Knights of the Frozen Throne expansion has arrived in Americas Region and Card Packs can be purchased and opened! For all players logging in until October 31, a special one-time surprise of 3 free card packs will await them. Note that Asia and Europe Regions closely follow for launch on August 11 07:00 AM KST and August 11 05:00 AM CEST respectively. For the detailed schedule & regional release estimates you can check out the Official Forums.
Knights of the Frozen Throne is the first game expansion that includes free missions, putting your skills to the test. Additionally the new Hero Cards presented are an entirely new card type that are neither spell, minion, nor weapon. When played, each Death Knight Hero card replaces your hero, casts a Battlecry, dons some hefty armor and provides a potent new Hero Power. Manifesting their power as a Death Knight in a different way, they all offer new possibilities that may transform the way you play Hearthstone.
For additional information you can check out the Death Knight Hero Cards video preview below, or visit the Official Page.