@Jebediah54:

DOTA is not a genre. It stands for the name of a game. It's not some generic term, it does not attempt to explain what the game is about, etc. If you say "Defense of the Ancients" to a person that does not already know the game, he won't have an inkling on what the game is about.

MMORPG is a genre. It is actually a brief description of what the genre is about (massively multiplayer online role playing game), and thus generic and not deserving trademark protection.

You can't really compare them.

Saying a competing game is a DOTA is just like using Xerox in place of photocopier, Gillette in place of razor blade, "to Google" in place of "to search the Internet for". Common usages, misappropriating a brand name, but this does not preclude those brands from being trademarked.

BTW, "WoW-like" can be seen as a sub-genre of MMOs with ample usage of instancing for group content, limits on how many players may join in a group and reap the benefits, little to no sandbox features, little to no death penalties, gear binding used to prevent players from obtaining most group rewards without actually doing the group content, etc. A surprisingly large number of MMOs fit this description, most (if not all) of them appearing after WoW proved successful.

"Diablo-like" was an even more common term back in the day. Given the absurd success Diablo and Diablo 2 had, and the amount of time Blizzard has taken to provide a new game in the series, a huge number of very similar games sprung up. I even purchased a few. And I clearly remember the gaming press calling them "Diablo-like" and similar terms.

@JattTheRogue:

Indie games, and mods - even if released for free - deserve protection just like games from big companies. The fact it's just a bunch of players coding in their fee time and without money to pay a lawyer does not make them any less deserving of copyright and trademark protection.

Of course, DOTA shouldn't be able to distribute the parts from Warcraft 3 together with the mod. But the name "DOTA" was never Blizzard's; DOTA's developers were fee to trademark it from the start. And from the moment the devs removed the parts copyrighted and trademarked by Blizzard in order to release a new game, it's their game, to do as they want - which includes the right to make a partnership with a big Blizzard competitor.

It's the same thing that happens when a programmer makes an iPhone app and ports it to Android. On the iPhone, he was using a series of iOS resources provided, and copyrighted, by Apple. When porting to Android, the developer removes those resources and uses corresponding Android resources provided by Google. This does not reduce in any way the developer's rights to the app, including the associated copyrights and trademarks.