One of the more interesting things in Marvel: War of Heroes is the mastery system. Every card has a certain mastery number, once that number is hit the stats of the card increase significantly.
What is the point of mastery?
I see mastery serving several purposes. Purpose one being that it gives people something to work toward other than simply feeding cards for skill ups and levels. The second purpose is it adds an extra dimension to the basic two card evolution.
Some tips on mastery:
1) Max a cards mastery before evolving it in order to gain the bonus stats. This normally equals something around 100 attack points and 100 defense points per card but it all depends on the amount of stats given as the mastery bonus.
2) When a card is evolved at maximum mastery (lets say for this example it's 30) it will retain that 30 mastery in its final form. So if you have two max mastery cards you're evolving the final one will have 60 mastery out of whatever the evolved cards requirement is.
3) The fastest way to gain mastery is to attack opponents that are higher level than you. You will gain 3/4 Mastery for each card in the attack deck. If the opponent is lower level you gain 1pt. If you have one card you're looking to gain mastery on and you find somebody with really low defense you can do multiple attacks with a one card deck to gain quickly.
4) You can randomly gain mastery during quests. The card chosen to gain mastery is from an attack/defense deck that is the TOP PRIORITY, but the deck can not be the 'recommended' you need to custom create and increase priority on it. If all cards in it are mastered, a random card will gain the points.
Hope this helps people understand mastery.