Free downloadable resource

Sudoku Rules Cheat Sheet — Free PDF Download

Know the Rules. Solve with Confidence.

Sudoku has three rules. Just three. But when you’re staring at 81 cells and trying to remember whether you’ve checked the row, the column, or the box, it helps to have those rules right in front of you.

That’s what this cheat sheet is for.

We made a clean, printable one-page reference that covers everything you need to remember while solving: the three rules of Sudoku, how the grid works, key terminology, and a handful of quick-start tips that’ll save you time on every puzzle.

What’s in the PDF

The Sudoku Rules Cheat Sheet includes:

• The 3 fundamental rules — rows, columns, and 3×3 boxes, explained clearly with no ambiguity.
• Grid anatomy — a visual breakdown of cells, rows, columns, boxes, and givens, so you always know what you’re looking at.
• Quick-start tips — five practical habits that make your first scan of any puzzle more efficient.
• Key terminology — a glossary of terms like “naked single,” “hidden single,” “candidate,” and “elimination” so you can follow any strategy guide without getting lost.
• Next steps — where to go once you’ve internalized the basics (strategies, printable puzzles, and more).

It’s designed to be pinned next to your desk, tucked into a puzzle book, or kept on your tablet for quick reference. One page, front and back — everything you need, nothing you don’t.

Who This Is For

If you’re new to Sudoku, this cheat sheet is your foundation. The rules are simple, but having them written down — especially the grid anatomy and terminology — makes it much easier to follow strategy guides and improve.

If you already solve puzzles regularly, you probably don’t need this for yourself. But it makes a great handout for a friend who’s curious, a classroom, or a puzzle club. The terminology section alone saves a lot of explaining.

Why We Made This

At Sudoku a Day, we believe learning Sudoku should feel calm and straightforward. No overwhelming tutorials. No twenty-minute videos for a three-rule game. Just the information you need, presented clearly, ready to print.

We publish free printable Sudoku puzzles every week in five difficulty levels. We have strategy guides that cover everything from basic scanning to expert techniques like X-Wing and Swordfish. And we built an iPhone app that gives you one clean daily puzzle with no ads.

This cheat sheet is part of that same philosophy: useful, minimal, free.

How to Use It

1. Download the PDF using the button below.
2. Print it or save it to your device.
3. Keep it nearby while you solve — especially if you’re just starting out.
4. Graduate from it when the rules feel automatic. Then move on to our strategy cheat sheet for your next level.

When you’re ready, grab a puzzle and start solving. The rules will click faster than you think.

The Three Rules, Briefly

In case you want a refresher right here on the page:

1. Each row must contain the numbers 1–9, each exactly once.
2. Each column must contain the numbers 1–9, each exactly once.
3. Each 3×3 box must contain the numbers 1–9, each exactly once.

No math. No guessing. Just logic.

A properly constructed Sudoku puzzle has exactly one solution, and you can always reach it through deduction alone. That’s what makes it satisfying — every placement is earned.

Print Puzzles to Practice

Once you’ve got the rules down, practice makes everything faster. We publish free printable Sudoku packs every week with puzzles in Easy, Medium, Hard, Expert, and Master difficulty. Each pack includes solutions so you can check your work.

Start with Easy. These puzzles have more givens (pre-filled numbers) and can be solved using just scanning and singles — the simplest techniques. As the rules become second nature, move up to Medium and beyond.

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Keep Learning:

• Sudoku Rules — the full rules explained in detail
• How to Play Sudoku — step-by-step guide for your first puzzle
• Sudoku Strategies — every technique from easy to master
• Free Printable Sudoku Puzzles — weekly puzzle packs in 5 difficulty levels

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