Corsual's EXP writes: "The Arena in Hearthstone: Heroes of Warcraft is by far my favourite element of the game, if not the only reason I'm like to play it regularly at launch. In the simplest terms, it's a special game mode with multiple restrictions that, culmatively, create an entirely new way to play.
Essentially, you pay to enter (either using 150 in-game gold earned through quests and rewards, or $1.99) and must then choose a class from 3 random options. Once your class is selected, you'll be asked to build an ad-hoc deck by selecting a card out of three possible options, 30 times.
We checked out the arena today on the Corsual Livestream, with a Rogue Deck. Check out the VOD for a better look at how the arena works, and a stern reminder that in Hearthstone, victory and defeat are almost always only seconds apart:"