https://www.polygon.com/2017/11/3/16603684/hearthstone-expansion-kobolds-catacombs-trailer-release-date >BlizzCon 2017 kicked off today with an opening ceremony where the developer announced Hearthstone: Kobolds and Catacombs, the next expansion for the popular collectible card game. >Hearthstone game director Ben Brode took the stage for the big reveal. He called it “a return to the roots of fantasy.”