Rock, scissors, paper (also known as rock, paper, scissors, or paper, rock, scissors, etc.) is not just some kids game. It is a serious game. There is even a world championship for it every year in Toronto. Check out the World RPS website where you will find the official rules, strategies, and information on tournaments, among other things.
Rock, scissors, paper is a very popular game in Korea. Children often play it in their breaks,, or when divvying up snacks or what ever. It is a great way to solve disputes in the classroom. There is never any arguement over the results of a rock, scissors, paper game. The obsession isn't just with the kids, either. Even the US legal system sometimes employs this little problem solver. Imagine that! Other big disputes have also been solve with the little game (found on Wikipedia's rock, paper, scissors page):
One high-profile strategic opinion came in 2005 from Alice Maclean, age 11. When rival auction houses Christie's and Sotheby's agreed to play rock-paper-scissors to determine the rights to a highly valuable art collection, Maclean's father Nicholas, a Christie's employee, asked her for advice. As later told to reporters, her strategy was summed up thus: "Everybody knows you always start with scissors. Rock is way too obvious, and scissors beats paper." (Christie's won, with scissors.)
Try your luck with the online rock, paper, scissors game.
For a little rock, scissors, paper humor: Rock, Paper, Saddam