Power

Card power
The power of a card is the average of its attack value and one third of its health. This value is rounded up to nearest integer. Power = ceil[(Attack + Health / 3) /2] where ceil is the ceiling function (round up to nearest integer).

Deck power
Deck power is the sum of the power of all cards in the deck, after rounding.

Card stats
Stats are affected by number of stars and card level. Each star increases stats by 100% of base value. Each level increases stats by 15% of base value. Base values are listed in table of cards.

Attack
Attack = ceil[BaseAttack * (Stars + 0.15 * Levels)]

Health
Health = 3 * ceil[BaseHealth * (Stars + 0.15 * Levels)]

Example
Shaman level 3, 3 stars: BaseAttack = 55.0 Attack = ceil(55 * (3 + 0.15 * 3)) = ceil(189.75) = 190 BaseHealth = 45.0 Health = 3 * ceil(45 * (3 + 0.15 * 3)) = 3 * ceil(155.25) = 3 * 156 = 468

Additional bonuses
Additional bonuses are applied after the above calculation, and in the following order:

Event and gem bonus
Stat = ceil[Stat * (1 + Event)] + Gem1 + Gem 2 where Stat represents either Attack or Health. Event is the event bonus, usually 200%, as a real number, i.e. 200% = 2.

Card Set bonus
Stat = floor[Stat * (1 + Set)] Set represents the set bonus as a real number, e.g. 5% = 0.05, etc.

floor is the floor function (round down to nearest integer).

Summary
Ignoring rounding off errors due to the above calculations, stats can be approximated as: Attack = [BaseAttack * (Stars + 0.15 * Levels) * (1 + Event) + Gem1 + Gem2] * (1 + Set) Health = 3 * [BaseHealth * (Stars + 0.15 * Levels) * (1 + Event) + Gem1 + Gem2] * (1 + Set)