What are the rules of sudoku?

Fill the 9×9 grid so every row, every column and every 3×3 box contains the digits 1 to 9 once each. No row, column or box may repeat a number. A proper puzzle has one solution, reachable by logic alone.

Can I print the sudoku rules?

Yes. This page comes with a free one-page rules sheet and a fuller PDF booklet you can print or save. No sign-up, no watermark — just hit print or download.

No. Sudoku uses the digits 1 to 9, but you never add, subtract or count. It's a pure logic puzzle — you could swap the numbers for nine letters or symbols and it would play exactly the same.

How many rules does sudoku have?

Just three: each digit 1 to 9 must appear once per row, once per column and once per 3×3 box. Everything else — every solving technique — is built on top of those three simple rules.

Sudoku Rules — The Free Printable Guide

Sudoku has just three rules, and you can learn them in under a minute. Fill the 9×9 grid so every row, every column and every 3×3 box holds the digits 1 to 9 once each. That's the whole game — no maths, no guessing, just logic.

This page gives you the rules at a glance plus a printable rules sheet and a fuller PDF booklet. Below it, pick the level that fits you and grab the matching cheat-sheet.

The three rules of Sudoku

A classic sudoku is a 9×9 grid split into nine 3×3 boxes. You start with some numbers already filled in. Your job is to complete the grid so that:

Every row contains the digits 1 to 9, with no repeats.
Every column contains the digits 1 to 9, with no repeats.
Every 3×3 box contains the digits 1 to 9, with no repeats.

That's it. A proper sudoku always has exactly one solution, and you can reach it by pure logic — you never have to guess.

Each row must hold the digits 1 to 9 exactly once — no number can repeat along the line.

The same rule runs top to bottom: every column carries 1 to 9 with no repeats.

Every 3×3 box must also hold all nine digits, so each number appears once per box.

Pick your level

Sudoku Rules for Beginners

Brand new to sudoku? Start here for the rules explained simply, step by step, plus a beginner cheat-sheet.

Sudoku Cheat Sheet — Every Intermediate Technique

Solving steadily and want to go faster? The cheat sheet puts every intermediate technique on one printable page.

Advanced Sudoku Techniques — Printable Reference

Hunting the hardest patterns? The expert sheet covers X-Wing, Swordfish, XY-Wing and coloring at a glance.

What's inside the printable

Two free downloads. The one-page rules sheet shows the three rules with a worked grid for each — print it and keep it beside you while you solve. The full rules booklet is a multi-page PDF that adds the first solving moves and a glossary of terms. Both are branded, ad-free and need no sign-up. Save them or send them straight to your printer.

Want the full lessons?

These pages are quick printable references. For the full, step-by-step teaching of any rule or technique — with interactive grids and worked walkthroughs — head to Sudoku247 Wiki. We keep it short here so you can print and go; the wiki goes deep.

Sudoku rules →

Frequently asked questions

What are the rules of sudoku?: Fill the 9×9 grid so every row, every column and every 3×3 box contains the digits 1 to 9 once each. No row, column or box may repeat a number. A proper puzzle has one solution, reachable by logic alone.
Can I print the sudoku rules?: Yes. This page comes with a free one-page rules sheet and a fuller PDF booklet you can print or save. No sign-up, no watermark — just hit print or download.
Is sudoku maths?: No. Sudoku uses the digits 1 to 9, but you never add, subtract or count. It's a pure logic puzzle — you could swap the numbers for nine letters or symbols and it would play exactly the same.
How many rules does sudoku have?: Just three: each digit 1 to 9 must appear once per row, once per column and once per 3×3 box. Everything else — every solving technique — is built on top of those three simple rules.