Janken

The smell of airconditioning. The feeling of moving at high speed, even though you’re standing still. If not dark when you look outside the window, then it’s blurry. You’re sitting in the subway. Or rather, hanging in your seat, as you are tired from your travels in Japan. In the seats across from you there are some lively high-schoolers. Hands are moving swiftly. What are they doing? They’re holding something. No. Wait. It just got passed to the next person. Is it a drink? It used to be. It’s trash now. Hands are still moving. Epiphany! They’re playing rock-paper-scissors, and the loser has to take with him the trash until he can bin it. Brilliant! Why don’t we do that at home? It makes the mundane lively. It strenghtens friendships. True story.

The game of rock-paper-scissors is known in Japan as janken (じゃん拳 janken). It is one of the ken games (literally, “fist” games). 拳 こぶし, pronounced “kobushi”, means “a fist”. The game follows the same rules as they are widely known. Rock “breaks” scissors, scissors “cuts” paper, and paper “covers” rock. You select one of the moves in the hopes of beating your adversary. Naturally, the terminology in Japan is in Japanese. It goes as follows. Rock is グウ guu, paper is パー paa, and scissors is チョキ choki. The game starts by holding out a closed fist. The players say: “最初はグウ。” (saisho ha guu, Starting with rock. Then they say: “じゃん けん ぽん!” (jan ken pon!), followed by throwing out their choice of move. If there’s a tie, both players say: “相子でしょ!” (aiko desho!, It seems like a tie!) And they keep going until someone wins. The game is commonly used to determine who is “it” in a game of tag, or who goes first in selecting teams. Or anything that needs settling, really. The Ishikawa Watanabe Laboratory settled the game of janken by building a robot with a 100% success rate. It’s success is due to a high-speed camera, and throwing out the winning move at the last moment against the much slower human. Check it out on video here.

Further reading:

“janken” In: Japan: An Illustrated Encyclopedia. Kodansha.

Janken (rock-paper-scissors) Robot with 100% winning rate. Ishikawa Watanabe Laboratory. [19 August 2014, https://www.youtube.com/watch?v=3nxjjztQKtY]

Japan’s Most Dangerous Game: Rock, Paper, Scissors. Hashi. [19 August 2014, http://www.tofugu.com/2012/07/06/japans-most-dangerous-game-rock-paper-scissors/]