**Sudoku** (/suːˈdoʊkuː, -ˈdɒk-, sə-/; Japanese: 数独, romanized: *sūdoku*, lit. 'digit-single'; originally called **Number Place**)[1] is a logic-based,[2][3] combinatorial[4] number-placement puzzle. In classic Sudoku, the objective is to fill a 9 × 9 grid with digits so that each column, each row, and each of the nine 3 × 3 subgrids that compose the grid (also called "boxes", "blocks", or "regions") contain all of the digits from 1 to 9. The puzzle setter provides a partially completed grid, which for a well-posed puzzle has a single solution.

French newspapers featured variations of the Sudoku puzzles in the 19th century, and the puzzle has appeared since 1979 in puzzle books under the name Number Place.[5] However, the modern Sudoku only began to gain widespread popularity in 1986 when it was published by the Japanese puzzle company Nikoli under the name Sudoku, meaning "single number".[6] It first appeared in a U.S. newspaper, and then *The Times* (London), in 2004, thanks to the efforts of Wayne Gould, who devised a computer program to rapidly produce unique puzzles.