Hearthstone can be played in many ways, but the most challenging has to be Arena, where you are given random Hero Classes and random cards to battle against other randomly build decks for prizes. Your initial 150 gold purchase does net you a pack even if you fail, but the best prizes come at the end, at 12 wins you get a bunch of gold and other goodies. Just don’t lose 3 times, then your run is over, so it can be difficult to get up to 12. One player that seems to hit that mark constantly is Kripparrian, and on his YouTube channel, he has a video to show just what you need to hit that 12 win prize pack. No surprise, a bit of luck is always needed, as the random elements of Hearthstone control almost everything. Check out this video if you want to dive into Arena.