https://www.gamespot.com/articles/free-hearthstone-legendary-card-and-packs-availabl/1100-6455453/

Blizzard has officially launched the new expansion for Hearthstone. Entitled Kobolds & Catacombs, it introduces 135 new cards, several new card types, and a single-player game mode, among other things. Whether you're a new or returning player, there are also freebies to claim right now.