Boss cards are cards unique to boss encounters. They may be made available to the player, or limited to the boss itself, but are not available outside of their respective encounters. Most boss cards belong to a single encounter, while others feature in several.
With most boss encounters involving unique mechanics and boss behaviours, it is no surprise that many boss cards are designed to interact with these, and are often instrumental to defeating the boss in question. Not available in regular play, boss cards are free from the constraints of the balancing required for playable cards, and often feature outlandish powers and effects.
The links below provide comprehensive lists of all bosses, boss Hero Powers and boss cards seen in each set of encounters.
Tutorial
For a list of boss cards from the tutorial, see Tutorial boss cards.
Curse of Naxxramas
For a list of boss cards from the Curse of Naxxramas adventure, see Naxxramas boss cards.
Blackrock Mountain
For a list of boss cards from the Blackrock Mountain adventure, see Blackrock Mountain boss cards.
The League of Explorers
For a list of boss cards from the The League of Explorers adventure, see The League of Explorers boss cards.
One Night in Karazhan
For a list of boss cards from the One Night in Karazhan adventure, see One Night in Karazhan boss cards.
Knights of the Frozen Throne
For a list of boss cards from the Knights of the Frozen Throne mission, see Knights of the Frozen Throne boss cards.
Kobolds and Catacombs
For a list of boss cards from the Kobolds and Catacombs Dungeon Run, see Kobolds and Catacombs boss cards.
The Witchwood
For a list of boss cards from the The Witchwood Monster Hunt, see Monster Hunt boss cards.
Puzzle Lab
For a list of boss cards from the The Boomsday Project Puzzle Lab, see Puzzle Lab boss cards.
The Dalaran Heist
For a list of boss cards from the Rise of Shadows The Dalaran Heist, see The Dalaran Heist boss cards.
Tombs of Terror
For a list of boss cards from the Saviors of Uldum Tombs of Terror, see Tombs of Terror boss cards.
Galakrond's Awakening
For a list of boss cards from the Galakrond's Awakening adventure, see Galakrond's Awakening boss cards.
Ashes of Outland
For a list of boss cards from the Ashes of Outland Demon Hunter Prologue and Trial by Felfire, see Demon Hunter Prologue boss cards and Trial by Felfire boss cards.
Book of Heroes
For a list of boss cards from the Book of Heroes see Book of Heroes boss cards.