Learn How to Play Sudoku 🧩
A clear step-by-step guide to rules, solving techniques, and logic with two interactive practice drills.
The 3 Golden Rules of Sudoku
Sudoku is played on a 9×9 grid divided into nine smaller 3×3 boxes. It requires no math or arithmetic — just observation and pure logic!
Every Row
Each horizontal row must contain the numbers 1 through 9 exactly once.
Every Column
Each vertical column must contain the numbers 1 through 9 exactly once.
Every 3×3 Box
Each of the nine 3×3 boxes must contain the numbers 1 through 9 exactly once.
Golden Rule: No number can ever repeat within the same row, column, or 3×3 box!
Where must the number 8 go?
Cross-hatching is the most essential technique in Sudoku. Look at the three boxes below:
- Box 1 already has an 8 in row 1. Therefore, no other cell in row 1 can be 8.
- Box 2 has an 8 in row 2. Therefore, no other cell in row 2 can be 8.
- Your goal: In Box 3 (on the right), rows 1 and 2 are blocked. Which cell must contain the 8?
Tap the yellow cell marked «?», then select 8 on the numpad below:
Solve the Last 4 Cells
Here is a real Sudoku board where 77 of 81 cells are already solved! Only 4 yellow cells remain.
Tap any yellow cell. Notice how its row, column, and 3×3 box light up to help you spot missing digits. Pick the correct number from the keypad:
3 Secrets to Solving Sudoku Faster
- Start with the most frequent digits: If a puzzle already has five or six 7s placed, you can easily pin down the rest using cross-hatching.
- Use pencil marks ✏️: On WordKing you can switch on pencil notes to jot down candidates in uncertain cells.
- Never guess: A single wrong guess spreads errors throughout the board. If you're stuck, switch focus to another row or box.
Congratulations! You're Ready for Sudoku 🚀
Now that you've practiced the fundamentals, start with an easy puzzle and experience the joy of solving!