Blizzard has filed a motion to the US Patent and Trademark Office's Trial and Appeal Board, asking for Valve's DOTA trademark application to be revoked.
In case you missed the drama last year, here is the quick rundown: DOTA, short for "Defense of the Ancients" is the name of a very popular WarCraft III mod. In fact, DOTA was so popular that Valve decided to hire its creator to develop a standalone sequel that is not very different from the original WarCraft III mod. This move didn't sit well with Blizzard who was already working a DOTA sequel itself.
Apart from changing the name of its upcoming game to "Blizzard DOTA," Blizzard did nothing to oppose Valve's move until Valve tried to register DOTA as its own copyright. Blizzard criticized this move publicly, but it never made any legal action until now.
In its motion, Blizzard argues that DOTA was used in WarCraft III for 7 years while it was never used in any Valve product. The motion reads as follows:
"In contrast to Blizzard, Applicant Valve Corporation ("Valve") has never used the mark DOTA in connection with any product or service that currently is available to the public.
"By attempting to register the mark DOTA, Valve seeks to appropriate the more than seven years of goodwill that Blizzard has developed in the mark DOTA and in its Warcraft III computer game and take for itself a name that has come to signify the product of years of time and energy expended by Blizzard and by fans of Warcraft III. Valve has no right to the registration it seeks.
"If such registration is issued, it not only will damage Blizzard, but also the legions of Blizzard fans that have worked for years with Blizzard and its products, including by causing consumers to falsely believe that Valve's products are affiliated, sponsored or endorsed by Blizzard and are related or connected to Warcraft III."
It seems that Blizzard has a strong case here, but let's not forget that Valve has a strong argument too: their game is being developed by the original DOTA creator and the only one that has the original DOTA intellectual rights.