WARNING: You can lose cards in this game!!!! If you accidentially double click on a card you own multiple times to add it to your deck, then sometimes the game will only add one instance of this card to your deck, while removing two or more instances from your cards library. If this happens and you perceive this too late - and fill your deck up to 10 cards afterwards, then you can't get the 'invisible' cards in the deck back! So be careful ... especially when creating decks with bought cards!!!