Booster pack cards consist of

• 40+ Common cards
• 45 Rare Cards
• 40 Epic Cards
• 13 Legendary cards

That's a total of 133+ unique cards to be found in the Alpha Edition Boosters! Booster pack card probability is:

• 65% chance to be Common
• 30% chance to be Rare
• 4% chance to be Epic
• 1% chance to be Legendary

In addition, every card has of course 2 % chance to be Elite.