I'm not sure why, but I was thinking about the game of rock, paper, scissors. I understand that scissors cut paper, and rock blunts scissors, but how does paper defeat rock? If I throw a rock at someone it'll hurt just as much regardless of whether I've gift-wrapped it. I've tried Wikipedia, who have a needlessly extensive article on the subject, but no explanation as to why the three items were chosen. So, does anyone know, or even have a good guess? And how could paper defeat rock?