Blizzard once made a game called WarCraft III. Then someone made an awesome mod for it called DOTA. Then Valve decided to make a game called DOTA 2. Then Blizzard decided to make something called Blizzard DOTA.
And now Blizzard is fighting a legal battle with Valve over the whole thing. What a mess.
Two of the most successful and popular PC developers of all time are squaring off in court over the use of the term DOTA, which stands for Defence of the Ancients.
In 2010, Valve - who is working on a successor to the original called DOTA 2 - began attempts to trademark the word "DOTA", despite the fact it had no historical connection to the property or the genre. At the time, Blizzard said some unkind things publicly about the move, but didn't seem to take things any further.
It has now.
Arguing before the US Patent and Trademark Office's Trial and Appeal Board in an attempt to have Valve's trademark application blocked, Blizzard says that, because the term DOTA has been used by the company's games and fans for seven years, "the DOTA mark has become firmly associated in the mind of consumers with Blizzard".
Valve, on the other hand, well...here's what Blizzard has to say about Valve's upcoming DOTA 2:
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.
Getting into the fine print, Blizzard says that, because the original DOTA required WarCraft III to play - and because it's been using and licensing the term to other companies - that while it doesn't have a trademark on the term, it's got a better case for one than Valve.
In a filing dated November 16, 2011, Blizzard wrote that it "respectfully requests that this Opposition be granted" to Valve's attempts to trademark DOTA (and "Defense of the Ancients", and "DotA", and "Dota").
USPTO Blizzard vs Valve [USPTO, via NeoGAF]