Anything goes at an ABC party. Anything but clothes, that is, so it will be up to you to get creative and fashion your outfit out of other materials and objects from around the house. The playing card dress is a fun, easy-to-assemble costume idea that doesn't require much more than a black bin liner and a few decks of playing cards.
Cut a hole in the bottom of the bin bag that's large enough to fit your head and neck through. This will allow you to wear the bin bag like a dress.
Cut holes on either side of the bin bag for your arms to fit through. To make sure you get the positioning right, put the bin bag over your head first so you can mark where the arm holes should be.
Lay the bin bag dress on a flat surface and start sticking playing cards to the bin bag with glue with the number side showing. Start from the bottom and work your way up, layering the cards until both sides of the bin bag are covered in cards. Allow the bag to dry.
Place the bin bag over your head. Tie a piece of rope or ribbon around the waist to give it some shape. Paint your face with the symbol of your favourite suit in a pack of cards for extra effect.
Adjust the length of the bin bag dress with scissors. Since you can't wear any clothes underneath, it's advisable to keep the dress on the longer side.