A Short History of Sudoku: From an Indiana Architect to the World

Most people assume sudoku is an ancient Japanese puzzle. The truth is more interesting: the modern game was invented in Indiana, christened in Japan, and spread worldwide thanks to a retired judge from New Zealand.

1979: "Number Place" in New York

The modern sudoku first appeared in 1979 in Dell Pencil Puzzles and Word Games magazine, under the name Number Place. Its designer was Howard Garns, a retired architect from Indiana who contributed puzzles to Dell for many years. Garns added the 3 by 3 box rule to older Latin-square puzzles, and the game as we know it was complete — it just wasn't famous yet.

1984: Japan gives it a name

The puzzle reached Japan, where the publisher Nikoli introduced it in 1984 under a long Japanese title that was soon shortened to Su-Doku — roughly, "the numbers must appear singly." Nikoli refined the presentation (symmetrical givens, a limit on clue counts) and Japan's puzzle fans embraced it. The name stuck to the game permanently, even back in America.

2004: the world catches on

Retired New Zealand judge Wayne Gould discovered the puzzle in a Tokyo bookshop in 1997, spent years writing a program to generate sudokus, and in 2004 persuaded The Times of London to publish them. Within months, sudoku was a global fixture — newspapers worldwide carried daily puzzles, and the 9 by 9 grid became as recognisable as the crossword.

The gentle end of the scale

Fame brought an arms race of difficult variants. But sudoku's charm was never only about difficulty: with plenty of givens, the same rules make a calm, satisfying logic exercise where every step can be deduced, never guessed. That is the end of the scale we publish here — computer-generated, and computer-proven to have exactly one solution. Try a gentle one.