https://www.gamespot.com/articles/new-hearthstone-expansion-kobolds-and-catacombs-ad/1100-6454643/

A new expansion called Kobolds & Catacombs is on the way to Blizzard's collectible card game Hearthstone, and it includes a new single-player mode. During the BlizzCon opening ceremony today, Blizzard announced Dungeon Run, a mode that Blizzard says is "nothing like we've done in the past."

Dungeon Run is a rogue-like single-player experience that's all about defeating bosses, collecting loot, and leveling your character. Players start with a 10-card deck and must defeat eight random bosses, out of 48 total possible encounters. Each time a boss is defeated, you'll be presented with a loot pile--each comprised of three cards--to choose from to add to your deck. If you lose, however, your deck is discarded and you have to start the gauntlet again from the beginning. You don't need to own any cards in order to actually play, as everything is contained to each Dungeon Run playthrough.