According to Blizzard, the new mechanic is called “Reveal” and what it does is that it allows players to take a sneak peek at the next card in their opponent’s deck, thus allowing them to make decisions ahead of time and to be better prepared for what’s to come. This mechanic is shown off in a card called Master Jouster.
Basically what the card does is that it reveals the top cards from both your deck and your opponent’s. If the card revealed in your deck costs more to cast than your opponent’s Master Jouster will gain an additional +1 durability, making it a 2/3 creature. If not then nothing happens and your card remains the same, except that both you and your opponent knows what’s coming next.
We expect that there will be other cards that takes advantage of this new mechanic, but for now Master Jouster is one of them. Still no word on when The Grand Tournament will be launched, but in the meantime gamers can go ahead and pre-order a bundle of packets for the game.