Sudoku Overview

Sudoku is a logic-based number puzzle game played on a 9×9 grid. The goal is to fill each row, column, and 3×3 box with digits 1-9 without repetition.

How to play: Start by identifying cells with only one possible number. Use elimination techniques to narrow down possibilities. Work systematically through rows, columns, and boxes.

Difficulty levels: SudokuPuzzles.net offers 8 difficulty levels from Easy to Insane, with progressive unlocking system for advanced challenges.

Printable & solver: Download free PDF puzzles for offline solving. Use our online solver to check solutions or get hints when stuck.

Sudoku Features

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What Is a Jellyfish in Sudoku? - SudokuPuzzles.net

Jellyfish is a size‑4 fish pattern, generalizing X‑Wing (size 2) and Swordfish (size 3). For a digit d, if four rows restrict d to the same four columns (or vice versa), eliminate d from all other cells in those columns (or rows). When to look for it Hard/Expert-level puzzles where simpler techniques stall. Candidate notes are required—enable notes first.

This article covers Sudoku strategies, techniques, and tips. Learn how to improve your Sudoku solving skills with expert guidance from SudokuPuzzles.net.

Key Topics

  • Sudoku solving techniques and strategies
  • Pattern recognition and elimination methods
  • Advanced Sudoku solving approaches
  • Tips for improving Sudoku skills
  • Common Sudoku mistakes and how to avoid them
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What Is a Jellyfish in Sudoku? - SudokuPuzzles.net

Jellyfish is an advanced fish pattern (like X-Wing, Swordfish). Learn when it appears and how to use it to eliminate candidates.

Jellyfish is a size‑4 fish pattern, generalizing X‑Wing (size 2) and Swordfish (size 3). For a digit d, if four rows restrict d to the same four columns (or vice versa), eliminate d from all other cells in those columns (or rows).

When to look for it

  • Hard/Expert-level puzzles where simpler techniques stall.
  • Candidate notes are required—enable notes first.

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