So, you print out these sheets. There are instructions on how to make it all fancy on card stock and purchasing a container for all the cards, but the game is simple. You pick a small group of friends and hand out the white cards. Then, you choose a black card. Everyone picks the funniest, most clever answer out of his or her white card choices. Hilarity ensues.
You can see an example here. It explains visually what I cannot with words.