Naxxramas cards are obtained through defeating bosses in the Curse of Naxxramas adventure. The set comprises 35 cards, 30 of which are collectible, including 9 collectible class cards (1 for each class) and 21 collectible neutral cards. Naxxramas cards can be recognised by the Naxxramas marking (a skull set upon the silhouette of Naxxramas itself) behind the card text, not found on other cards.
Blackrock Mountain cards are obtained through defeating bosses in the Blackrock Mountain adventure. The set comprises 31 collectible cards, including 18 collectible class cards (2 for each class) and 13 collectible neutral cards. It also contains 5 uncollectible cards (Fandral Staghelm later added a 6th), and a new replacement hero and Hero Power. Blackrock Mountain cards can be recognised by a special marking (a series of peaks, separated by jagged lava flows) behind the card text, not found on other cards.
The League of Explorers cards are obtained through defeating bosses in the The League of Explorers adventure. The set comprises 45 collectible cards, including 27 collectible class cards (3 for each class) and 18 collectible neutral cards. It also contains 15 uncollectible cards. League of Explorers cards can be recognised by a special watermark (an explorer's hat) behind the card text, not found on other cards.
