How to Play Sudoku

A classic number puzzle — pure logic, no math required

Play it here: https://sudoku.game

Sudoku looks intimidating at first because it’s full of numbers, but don’t let that fool you — there’s no arithmetic involved at all. It’s purely a logic puzzle, and it’s wonderful, quiet practice for careful thinking.

What You’ll Need

• A computer, laptop, or tablet with an internet connection
• No download or account needed — it’s completely free
• 15-30 minutes of quiet time, depending on the difficulty you choose

The Grid
A Sudoku puzzle is a 9×9 grid, divided into nine smaller 3×3 boxes (marked with bold lines). Some squares already have numbers filled in — those are your clues.

The One Rule
Everything in Sudoku comes down to a single rule, applied three different ways.

In other words: the numbers 1 through 9 must each appear exactly once in every row, every column, and every 3×3 box. That’s the entire rulebook.

Filling In a Number

1. Click on any empty square. It will highlight to show it’s selected.
2. Click the number you believe belongs there. It fills right in.
3. Changed your mind? Click the square again and pick a different number.
4. Keep working through the puzzle — use the row, column, and box rule to figure out what CAN’T go in a square, which often reveals what CAN.

Tips for Success

• Start with rows, columns, or boxes that already have the most numbers filled in — they’re easiest to solve first.
• Choose “Easy” from the Difficulty menu when starting out — it gives you more starting clues.
• If you get stuck, look at one number at a time (“where can every 7 go?”) rather than one square at a time.
• There’s no penalty for taking breaks — close the tab and your unfinished puzzle simply waits for you.

If Something Goes Wrong

• Not sure if a number is correct? Many versions highlight mistakes in red automatically — check your game’s Options.
• Puzzle feels too hard? Use the Difficulty menu to choose an easier level with more starting numbers.
• Want a hint? Look for a “Help” or “Hint” button — most free Sudoku sites offer one.

Sudoku is one of the very best puzzles for practicing focused, step-by-step logical thinking — and every completed puzzle is a real, satisfying accomplishment.