To celebrate Hearthstone's 6th Anniversary, Blizzard is holding a limited-time event: The Spirit of Competition — and this Tavern Brawl is the first .
The idea behind this Brawl is simple but original. When you start playing, you'll receive a random deck. If you lose, then your deck will be destroyed and replaced by your opponent's. In case of victory, that's the contrary — meaning that the real stake is to try to win as much as possible with a specific deck to eventually ensure that everyone will be playing the same one.
By winning this Tavern Brawl you'll get your usual classic pack, but the real interest is to continue playing to defend your deck and see which deck will finally dominate the brawl. If you lose, then it's your chance to fight for a new deck and try to do better!