When you enter the arena area and agree to a fee payment (cash or gold) you are offered a choice of three classes to play randomly. Have just started and not knowing anything but Mage I am sad to see that is not an option for me. I do see priest and select it. You are then shown 3 cards to chose from. These can be class cards or common to all classes but will all be of the same rarity. You pick a card and another set of 3 with be shown. This continues till you have picked thirty times completing a deck.
Deck chosen and off I go to Match wits with another player I hope is as new as myself or playing cards they know nothing about like I do.
Now you get to play match after match till one of two things happens. You either win a total of nine games or you lose three. Either of these will end your arena run. Guess which I had happen?
Three games later I am looking at the menu to do something else, lol.