"Blizzard is suing Michael Donnelly, the creator of the MMO Glider program, which performs key tasks in the game automatically, such as fighting.
Both sides have submitted legal summaries to a court in Arizona.
Blizzard says Glide is a software bot which infringes the company's copyright and potentially damages the game.
In its legal submission to the court last week, the firm said: "Blizzard's designs expectations are frustrated, and resources are allocated unevenly, when bots are introduced into the WoW universe, because bots spend far more time in-game than an ordinary player would and consume resources the entire time." "