A short history of Sudoku
Sudoku has a Japanese name, but its story passes through Switzerland, France, the United States, Japan, New Zealand and Britain.
Old ideas
In the 1700s the Swiss mathematician Leonhard Euler studied "Latin squares" — grids where each symbol appears once in every row and column. Sudoku adds boxes to that idea. In the 1890s, French newspapers printed number puzzles that were close cousins of today's Sudoku.
Number Place
The modern puzzle first appeared in 1979 in Dell Pencil Puzzles and Word Games, an American magazine. It was called Number Place and is generally credited to Howard Garns, a retired architect from Indiana.
A new name in Japan
In 1984 the Japanese puzzle company Nikoli introduced the puzzle to Japan with a long name meaning roughly "the digits must be single." It was shortened to Sudoku — "single number." Nikoli also popularized the idea that a good puzzle should have one answer and be solvable by logic alone.
The world catches on
Wayne Gould, a retired judge from New Zealand, found Sudoku in a Tokyo bookshop and spent years writing a computer program to create puzzles. The Times of London began printing his puzzles in November 2004. Within months, newspapers around the world were carrying Sudoku, and 2005 became the year of the Sudoku craze, with books, TV shows and championships.
Why it lasts
Sudoku needs no special knowledge and no language, only a pencil and some patience. Many people enjoy it as a daily habit to keep the mind active.
Calm Sudoku
Calm Sudoku keeps the Nikoli tradition: every puzzle has one answer and can be solved step by step. It adds big numbers, optional red mistake marks, notes, and hints that explain their reasoning.
Learn the rules in how to play, or read our tips.