How to Play Sudoku? (Rules Explained)
The goal of Sudoku is simple: fill a 9×9 grid with numbers from 1 to 9 while following all the rules at the same time.
In this guide, you will learn how to play Sudoku step by step. We explain the basic rules, show how the 9×9 grid works, highlight common mistakes, and share beginner-friendly tips to help you solve Sudoku puzzles with confidence.
Sudoku Board and Basic Logic (9×9)
Classic Sudoku uses a 9×9 grid divided into nine 3×3 boxes. Some numbers are given at the start and cannot be changed. Your task is to fill the remaining cells so that all rules are respected.
The 3 Golden Sudoku Rules
- Row: Each row must contain the numbers 1–9 exactly once. No number can repeat within the same row.
- Column: Each column must contain the numbers 1–9 exactly once. No number can repeat within the same column.
- 3×3 Box: Each 3×3 box must contain the numbers 1–9 exactly once. This is the most commonly missed rule.
See the Rule in Action: Rows & Columns
Watch this short demo to understand how row and column rules work visually. You can reset and replay it anytime.
Bir hücreye tıkla ve dene.
The 3×3 Box Rule (Most Common Mistake)
This demo shows why repeating a number inside a 3×3 box breaks the Sudoku rules.
Bir hücreye tıkla ve dene.
What Is an Invalid Move in Sudoku?
A move is invalid if the number you place already exists in the same row, column, or 3×3 box. Sudoku Together highlights these conflicts so you can quickly spot and fix mistakes.
Sudoku Tips for Beginners
- Scanning: Scan rows, columns, and boxes to find cells with only one possible number left.
- Single Candidate: If only one number fits in a cell, that number must be placed there.
- Single Position: If a number can go in only one cell within a row, column, or box, place it there.