How to Play Sudoku
Sudoku is a logic-based number puzzle. No math required — just reasoning and pattern recognition.
The Basics
The Grid
A 9×9 grid divided into nine 3×3 boxes.
The Numbers
Use only digits 1 through 9.
The Goal
Fill every cell so each row, column, and 3×3 box contains 1–9 exactly once.
The Three Rules
Rows
Each row contains 1–9 with no repeats.
Columns
Each column contains 1–9 with no repeats.
Boxes
Each 3×3 box contains 1–9 with no repeats.
Strategies
Last Empty Cell
When a row, column, or box has one empty cell left, the missing number is the answer.
Single Candidate
If a cell can only hold one possible number after checking row, column, and box — that's it.
Pencil Marks
Note possible candidates in cells. Eliminate them as you fill in other numbers.
Hidden Singles
If a number can only go in one cell within a row, column, or box — it must go there.
Naked Pairs
Two cells in the same group with the same two candidates? Those numbers can be eliminated from the rest.
Tips
- Start with the most frequent given numbers
- Focus on nearly complete rows, columns, or boxes
- Never guess — Sudoku is pure logic
- Take breaks when stuck
- Practice daily to build pattern recognition