Who Invented Sudoku?

Sudoku was most likely invented by Howard Garns, an American architect and freelance puzzle designer, who published a version called Number Place in Dell Pencil Puzzles & Word Games magazine in May 1979. Garns died in 1989, before the puzzle reached global fame. If you want to test your own sudoku skills, you can play free sudoku online at internetsudoku.net.

The Origin: Number Place (1979)

The puzzle now known as sudoku first appeared in the United States under the name Number Place. In 1979, Dell Magazines — a New York publisher specialising in puzzles and word games — printed it in their Pencil Puzzles & Word Games magazine. The rules were identical to modern sudoku: fill a 9×9 grid so that every row, every column, and every 3×3 box contains the digits 1 through 9 exactly once, using pre-filled clues as starting points.

The puzzle appeared without a credited author, which is standard practice for Dell puzzle magazines. This anonymity is part of why the question of who invented sudoku remains slightly contested today.

Howard Garns — The Most Likely Inventor

Research by puzzle historian Will Shortz (crossword editor at The New York Times) identified Howard Garns as the almost-certain creator of Number Place. Garns was a 74-year-old retired architect from Indianapolis, Indiana, who contributed regularly to Dell puzzle publications under his own name. His name appears in the contributor list of virtually every issue of Dell Pencil Puzzles & Word Games that contained a Number Place puzzle — and is absent from issues that did not.

Garns designed puzzles as a hobby after retiring from architecture. He lived long enough to see Number Place become a fixture in Dell's monthly magazine, but he died in August 1989 at the age of 84 — more than a decade before his invention became one of the world's most popular puzzles.

How Japan Adopted and Renamed the Puzzle

In 1984, the Japanese puzzle publisher Nikoli encountered Number Place in Dell Magazine and introduced it to Japan. The Japanese name they coined — Sūji wa dokushin ni kagiru (数字は独身に限る), meaning "the digits must remain single" — was shortened to Sudoku (数独) for practical use.

Nikoli made two refinements to the original puzzle that are now considered standard: they limited the number of given digits to 32 (to ensure consistent difficulty) and required that the given digits be placed symmetrically. These design conventions became the global standard even though Western publishers sometimes ignore the symmetry rule.

By the mid-1980s, sudoku puzzles were appearing regularly in Japanese newspapers and puzzle magazines. The game grew steadily in Japan for two decades before it crossed back to the English-speaking world.

The Return to the West (2004)

Sudoku's global explosion began in 2004, largely through Wayne Gould, a retired Hong Kong judge from New Zealand. Gould had discovered the puzzle in Japan in 1997 and spent six years writing a computer program to generate fresh sudoku grids automatically. In 2004 he convinced The Times of London to publish daily sudoku puzzles — and the paper's decision triggered a rapid wave of adoption across UK newspapers, then US papers, then the world.

Within two years of The Times' first sudoku, the puzzle appeared in hundreds of newspapers worldwide. Book publishers rushed out sudoku collections. The puzzle arrived online, first as printed-grid downloads, then as interactive browser games — and eventually on mobile apps, where it remains one of the most downloaded puzzle categories.

Why Sudoku Has No Single "Inventor"

The full story shows sudoku emerging through several hands across different continents:

The mathematical ancestor of sudoku — Latin squares — goes back even further. Swiss mathematician Leonhard Euler described their properties in 1783, though Euler's Latin squares do not include the 3×3 box constraint that defines sudoku's distinctive difficulty.

Frequently Asked Questions

Who invented sudoku?
Howard Garns, an American retired architect and freelance puzzle designer, is credited with creating Number Place — the puzzle later renamed sudoku — first published in Dell Magazines in 1979.
What was sudoku originally called?
The original puzzle was called Number Place, published in the American magazine Dell Pencil Puzzles & Word Games. The Japanese name Sudoku (数独) was coined by the publisher Nikoli in 1984.
Did Japan invent sudoku?
No. Sudoku was invented in the United States and first published in 1979. Japan's puzzle publisher Nikoli discovered it in 1984, gave it the name Sudoku, refined the rules, and built its first mass audience — but the original puzzle was American.
When did sudoku become popular worldwide?
Sudoku went global in 2004 when retired New Zealand judge Wayne Gould persuaded The Times of London to publish daily puzzles. Within two years, the game had spread to newspapers and bookshelves worldwide.