A simple design for a cardbox that will hold one deck of Munchkin cards (door or treasure). It fits inside the Munchkin boxes, and with the instructions on top, the cards will stay put in their respective boxes.

What you do is use something pointy, but not sharp, and trace the outline of the box onto some cardboard, or if you have a printer that can handle cardstock, print it out.

Using that same pointy object (I use a sturdy staple remover), score the horizontal and vertical lines. Cut along the outer edges with a box knife, or scissors if you have a really steady hand, and use the box knife to cut along the diagonals, taking care not to go more than about half deep into the cardboard/cardstock.

Fold upwards along the inner score marks, and fold the corners in. They should lie fairly flat against the lengthwise sides.

Let me know if more information is needed.