Card Set is a category that each card is a part of. It should not be confused with Rarity. Players can obtain and use the cards from all sets except Mission and Cheat. All the available cards for each set can be browsed in-game by going to Crafting Mode and choose a given set in the lower right corner.
Basic cards are cards that show as Basic when you right-click them in "My Collection". The basic card set consists of cards that are obtainable through leveling your hero/class and all these cards are Soulbound meaning they cannot be disenchanted nor crafted. Basic cards can be distuinguished from Expert cards because all Basic cards are also of Rarity Free and thus has no rarity gem in the middle of the card. All Basic cards are Soulbound, meaning that they can not be disenchanted. The converse, however, is not true; not all Soulbound cards are Basic, as all the cards in the Reward Card Set are also Soulbound.
For list of Basic cards, see List of Basic Cards.
The Classic card set consists of cards that are obtainable through buying Classic Card Packs or Crafting. All Classic cards have been available from the launch of Hearthstone. This set does not include cards that were added later, such as at the Curse of Naxxramas event. All Classic cards are Common, Rare, Epic or Legendary, while the converse is not true; not all of the cards of those rarities belong to the Classic Card set.
Before the Goblins vs Gnomes expansion Classic set was known as Expert set.
The classic set contains 302 cards, 245 which are collectable, 135 collectable class cards (15 for each class) and 110 collectable neutral.
For list of Classic cards, see List of Classic Cards.
The Reward Card Set consists of Cards that are gained as rewards for completing in-game objectives, like collecting every card of a special subtype. Reward Cards could conceivably be of any Rarity, but at present, there are only two cards in this set and these are of Epic and Legendary Rarity. All Reward cards are Soulbound, meaning that they can not be disenchanted.
For list of Reward cards, see List of Reward Cards.
The promo set is cards that are given out for special (out-of-game) events such as spending real money in the Store during the Beta. These cards are Soulbound, meaning that they cannot be disenchanted.
For list of Promo cards, see List of Promo Cards.
The Naxxramas set consists of 30 cards that were introduced through the Curse of Naxxramas adventure. All of the cards in this set are Soulbound and obtainable only by defeating the Curse of Naxxramas challenges. In the Arena mode however these cards are available to all players regardless of progress in the Naxxramas challenges.
For list of Naxxramas cards see list of Naxxramas Cards.
The Goblins vs Gnomes set represents the first expansion set to Hearthstone. Over 120 new cards were added to the game December 8th 2014 when Goblins vs Gnomes was launched. These cards can be obtained by Crafting or by from Goblins vs Gnomes card packs. They are also fully available in the Arena mode.
The GvG set contains 143 cards, 123 which are collectable, 72 collectable class cards (8 for each class) and 51 collectable neutral.
For list of Goblins vs Gnomes cards see list of Goblins vs Gnomes Cards.
The Blackrock Mountain set consists of 31 cards that were introduced through the Blackrock Mountain adventure. All of the cards in this set are Soulbound and obtainable only by defeating the Blackrock Mountain challenges. In the Arena mode however these cards are available to all players regardless of progress in the Blackrock challenges. For the list of Blackrock cards see list of Blackrock Mountain Cards.
The Grand Tournament, second expansion to Hearthstone contains 132 new cards. Cards in the Grand Tournament set become playable on 24th of August 2015.
For the list of all The Grand Tournament cards see list of The Grand Tournament Cards.
League of Explorers is the third Hearthstone Adventure. Similarly to its predecessors the cards of the League of Explorers card set are only available through defeating the challenges in the four wings. All the cards are available in the Arena mode regardless of whether player has opened the wings of the Adventure. There are in total 43 new cards, five of which are Legendary.
The fourth Hearthstone Adventure, One Night in Karazhan, features 45 new cards and a new game board. As typical for the single player Adventures, these cards can only be obtained by completing the four wings of challenges. In the Arena mode these cards are available for every player regardless of their progress in the Adventure. 
Mission cards consists of all cards that can not be used by players, such as special minions or spells used by the heroes in the tutorial. They could conceivably be of any Rarity, but at the moment, they are all of rarity Free.
For a list of all Mission cards, see List of Mission cards.
The Cheat set is mentioned only in 3rd party reports of patch changes from the Alpha version. It consists of three cards Destory Hero Power[sic], Hand to Deck and Mill 30, all of which were widely overpowered. It is inconceivable that any player will ever get to use these.
- "The Grand Tournament Arrives August 24th!". eu.battle.net. 2015-08-19. Retrieved 2015-08-22.
- "Whispers of the Old Gods – Now Available!". us.battle.net. 2016-04-26. Retrieved 2016-05-21.
- "The Party Begins On August 12!". eu.battle.net. 2016-07-29. Retrieved 2016-11-02.
- "Hearthstone Alpha Patch #2" Newsitem by Fluxflashor on HearthPwn.org, 2013-08-13. Retrieved 2013-11-05.