Exactly like Asik said, just take a look at the game rules and you'll
- Levels deals with your battle points
- Promotions (novice, senior, master etc..) deals with your cards
collection: the more you have (doubles don't count), the better they are
(a 5 stars card get more respect than a 2 stars card) will give you a
Everything (formula etc..) are explained in the game rules.