Rock Paper Scissors AI
Play →

Two thousand years of throws

The history of rock paper scissors

Invented in China, perfected in Japan, adopted by the world. The three-hand standoff is one of the oldest decision rituals still in daily use, and it has settled everything from playground disputes to a $20 million auction.

  1. ~200 BC · China

    Texts from the Han dynasty describe shoushiling, a hand-throwing standoff game, the earliest known ancestor.

  2. 1600s · Japan

    Sansukumi-ken ("three who fear one another") hand games flourish, including mushi-ken: frog beats slug, slug beats snake, snake beats frog.

  3. 1700s–1800s · Japan

    Jan-ken emerges with the modern three hands, rock (guu), scissors (choki) and paper (paa), and becomes the definitive version.

  4. 1920s · Europe

    First clear Western descriptions: a 1924 letter in The Times, "chi-fou-mi" explained in France in 1927. The game crosses into Western playgrounds.

  5. 1930s–1950s · USA

    American children's handbooks teach "rochambeau". The game becomes the world's default fair-decision ritual.

  6. 2000s · Worldwide

    World championships, cash-prize leagues, and the famous 2005 Christie's vs Sotheby's auction decided by a single throw.

  7. Today · Your browser

    Machine opponents flip the game: pattern-reading AIs beat humans not with a stronger hand, but with prediction.

From jan-ken to janken bots

The Japanese version matters because it fixed the abstraction. Earlier sansukumi-ken games used creatures (frog, slug, snake), but jan-ken's rock, paper and scissors are pure symbols with a perfectly balanced cycle, which is exactly why the game travelled so well. Every culture could adopt the same three hands and the same chant cadence.

The modern chapter belongs to machines. In 2013 the University of Tokyo demonstrated a robot hand that won 100% of games, by watching the human wrist with a high-speed camera and reacting in one millisecond, which is cheating, just very fast cheating. The honest machine approach is prediction: learning a player's habits and countering the likely next throw. That is the branch of history you can play against here, details on how the AI works.

History FAQ

When was rock paper scissors invented?

The earliest known ancestor, the Chinese hand game shoushiling, is described in texts from around the Han dynasty (206 BC – 220 AD). The modern rock-paper-scissors form was standardised in Japan as jan-ken in the 17th–19th centuries, and spread to the West in the early 20th century.

Where was rock paper scissors invented?

China first (as shoushiling, a "finger-guessing" game), then Japan, where the three-hand rock/paper/scissors version, jan-ken, took its modern shape. The Japanese version is the direct ancestor of the game played worldwide today.

What did people play before rock paper scissors?

Sansukumi-ken games, Japanese hand games built on a three-way standoff. The most famous pre-RPS version was mushi-ken: frog beats slug, slug beats snake, snake beats frog, with hand signs for each creature.

When did rock paper scissors reach Europe and America?

Written Western references appear in the 1920s. A 1924 letter in The Times described it as a Mediterranean game, and by 1927 the French children's magazine La Vie au patronage explained "chi-fou-mi" in detail. It became a global playground standard within a few decades.

Is rock paper scissors used for real decisions?

Constantly, from playgrounds to boardrooms. In 2005 a Japanese electronics company famously had Christie's and Sotheby's play rock paper scissors for the right to auction its $20 million art collection. Christie's threw scissors and won.