Hearthstone is getting a single-player adventure mode and 30 new cards

One of the hottest new free-to-play games is about to get a bunch of new content.

Publisher Blizzard revealed that it is working on a new mode for its Hearthstone: Heroes of Warcraft collectible-card game. Unlike the Arena and standard battles, this new story will have individual players facing off against artificial intelligence rather than a human opponent. The adventure, called Curse of Naxxramas: A Hearthstone Adventure, will require players to slog through dungeons to take out the powerful lich Kel’Thuzad. Those who do will collect new cards along the way. This new feature is the latest example of how Blizzard is attempting to generate revenue from its popular card battler. Curse of Naxxramas’s global release will likely debut in about one to two weeks.

Blizzard is adding 30 new cards. As you unlock these items in the dungeons, you can immediately start using them in player-versus-player battles. These new cards are called things like “Undertaker,” “Shade of Naxxramas,” and “Nerubian Egg.” The studio didn’t say how many are standard or Legendary cards, although Blizzard is definitely planning a mix of basic and powerful cards.

The Curse of Naxxramas has five different “wings,” as Blizzard is calling them. These will open up one at a time over the next five weeks. The first part, The Arachnid Quarter, is free for all Hearthstone players. Players that wish to continue on into the rest of adventure will have to purchase access with real money or in-game gold. Blizzard did not say how much it will charge for that access.

Naxxramas is also a dungeon that Blizzard added to World of Warcraft for level-80 players. It was widely regarded as one of the most difficult areas as it required 40 well-equipped players to take it on.

The developer is also adding a new game board based on the Curse of Naxxramas quest. Naturally, it will have completely fresh interactive scenery that you can click on while waiting for your enemy to play their cards.

Hearthstone is now out for PC and Mac. It released an iPad version earlier this month in Canada, Australia, and New Zealand. It is already the ninth highest-grossing game in Canada, according to data-tracking firm App Annie.

The card game also represents Blizzard’s most-aggressive move into free-to-play. The company has dominated the subscription-based PC market with its phenomenally lucrative World of Warcraft massively multiplayer online role-playing game. That game is slowly coming back down to Earth, although it still has more than 7 million subscribers (down from a high of 12 million) who pay $15 a month.

Hearthstone is one of the products that Blizzard expects will replace the revenue it has lost from World of Warcraft. Analysts anticipate it will make around $200 million this year in conjunction with the publisher’s upcoming free-to-play online battler Heroes of the Storm, which will compete with juggernauts such as League of Legends and Dota 2.