Hearthstone's latest expansion Knights of the Frozen Throne launched yesterday and if you are a fan of free stuff and the Hearthstone single player content, you should check it out! From now till October 31st for simply logging in you get 3 Knights of the Frozen Throne packs. This expansion also comes with a bunch of new single player content including a prologue and entire Adventure style wing. The rest of the wings open a week at a time ending with the final boss battle with Arthas himself. If you beat Arthas with each of the 9 classes you unlocks the new Arthas Paladin hero!

https://us.battle.net/hearthstone/en/blog/20944003