Hearthstone is issuing a change to one of its new Quest cards, aimed at better balancing. The Rogue Quest, the Caverns Below, will require one more copied minion to be played to activate its effect.
Quest cards for each class were added with the most recent expansion, Journey to Un'Goro, but none of them have stuck to the top of Hearthstone tier lists like the Rogue's. The Quest, which activates after you've played four minions with the same name, rewards you by changing all of your minions to 5/5s. Hearthstone being what it is, the Internet has more-or-less refined it to perfection, giving a smooth entry point to finish the quest and plenty of cheap overpowered minions once the reward is cashed in.
In a statement, Blizzard said that the deck wasn't out of balance with other popular decks, but felt the change was warranted because it was pushing out slower, control-oriented decks. With this change, it will be that much harder to fulfill the Quest requirement, slowing down the deck's win condition enough to give control decks a fighting chance. Blizzard also noted this is important ground-laying for the next expansion.
Quest Rogue blew up quickly when Un'Goro went live, and Blizzard even recognized in an interview with Shacknews that it was just on the edge of being overpowered. A month later, we concluded it wasn't strictly overpowered. Instead, it was the deck the community loves to hate because it just feels cheap when you're on the losing side. Blizzard has made changes in the past based more on feel than strict numerical balance, so this is of a type.
The team also teased a Q&A session coming up this Friday, June 30 at 10:30 AM PT. Ben Brode and Mike Donais will be answering questions on the game's official Twitch channel, so you can get in your question now by tweeting at @PlayHearthstone with the hashtag #QA.