DragonFireGames I want to suggest some things about those questions. First of all, in my opinion, I think you should allow duplicates, max of 2 during a match, and they could be refundable to coins too. Also, I think you should add trading, different cards will have different values dependent on their rarity. Like commons = 1, uncommons = 2,3, rares = 4,5, epics = 6,7, and so on. (this will also make trading fair so the users will know how good they are)