Duplicate protection is flawed
When opening a pack player is supposed to be protected from excess duplicates unless he has collected all cards of that rarity. Currently duplicate protection protects player from getting a copy of a card if he already has 2 copies of it, however it doesn't include other cards from the pack. E.g. when I had 1 copy of Fledging Gryff i received another 3 copies of it in a single pack even if there were other commons I haven't collected yet.
The duplicate protection should treat cards from the pack as cards already existing in the collection.