Sudoku is a simple but surprisingly engaging number puzzle enjoyed by people around the world. At first glance, a grid filled with numbers and empty squares might look complicated, but the rules are actually very easy to understand.
And despite all the numbers, you don’t need to be good at maths to play Sudoku. It’s a game of logic, observation and problem-solving.
Here’s everything you need to know to get started.
A standard Sudoku puzzle consists of a 9×9 grid containing 81 squares.
The grid is divided into:
Some numbers are already filled in when the puzzle begins. These numbers are your clues.
Your job is to fill in all the remaining empty squares using the numbers 1 through 9.
Sounds simple, right? There’s just one important catch.
Every number you enter must follow three rules:
1. Each row must contain the numbers 1–9 without repeating any number.
2. Each column must contain the numbers 1–9 without repeating any number.
3. Each 3×3 box must contain the numbers 1–9 without repeating any number.
That’s it.
You don’t need equations, calculations, or complicated formulas. Everything can be solved using the clues already on the board.
Start by looking for a row, column or 3×3 box that already contains several numbers.
Imagine a row contains:
1 · 2 · 3 · 4 · 5 · 6 · 7 · 9
Only one number from 1–9 is missing: 8.
That means the empty square must contain 8.
Of course, not every answer will be this obvious. As the puzzle becomes more difficult, you’ll need to compare rows, columns and boxes to eliminate numbers that cannot fit. That is where the pencil notes come into play. Pencil in a possible number in ONLY 2 cells in a square.
If you can see three cells in a square that could contain the number you are considering, then that is good too.
NOTE: Never pencil in more than 2 or 3 notes in a cell in a square. That is what creates the “clutter”!
When you first open a Sudoku puzzle, don’t try to solve it in a particular order.
Scan the entire board randomly instead.
Look for areas where only one or two numbers are missing. These are often the easiest places to start.
Every number you correctly place creates another clue, making it easier to solve other parts of the puzzle. Continue randomly until the puzzle is solved.
One of the most useful Sudoku techniques is elimination.
Suppose an empty square could potentially contain 3, 5 or 8.
If 3 already appears in the same row and 8 appears in the same column, neither number can be used.
That leaves only 5.
As you become more familiar with Sudoku, you’ll start making these deductions much more quickly.
Getting stuck is part of the fun.
If you can’t find an answer in one section, move somewhere else on the board.
Check another row.
Look at another column.
Explore a different 3×3 box.
Solving just one square somewhere else may give you the clue you need to continue. (The whirlpool effect)
Most importantly, avoid guessing. A Sudoku puzzle should be solved through careful placement, and one incorrect guess can cause confusion later.
If you’re playing Sudoku for the first time, start with an easy puzzle.
Easy puzzles generally give you more starting clues and allow you to practice the basic techniques without becoming overwhelmed.
Give your brain time to understand what you want it to do. Much like learning a piece of music on the piano.
Come back to the WEB PAGE before you try a harder puzzle.
There’s no rush. Sudoku is meant to be enjoyed at your own pace.
Now you know the rules:
Fill every row, column, and 3×3 box with the numbers 1–9 without repeating a number.
That’s all you need to get started.
Pick an easy puzzle, look for the obvious answers, and work your way through the grid one square at a time.
Ready to give it a try?
Play Sudoku →
