Is it possible to have both 6 unupped and 6 upped of the same card? Yes. Can you use 6 of both in your deck at the same time? No. The total of both unupped and upped versions of the same card must equal 6 (3 Horned Frogs and 3 Giant Frogs, 4 Giant Frogs and 2 Horned Frogs, etc.). Aside from that the only thing you should be wary of is that you may not possess more than 3000 cards at any one time.