Japan's Most Dangerous Game: Rock, Paper, Scissors 最初はグー、じゃんけんぽん！

If you've ever needed help making a small decision like who gets the last piece of pizza or who gets to ride shotgun, you're probably more than familiar with the game of rock, paper, scissors.

But you might not know how big rock, paper, scissors is in Japan. Turns out that rock, paper, scissors – or as it's known in Japan, janken – was big in Japan before anybody in the West had ever even heard of it.

Like kanji, fireworks, and General Tsao's chicken¹, rock, paper, scissors was actually created in China. The game was created around the time of Christ, but stayed in China for hundreds of years. It wasn't until the 1700s that it made its way over to Japan.

The rest, as they say, is history. Janken, in the ensuing years, became incredibly popular in Japan and today, pretty much everybody in Japan knows how to play. You could walk up to any child in Japan and he/she would be immediately ready to throw down in a game of janken.

How to Play

Janken is played pretty similarly to the way most people play rock, paper, scissors in the US: you use one of three moves to beat your opponent. Rock breaks scissors, scissors cuts paper, and paper covers rock.

Obviously in Japan though, they use different terminology. Here's a handy table:

English	Romaji	Japanese
Rock	Guu	guu （グー）
Paper	Paa	paa （パー）
Scissors	Choki	choki （チョキ）

The differences don't stop there. There's a whole special ritual to janken that's a little different than what I'm used to in the US.

1. Both players start by saying "Saisho wa guu" (saishohagu 最初（さいしょ）はぐう) or "Starting with rock," and holding out a closed fist.
2. Each says "janken pon!" and throw out their move, whether it's rock, paper, or scissors.
3. If there's a tie (both players choose the same move), both players say "Aiko desho!" (aiko 相子（あいこ）相子), or "It seems like a tie!" and keep going in rapid-fire succession until somebody finally wins. But it doesn't stop there. There are tons of variants to janken, some more violent than others:

Make no mistake though: janken isn't just used for schoolyard disputes. Virtually everybody in Japan plays janken to solve disputes or make decisions.

Pop group AKB48 has held janken tournaments to determine which of the young ladies appear on the group's next single. Competition is fierce, and the tournaments can run for several hours.

Janken was once even used in an international, multimillion dollar art deal.

The Most Expensive Game of Rock, Paper, Scissors

Janken isn't just used by the Japanese to see who pays for the beer or whose turn it is to clean the dishes; it can also be used for expensive, high-stakes decisions.

In 2005, a Japanese businessman decided to auction off his art collection which included masterpieces from renowned European artists like Cézanne, Picasso, and van Gogh.

But he ran into a bit of a snag when it came time to decide which of the world's two most famous auction houses, Christie's and Sotheby's, would get the rights to auction off his magnificent collection.

So how did this businessman make his decision? He made the two auction houses compete in a game of janken.

The two auction houses spent a weekend strategizing, planning their one, critical move; and on Monday, the competition took place. The New York Times paints a picture of the scene:

Instead of the usual method of playing the game with the hands, the teams were given a form explaining the rules. They were then asked to write one word in Japanese – rock, paper or scissors – on the paper.

After each house had entered its decision, a Maspro manager looked at the choices. Christie's was the winner: scissors beat paper.

"We were told immediately and then asked to go downstairs to another room and wait, while the forms went off to headquarters to be approved," Mr. Rendell said. He described the atmosphere in the room as "difficult," saying both sides were forced to "make small talk."

But while janken has served as a cornerstone of the decision-making process for centuries, that era may soon be coming to an end.

Has Japan Solved Rock, Paper, Scissors?

A Japanese university has recently invented a robot that beats humans every time in rock, paper, scissors. That's right, it has a 100% winrate. Say what?

How does it do it? It's pretty simple: the robot uses a camera to quickly read what its opponent's move is going to be, and reacts at the last possible second.

What happens when two of these robots play against each other? An infinite tie? Would the universe implode? Nobody can know for sure.

But I can say this: until somebody makes a portable janken robot available to the masses, janken will remain a cultural staple in Japan.

Just remember, the next time that you're challenged to a game of janken to decide who buys the next round, don't pick rock.