Hello, thanks for your feedback! I don't think this is a bug, it's my stupidity. I decided that the player should have 16 cards in his deck, and if he has fewer in his library, then the number of cards in the deck should be the same as in the library (so you have to use all cards if you have fewer than 16 cards). I didn't have time to add hints to the window with the deck, so it feels like a bug, sorry =(