Blizzard's assertion that users only licensed the game, but protected them from copyright suits by saying that the clause in the EULA that prohibited the use of third-party tools like Glider was a covenant - or a promise not to do something - rather than a condition that limited the license itself. This meant that while Glider users were guilty of breaking a contract, they were not guilty of copyright infringement. Being able to sue bot-using players for copyright infringement instead of breach of contract would have been more advantageous to Blizzard, but as the court noted, it would set a precedent, giving software copyright owners greater rights than Congress had afforded to copyright holders in the past