📋 Sudoku Rules Guide

Master the fundamentals of Sudoku so you can solve with confidence.

đŸŽ¯ Puzzle Objective

The goal of Sudoku is to fill a 9×9 grid with digits 1–9 so that each row, column, and 3×3 subgrid contains every number exactly once.

Example Grid

5
3
4
6
7
8
9
1
2
6
7
2
1
9
5
3
4
8
1
9
8
3
4
2
5
6
7

📏 Core Rules

📊

Row Rule

Each row must include the digits 1–9 with no repeats.

📈

Column Rule

Each column must also contain the digits 1–9 exactly once.

âŦœ

3×3 Subgrid Rule

Every 3×3 box must hold the digits 1–9 without duplication.

🎮 How to Play

1

Select a Cell

Click the square you want to fill. The selected cell will highlight.

2

Enter a Number

Use the number buttons or your keyboard to place digits 1–9.

3

Use Tools

Switch on notes to pencil in candidates, or tap the hint button when you're stuck.

4

Complete the Grid

Fill every cell correctly to finish the puzzle and celebrate the win!

⚠ī¸ Mistake Handling

❌

Mistake Limit

You can make up to three mistakes. Exceed the limit and the puzzle ends.

🔍

Error Highlighting

Incorrect entries are highlighted in red so you can fix them quickly.

↩ī¸

Undo Button

Use Undo to rewind your last move and recover from a mistake.

đŸŽ¯ Difficulty Levels

Easy

Perfect for newcomers with generous clues and straightforward logic.

Medium

A balanced experience that reinforces core solving skills.

Hard

Introduces advanced tactics like lone singles and hidden pairs.

Expert

Demands layered strategies and precise reasoning throughout.

Master

Extreme logic puzzles for veteran solvers seeking a serious challenge.

Extreme

Ultimate difficulty designed to test the limits of Sudoku knowledge.

📄 Page Overview

This rules guide from SudokuFun.org introduces every core aspect of Sudoku: the puzzle objective, row/column/box rules, step-by-step gameplay, mistake management, and difficulty tiers. With illustrated examples and approachable language, it's the ideal starting point for new players and a handy refresher for returning solvers.