Here's a strategy that has really boosted my winning percentage. A lot of games, it can make the difference between a win and a loss.
The strategy comes down to timing, and the order you put your cards in.
The way I notice the game working is that when several cards activate at once, they activate from left to right. In other words, if you want to give a spell or an attack priority, you move them to the left side of the deck.
A few examples of how this worked for me:
1) Gargoyle / Heals. One of my favorite combinations is the Gargoyle / Heal. You put up the Gargoyle and keep him healed as he gains in armor. Both cards are on a 9 second cooldown, so unless something causes a delay (like Blizzard or Paralysis) they hit at the same time. When I would go up against a Succubus Queen, I would normally heal my Gargoyle, who would then attack the Succubus Queen. The first few hits are fine, but when she gets low on health, so does my Gargoyle. When I rearranged it so the heals came second, I would hit the Queen, loosing a ton of health, then instantly be healed (unless the enemy had something in cooldown as well that finishes me off). I went from loathing from Succubus Queen to tolerating it (it is still a deadly card).
2) Heals / Heals / Death Tower. It kills me when my death tower goes in for the kill on a weak card and then gets sabotaged. Then I realized it is on that same 9 second cooldown. Now I list it third. They could throw two sabotages at me and my death tower will still strike every time. They have to have three of them in order to prevent that, in which case they probably have a pretty weak field to beat anyway. Luckily, there is no way for the "enemy" to adjust the cooldown of a spell card so they will always go off at the time.
Think about this when assembling your deck, and put your priority attack cards to the left to use them first or to the right to prevent them from being interrupted by something else. Even a 6-second / 9-second card will launch at the same time a third of the time.
Just... don't do this when you face me. Deal?
Pr0digy
Caveat: This works best with quick games. If you throw out your stronger cards during a pro game, where your enemy can see your first four cards, they might be able to counter it in some way. If you show the ace up your sleeve too soon, a clever player will find a way to counter your brilliant attack strategy.
