The newest World of Warcraft expansion sold millions of copies on its first day and helped reinvigorate the MMO's playerbase, Blizzard announced today.

Legion, which is World of Warcraft's sixth expansion, sold more 3.3 million copies on its August 30 launch day. This matches the record set by previous expansions, including 2010's Cataclysm.

Historically, the release of a new World of Warcraft expansion leads to surges in player figures, and this was no different for Legion. The game saw its highest launch-week player concurrency figure since Cataclysm. Blizzard did not share this figure, however.

"It's been a thrill to see players hunting demons, powering up Artifacts, and freely exploring all the new zones in Legion," Blizzard CEO and cofounder Mike Morhaime said in a statement. "We worked hard to make this the best World of Warcraft expansion yet, and we look forward to providing players with even more content as Legion's epic story unfolds in the months ahead."

Next up for Legion is patch 7.1, which is titled Return to Karazhan. This will include a brand-new raid called Trial of Valor, while there will also be a new five-player Mythic dungeon. More quests that play out across multiple weeks are also planned for the update. You can read this Blizzard blog post to learn more about Return to Karazhan.

In other news about World of Warcraft, Blizzard has released a companion app for Legion. The free app lets you explore quests, manage followers, and research and order hall upgrades, among other things.

Previous World of Warcraft expansions have included: The Burning Crusade (2007), Wrath of the Lich King (2008), Cataclysm (2010), Mists of Pandaria (2012), and Warlords of Draenor (2014).