History of Sudoku

It reached a worldwide audience in 2004, when a former Hong Kong judge, Wayne Gould, persuaded The Times of London to run puzzles made by his computer program. Earlier French newspaper puzzles shared some of its ideas, but they were not the same puzzle. The sources disagree on a few details, which this page points out.

What puzzles came before Sudoku?

Number puzzles built on grids appeared in French newspapers in the late nineteenth century. Puzzle setters there experimented with removing numbers from magic squares, where every row and column adds up to the same total. On 19 November 1892 the Paris daily Le Siècle printed a partly filled 9×9 magic square divided into 3×3 sub-squares. It was not a Sudoku, because it used two-digit numbers and needed arithmetic to solve. On 6 July 1895 its rival La France printed a version it called a “carré magique diabolique”, which asked for the digits 1 to 9 in each row, each column and each broken diagonal. The 3×3 sub-squares were not marked, although they also turned out to hold the digits 1 to 9. Such puzzles appeared weekly in several French papers for about a decade and faded around the First World War [1].

These puzzles show that the ingredients existed early. Whether the American designer of the modern puzzle knew of them is, according to the source used here, unclear [1]. A deeper mathematical ancestor, the Latin square, is covered on the page about Latin squares and the math behind Sudoku.

Where did Number Place come from?

The modern form first appeared in 1979 in puzzle books from Dell Magazines, under the title Number Place. These are described as the earliest known examples of modern Sudoku. The designer is thought to be Howard Garns, a 74-year-old retired architect and freelance puzzle constructor from Connersville, Indiana, who worked anonymously and died in 1989, before the puzzle became a worldwide craze [1].

The attribution rests on circumstantial evidence. In 2005 the New York Times puzzle editor Will Shortz noticed that Garns’s name appeared in the list of contributors in every issue of Dell Pencil Puzzles and Word Games that contained Number Place, and in none that did not [1]. That is a strong clue and not a signed credit, which is why the source says “most likely”.

How did it become Sudoku in Japan?

According to the same source, Maki Kaji, president of the Japanese puzzle company Nikoli, introduced the puzzle in Nikoli’s magazine Monthly Nikolist in April 1984, under a long Japanese title that can be translated as “the digits must be single”. A 2007 BBC article, as summarized there, says Kaji had come across the puzzle in Dell’s books. The short name sudoku was made by taking the first character of each of the two compound words in the title, so that “su” means number and “doku” means single [1]. Nikoli says it holds the trademark rights to the name “sudoku” in Japan, and some other Japanese publishers use the name Number Place instead [1].

Nikoli is also credited with making the puzzle more disciplined. Its own website, as reported by a Canadian newspaper, says Nikoli improved Number Place by arranging the given numbers symmetrically on the board, so that they form a pattern [2]. For roughly a decade, handmade Nikoli puzzles dominated in Japan [2].

How did it reach the rest of the world?

In 1997 Wayne Gould, a recently retired Hong Kong judge, saw a Sudoku book in a Tokyo bookshop. Over the following six years he wrote a computer program that produced puzzles and rated their difficulty [1]. He then offered the puzzles to newspapers for free, asking only that they credit him and link to his website [1].

• September 2004: The Conway Daily Sun, of North Conway, New Hampshire, printed a Gould puzzle, the first newspaper outside Japan to publish a Sudoku [1].
• 12 November 2004: The Times of London launched it, calling it Su Doku. The first letter about it appeared the next day, from a reader who said it had made him miss his stop on the Underground [1].
• 2005: The Times began running easy and difficult puzzles side by side on 20 June. A British pay-television channel broadcast a live Sudoku show on 1 July, and the Radio Times printed a weekly 16×16 “Super Sudoku” from 2 August [1].
• 2006: By mid-year nearly every major United States newspaper carried a daily Sudoku, and the World Puzzle Federation began an annual World Sudoku Championship series [1].
• 2008: Within two weeks of Apple opening its App Store on 11 July, nearly thirty Sudoku games were already in it [1].

Where do the sources disagree?

A careful history has to admit a few loose ends.

• The date of the invention. The Dell publication is dated 1979 in the encyclopedia article used here [1]. A 2006 column by the puzzle writer Ed Pegg Jr. in The Mathematica Journal says Garns invented the puzzle in 1978 [3]. These are compatible if 1978 is the invention and 1979 the publication, but the sources do not say so.
• The date of the name. The encyclopedia article’s introduction ties the short name “sudoku” to 1986, while its history section places the first Nikoli printing in April 1984 and credits Kaji with the abbreviation without a year [1]. This page therefore dates the Nikoli publication to 1984 and does not commit to a year for the short name.
• Who made it. “Most likely Howard Garns” is as far as the sources go [1].

Readers who want first-hand material should start with the references cited in the encyclopedia article. They include a 2005 Mathematical Association of America column by Ed Pegg Jr., a 2007 BBC feature on Maki Kaji and a 2006 piece in The Times about the French ancestors. This page did not open those documents.

What does this history mean for this site?

This site’s puzzles are not copied from Nikoli, Dell or any newspaper. They are generated by the site’s own program, which removes clues in random order and keeps a removal only if the puzzle stays uniquely solvable at its level. It does not impose the symmetric layout of givens that Nikoli popularized, so the puzzles here look different from hand-made ones. The method is described in how puzzles are generated and verified unique, and the guide on how difficulty is graded explains why the levels follow technique and not clue count. To try the puzzle yourself, pick a level on the home page. The history hub lists the other three history pages.

Sources

1. “Sudoku.” Wikipedia. https://en.wikipedia.org/wiki/Sudoku. Accessed 22 October 2026.
2. “The crack cocaine of games.” The Globe and Mail. https://www.theglobeandmail.com/arts/the-crack-cocaine-of-games/article18242760. Accessed 22 October 2026. Publication date not shown in the copy read.
3. Ed Pegg Jr. “Beyond Sudoku: Ripple Effect.” The Mathematica Journal 10(2), 2006, Wolfram Library Archive entry. https://library.wolfram.com/infocenter/Articles/6405/. Accessed 22 October 2026.