A Short History of Sudoku

Latin squares came first

The mathematical seed of Sudoku is the Latin square, studied by the mathematician Leonhard Euler in the eighteenth century. A Latin square is a grid where each symbol appears once in every row and once in every column. Sudoku adds the extra rule about the 3 by 3 boxes, which is what gives it that satisfying bite.

The modern puzzle appears

The puzzle we play today took shape in the late 1970s, when an American puzzle maker published a version called Number Place. It had the familiar 9 by 9 grid, the boxes and the single solution. For a while it stayed a quiet corner of the puzzle world.

Japan gives it a name

In the 1980s the puzzle became popular in Japan, where a publisher gave it the name Sudoku, a shortening of a phrase that means the digits must be single. The name stuck, and the puzzle grew a devoted following there over the next two decades.

A worldwide craze

In 2004 and 2005 Sudoku exploded across the world after newspapers began printing a daily puzzle. Almost overnight it appeared in papers, books and early mobile apps everywhere. What made it spread was its simplicity. The rules fit in one sentence, no language or math background is needed, and every puzzle has a clean, provable answer.

Sudoku today

Now Sudoku lives mostly on phones and in browsers, with daily challenges, hints, notes and leaderboards. Designers also experiment with new looks and rules. Shapedoku is part of that tradition, keeping the classic logic while swapping the numbers for nine glowing shapes that are easier to read and kinder to colorblind players.

The puzzle has traveled a long way from a mathematician's grid to your pocket. The logic, though, is exactly the same one people have enjoyed for decades. Play a piece of that history in Shapedoku today.