Sudoku is a logic-placement puzzle, usually with numbers, that became popular in Japan in 1986 and went global in 2005, winning fans of every age.
The goal is to fill a 9 × 9 grid—divided into 3 × 3 sub-grids—with the digits 1 to 9, starting from a few numbers already placed on the board.
No digit may repeat in the same row, column or sub-grid.
This pastime challenges your problem-solving and logical-thinking skills and provides a mentally stimulating experience.
A Sudoku starts with several squares already filled—these are the “given numbers” or “clues”. Your task is to complete the grid by following the rules above. Use logic and deduction to determine the missing digits in each square. As you fill more cells, the puzzle becomes clearer (and tougher).
The best way to explain Sudoku solving is with a video, so we recommend the tutorial below.
There are many Sudoku variants based on size, difficulty or format. Here are five examples:
The term “Sudoku” comes from the Japanese su, meaning “number”, and doku, meaning “single”. Literally, Sudoku means “single numbers” or “numbers alone”. It’s fitting because each digit must be unique in its location on the grid. The game is a test of patience, logical thinking and concentration.
Despite its Japanese name, Sudoku’s roots trace back to 18th-century Europe, to the “Latin Square” invented by Swiss mathematician Leonhard Euler. But it was in Japan that the puzzle evolved into its modern form and got its present name in the 1980s.
Sudoku exploded internationally in 2005-2006, becoming a global phenomenon. Today it’s praised for improving concentration, logic and problem-solving skills, and its accessibility makes it a pastime for all ages.
Beginners should start with obvious squares, eliminate impossible candidates and focus on simpler digits before using advanced techniques.
It depends on the player’s experience and the puzzle’s difficulty: beginners may take an hour or more, while experts can finish easy Sudokus in minutes.
Yes—puzzles range from easy to extremely hard, allowing players to level up gradually.
An easy Sudoku has many initial clues, so you can solve it without complex logic techniques.
An extreme Sudoku offers very few starting clues and requires advanced logical methods to solve.
The rules require every row, column and sub-grid to contain all digits 1–9 without repetition, ensuring a single solution.