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Beginner's guide

Sudoku

The 30-second version: fill a 9×9 grid so every row, column and 3×3 box contains the numbers 1–9 exactly once. That's the whole game. There is no math — it's pure pattern logic, and an easy puzzle takes about ten minutes.

Numbers, no math Solo & quiet ~10 min a day Free to start
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How to start (today, in 15 minutes)

Don't read theory for an hour — sudoku is learned by doing. Here are the first three things to actually do.

1

Grab an easy puzzle

Download any free sudoku app and set it to Easy. Yes, easy. Easy puzzles are where techniques make sense; hard puzzles are where beginners quit.

2

Hunt one number

Pick the digit that appears most often — say there are six 5s — and ask: "which rows and boxes still need a 5?" This is scanning, and it alone solves most easy puzzles.

3

Never guess

If you're stuck, you've missed something findable — not something guessable. Walk the rows again. The "aha" when you spot it is the entire reason this hobby is addictive.

Rules & basic techniques

One rule, honestly. Then a handful of named tricks that sound fancier than they are.

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a row — needs 1–9 once a 3×3 box — same deal
1

Every row gets 1–9, no repeats

Nine cells, nine digits. If a row already has a 7, no other cell in that row can be a 7.

2

Every column gets 1–9, no repeats

Same rule, vertical. Rows and columns crossing each other is where all the deductions come from.

3

Every 3×3 box gets 1–9, no repeats

The grid is split into nine chunky boxes. This third constraint is what makes the puzzle sing.

Your first four techniques

Day one

Scanning

Pick a digit, find every copy of it, and see which rows, columns and boxes it locks out. Where's the only place left?

Day one

Crosshatching

Scanning, but aimed at one box: cross out its cells using the rows and columns around it until one cell remains.

Week one

Pencil marks

Write tiny candidate numbers in empty cells. Not cheating — it's literally how champions play. Apps have a button for it.

Week two

Naked singles

A cell whose pencil marks have shrunk to one number. It was hiding in plain sight — fill it in and enjoy the cascade.

Ready for naked pairs, X-wings and other delightfully-named tricks? They're all in the glossary — but honestly, not yet.

Common beginner mistakes

Everyone makes these. Make them less.

Guessing when stuck

A lucky guess teaches you nothing and an unlucky one quietly poisons the whole grid. Stuck = missed deduction. Re-scan.

Starting on "Hard"

Hard puzzles need techniques you haven't met yet. Easy puzzles aren't training wheels — they're where the techniques live.

Keeping it all in your head

Use pencil marks. Mental juggling feels noble and produces errors. Paper exists; so does the notes button.

Thinking it's about math

You never add, subtract or multiply anything. The digits could be fruit. It's pattern logic wearing a number costume.

Recommended apps, books & gear

You need almost nothing — that's part of the charm. These three things cover your whole first year.

[ app screenshot ]
App

A beginner-friendly app

Look for one with hint explanations, a pencil-mark button and a real "easy" mode. Avoid anything that shows ads mid-puzzle.

See our pick →
[ book cover ]
Book

A big book of easy puzzles

Paper forces you to slow down, and crossing off a fat book of 200 easy grids is absurdly satisfying.

See our pick →
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Gear

A pencil you actually like

If you go the paper route: a clicky mechanical pencil and a clean eraser. Pen confidence comes later. Much later.

See our pick →

Heads up: links in this section may be affiliate links. They cost you nothing and keep the guides free.

Your first month, week by week

A gentle ladder. If a week feels too fast, repeat it — there is no falling behind in sudoku.

Week 1

Easy & often

  • One easy puzzle a day
  • Scanning + crosshatching only
  • Finish even when it's slow
Week 2

Add pencil marks

  • Keep the easy difficulty
  • Mark candidates in every empty cell
  • Notice the naked singles appear
Week 3

Step up to medium

  • Two or three medium puzzles
  • Stuck ≠ guess — walk the digits 1–9
  • Learn one new technique: naked pairs
Week 4

Your first hard puzzle

  • Block out a quiet hour
  • No timer, no pressure
  • Finish it and you're not a beginner

Liked the logic? Meet nonograms.

Same "pure deduction" feeling, but you end up with a tiny picture. Most sudoku folks fall hard for them.

Nonograms for beginners →

One easy puzzle habit, weekly

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