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Super Sudoku
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How to Play

Sudoku in five minutes. No maths needed.

Sudoku uses numbers, but it is a logic puzzle: you never add anything up. Here are the rules, the first techniques and the mistakes to avoid.

The rule

Every row, column and box holds 1 to 9 once

The grid has 81 cells: 9 rows, 9 columns and nine 3×3 boxes (outlined in bold). Some numbers are given at the start.

Fill every empty cell with a number from 1 to 9 so that no number repeats in any row, any column or any box. A correct puzzle has exactly one solution.

Sudoku grid with row 2, column 7 and the bottom-left box shaded547925898568597426853791139215287953587
One row (left to right), one column (top to bottom) and one 3×3 box, each shaded. Each must end up with 1–9 exactly once.
Placing numbers

Three ways to find a number

Top row with one empty cell that must be 853467891225898568597426853791139215287953587
The last gap in a row. The top row has 1–7 and 9; only 8 is missing, so the gold cell is 8.
Centre box with one empty cell that must be 5547925898568597614268537911392415287953587
The last gap in a box. The centre box has every number except 5, so its empty cell is 5.
Scanning example: the only place for 1 in the top-left box11111
Scanning (cross-hatching). Where can 1 go in the top-left box? The 1s in rows 1–2 and columns 2–3 rule out every cell but one.
Beginner tips

Habits that make every puzzle easier

  • 01

    Start where it's crowded

    Rows, columns and boxes with the most numbers have the fewest options left.

  • 02

    Go number by number

    Pick a digit, say 1, and look for every box where it can only go in one cell.

  • 03

    Use notes

    When a cell could hold two or three numbers, write them as notes and cross them out as you go.

  • 04

    Check all three

    Before placing a number, check its row, its column and its 3×3 box.

  • 05

    Don't guess

    Every puzzle can be solved by logic. If you are stuck, scan again or use a hint.

  • 06

    Undo freely

    Undo takes back a move, so trying an idea from your notes costs nothing.

Common mistakes

What trips beginners up

  • Forgetting the box

    A number can be fine in its row and column and still repeat inside its 3×3 box.

  • Stale notes

    After placing a number, remove it from the notes in the same row, column and box.

  • Rushing on Hard and Expert

    In the app the fourth mistake ends the game: slow down when the board gets tight.

Row with the number 7 written twice, marked in red85977
A mistake: 7 appears twice in the same row. In the app a wrong number is marked and counts as one of your three allowed mistakes.
Difficulty

How the levels progress

Harder levels give fewer starting numbers, so the simple techniques above run out sooner and you need notes and longer chains of logic.

  1. Step 1

    Easy

    Perfect for beginners. Plenty of clues to get started.

  2. Step 2

    Medium

    A balanced challenge for casual players.

  3. Step 3

    Hard

    Fewer clues. Requires advanced techniques.

  4. Step 4

    Expert

    Minimal clues. Only for the brave.

Ready to try? Play a puzzle in your browser or read advanced strategies.

Practise every day in the app

Four difficulty levels, notes, hints and a new Daily Challenge every day.

Get it onGoogle Play