The new special event will be running up until October 21.
Blizzard has kicked off a new special event for Hearthstone: Heroes of Warcraft, a true 'Masquerade Ball' that will offer weekly challenges and rewards up until October 21.
There's quite a few changes in place, like the introduction of four new heroes, 16 minions (with an emphasis on Elementals), and a new progression system, all for Battlegrounds mode. Players will also get to a free ticket to the Arena, which will be focused on Dual Classes until the end of the Masquerade event.
Meanwhile, weekly challenges will be available with several rewards, officially described as follows:
September 29: Play Dual-Class Arena to earn 1 Scholomance Academy pack, 1 Ashes of Outland pack, and 1 Year of the Dragon pack.
October 6: Play 50 cards in any mode to earn 1 Scholomance Academy pack, 1 Decent of Dragons pack, and 1 Year of the Dragon pack.
October 13: Defeat Leoroxx in Hearthstone Book of Heroes: Rexxar to earn 1 Scholomance Academy pack, 1 Saviors of Uldum pack, and 1 Year of the Dragon pack.
Lastly, you can play a new solo experience dedicated to the hero Rexxar, where you will face eight specific bosses controlled by the AI. Considering that the event ends on October 21, it is highly likely we will also see a Halloween event soon after.