Sudoku

Rules of Sudoku

The goal of Sudoku is to fill a grid with numbers so that every row, column, and sub-grid contains all of the digits from 1 up to the grid size, with no repetitions.

• Rows: Each row must contain the numbers 1-9 exactly once.
• Columns: Each column must contain the numbers 1-9 exactly once.
• 3x3 Boxes: Each 3x3 box (or "region") must contain the numbers 1-9 exactly once.

The puzzle starts with some cells already filled in. These are your clues. You must use logic to fill in the remaining cells according to the rules.

In addition to the classic 9x9 Sudoku, this app also offers smaller board sizes for beginners or quick play:

• 3x3 Sudoku: A 3x3 grid using numbers 1-3. Each row and column must contain 1, 2, and 3 exactly once. Since the "boxes" are 1x1 (single cells), the main constraints are just the rows and columns. This is perfect for learning the basic concepts of Sudoku without overwhelming complexity.
• 6x6 Sudoku: A 6x6 grid using numbers 1-6. The boxes are 2x2 rectangles. Each row and column must contain 1-6 exactly once and the 2x2 box must contain only 4 different numbers from 1-6. This provides a middle ground between the simplicity of 3x3 and the challenge of 9x9, helping players build logical reasoning skills.

These smaller variants follow the same core rules as 9x9 Sudoku but scaled down, making them excellent for educational purposes or when you want a faster puzzle-solving experience.

History of Sudoku

While its roots trace back to "Latin Squares" in 18th-century Switzerland, the modern Sudoku was first published in the U.S. in 1979 as "Number Place." It gained massive popularity in Japan in the 1980s, where it was given the name Sudoku (meaning "single number"). A retired judge from New Zealand, Wayne Gould, was instrumental in its global explosion after he created a computer program to generate puzzles and convinced the newspaper "The Times" in London to publish them in 2004.