How to Play Sudoku
Master the basics in just a few minutes
What is Sudoku?
Sudoku is a logic-based number puzzle that has captivated millions of people worldwide. Despite using numbers, it requires no math skills. Instead, it challenges your ability to think logically and spot patterns. The name comes from the Japanese phrase "Sū ji wa dokushin ni kagiru," meaning "the digits must remain single."
The Grid
Every Sudoku puzzle uses a 9x9 grid containing 81 cells. This grid is further divided into nine 3x3 boxes (also called regions or blocks). When you start a puzzle, some cells already contain numbers. These are called givens or clues. Your job is to fill in the remaining empty cells.
- 81 total cells arranged in a 9x9 square
- 9 rows running horizontally
- 9 columns running vertically
- 9 boxes of 3x3 cells each
The Three Rules
Sudoku has only three constraints, and every puzzle follows them without exception.
Every Row
Each of the nine horizontal rows must contain all digits from 1 to 9. No number can appear twice in the same row.
Every Column
Each of the nine vertical columns must contain all digits from 1 to 9. No number can appear twice in the same column.
Every 3x3 Box
Each of the nine 3x3 boxes must contain all digits from 1 to 9. No number can appear twice in the same box.
The Goal
Your objective is straightforward: fill every empty cell with a number from 1 to 9 while following all three rules. A properly constructed Sudoku puzzle has exactly one solution, meaning there is only one correct way to complete it.
You cannot guess. Every number you place should be logically deducible from the numbers already on the grid. If you find yourself guessing, step back and look for clues you may have missed.
Getting Started
Scan the Grid
Start by looking at what numbers are already placed. Identify rows, columns, or boxes that are nearly complete.
Use Pencil Marks
Write small candidate numbers in cells to track possibilities. Eliminate candidates as you place numbers.
Start Easy
Begin with easier puzzles that have more givens. Build confidence before tackling harder difficulties.
Take Your Time
There is no time limit. Sudoku is about logic, not speed. Enjoy the process of working through the puzzle.
Ready to Start Solving?
Put your new knowledge to the test with our puzzle books.