Sudoku
The rules
How to play
- 01
The grid
Sudoku is played on a 9×9 grid divided into nine 3×3 boxes. Some cells arrive pre-filled — these are your clues.
- 02
Rows
Each row must contain the digits 1 through 9 exactly once. No digit ever repeats across a row.
- 03
Columns
The same rule applies vertically: every column holds each digit exactly once, top to bottom.
- 04
Boxes
Every 3×3 box also contains all nine digits exactly once. The three rules together define the whole game.
- 05
One solution
A proper Sudoku has exactly one solution, and you can always reach it with pure logic. Guessing is never required.
Play smarter
Six habits of fast solvers
Scan for singles
Look for rows, columns, or boxes missing just one digit — the fastest wins on the board.
Use pencil marks
Note candidate digits in empty cells to keep track of what remains possible.
Find naked pairs
Two cells sharing the same two candidates eliminate those digits from their neighbours.
Check intersections
Where a row or column crosses a box, one often constrains the other.
One digit at a time
Sweep the board for a single digit and place every instance you can before moving on.
Never guess
If you feel stuck, a logical deduction is still waiting somewhere. Find the pattern.
Watch & learn
Two minutes to mastery
From the Intel desk
Reading for the curious
Sudoku Puzzle: A Complete Beginner's Guide to Number Placement
Learn how to solve Sudoku puzzles from scratch. Master the basic rules, follow our visual step-by-step tutorial, and discover essential strategies that will transform you from confused beginner to confident solver.
Logic Puzzles for Kids: How Puzzles Build Math-Ready Minds (Ages 6-8)
Research-backed guide for parents on how logic puzzles develop working memory, spatial reasoning, and problem-solving skills in children ages 6-8. Includes age-appropriate puzzle recommendations and practical tips.
Sudoku Strategies: Essential Techniques Beyond the Basics
Master Sudoku with naked pairs, hidden singles, box-line reduction, and X-wing techniques. Solve any puzzle without guessing—pure logic only.
Keep going
Where to next
Fresh every day
The Daily Sudoku
One shared puzzle for everyone, every day. Build a streak and compare your time.
Go deeper
Rules & strategy guide
From basic scanning to naked pairs — the complete written guide with examples.
Beyond the grid
Explore all puzzles
Nonograms, Kakuro, Slitherlink and fifteen more logic games await.