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 Adventures: Lord of the Clans
Following the end of "Warcraft Adventures" development, Blizzard Entertainment publicly clarified that it would revisit the "Warcraft" universe in the future. In May 1999, the company announced an impending agreement with an unnamed publisher to release three "Warcraft" novels, alongside novelizations of "StarCraft" and "Diablo". The deal was ultimately signed with Pocket Books. Early in the development process for the "Warcraft" book trilogy, Bill Roper hinted that "Warcraft Adventures" story could reappear in one of the novels. This resulted in "" in October 2001, written by Christie Golden and intended to set the stage for "Warcraft III". The book is considered canonical. According to Golden, "Chris Metzen liked the story line and wanted to see it live in some format." Receiving the assignment after its first author had failed to finish it, Golden was given a six-week deadline for "Lord of the Clans", based on a modified version of Metzen's original plot outline from the game. She proceeded to write several other novels for Blizzard because of her enjoyment of this project, among them "", the company's first "New York Times" Best Seller. Blizzard hired her to a full-time position at the company in 2017.