Blizzard has announced the next single-player expansion for its collectible RPG card game Hearthstone: Heroes of Warcraft. One Night in Karazhan, where players get invited to a big party, will be released on August 11.

Here's how Blizzard describes the plot of the expansion:

Karazhan, long a potent nexus of arcane energies, is about to become the focal point of a very different kind of cosmic force. The wizard Medivh has used every bit of magic at his disposal to set up the most lavish and extravagant party of all time, and your name is on the guest list alongside the crème de la crème of Azeroth and beyond! With such an eclectic mix of attendees, it's guaranteed that this party will be out of this world. But as you groove to the music and let the sights dazzle you, beware; one night in Karazhan, and even tough guys tumble. Keep your decks straight, your wits sharp, and above all, stay alive!

The new content and features of One Night in Karazhan include:

  • New Cards: Make your way through four wings chock-full of challenging bosses, unexpected twists, and mystical mayhem. Beat the bosses and earn their brand-new cards for your collection!
  • Legendary: Get ready for truly dazzling legendary cards such as Moroes and many more.
  • Class Challenges: As the evening progresses, you will unlock nine all-new class challenges that test your skills in surprising new ways. Succeed, and unlock their rewards!
  • New Game Board: When an archmage throws a party, nothing but the best will do. Prepare to be spellbound by the magic of Karazhan!
  • Never a dull moment: Your host may be a Guardian of Tirisfal, a vastly powerful magic user, and a fantastic dancer, but nobody's perfect. Some matters may transpire over the course of the evening that might require your… special attention. Come prepared!
  • Portals Everywhere: This party is so intense, it's warping the very fabric of space and time to bring in more guests! Use the new portal spell cards to unleash the magic and summon random minions to the field.

Hearthstone players will be able to access the first prologue mission in the One Night in Karazhan expansion for free when it is released.

Download Hearthstone from Blizzard