Warcraft
In 2004, Blizzard Entertainment moved the series away from the real-time strategy genre and released "World of Warcraft", a massively multiplayer online role-playing game (MMORPG). Requiring a subscription fee to be paid to play, it also introduced regular additional content to the series in the form of patches. "World of Warcraft" gained popularity worldwide, becoming the world's largest subscription-based MMORPG in 2008. The game reached a peak 12 million subscribers worldwide in October 2010. "World of Warcraft" has had seven expansions as of 2018. During the production of "", Blizzard co-founder Frank Pearce stated that "If there's a team that's passionate about doing another "Warcraft" [real-time strategy], then that's definitely something we would consider. It's nothing that we're working on right now, we have development teams working on "", "", "Diablo III", and when those teams are all off the projects they're working on, they'll be intimately involved in the discussions about what's next".
Warcraft
The first three games in the "Warcraft" series, including their expansion packs, were all released on both the PC and Macintosh. All of these games were of the real-time strategy genre. Each game proceeded to carry on the storyline of the previous games, and each introduced new features and content to improve gameplay. "" was the first game in the series to feature play over the internet using Battle.net, although this was not included until a later release of the game. "Warcraft II" was also the first in the series to be re-released as a "Battle Chest", a bundled copy of the game containing both the original and expansion. "" was the first game in the series to feature a Collector's Edition, which all subsequent games have released as well. "Warcraft III" and "World of Warcraft" also have both had "Battle Chests" released for them subsequent to their initial release. The "Battle.net" edition of "Warcraft II" was also the first to introduce the use of CD keys to the series, requiring each user online to have their own copy of the game in order to be able to connect. However, a CD key is not yet required to play via a Local Area Network, although speculation is that future games in the series will do so, as another product in Blizzard Entertainment's portfolio, "", is doing so by removing the option for using LANs altogether, requiring the use of Battle.net.