Hard Sudoku puzzle 20 is a tough daily challenge designed for expert players. Use advanced techniques like hidden triples, quads and X-wing to complete this 9×9 grid without guessing. Stetch your mind with this puzzle selected from the HeadScratcher Sudoku collection.
Hard Sudoku Puzzles Volume 2
250 Large-Format Brain Teasers with Playing Tips and Solutions
250 new hard puzzles, with the same clean two-per-page layout, starter notes, QR codes, and full solutions. If you enjoyed Volume 1, this is the perfect next step.
- Expert-level: Designed for experienced solvers.
- Learn by doing: Includes Triples, Quads, and X-Wing alongside Pairs, Pointing, and Claiming.
- Get started fast: 50 puzzles include pre-filled candidate notes to show how pros set up a grid.
- Two puzzles per page: Spacious A4 pages leave plenty of room for neat pencil marks.
- Paper + online: Scan a QR code for every puzzle to play digitally at headscratcher.world.
- Solutions included: Complete solution grids for every puzzle.
Frequently Asked Questions
What makes this Sudoku puzzle hard?
Hard puzzles offer fewer obvious entries and require deeper planning. You’ll need strong candidate notes and multi-step reasoning to unlock the grid.
What techniques help with hard Sudoku puzzles?
In addition to the basics (full house and singles), hard puzzles reward careful use of triples, quads, X-wing and more advanced candidate-based logic.
How long does a hard Sudoku usually take?
Hard puzzles often take 20–45 minutes or more, even for confident solvers. They’re designed to be thoughtful challenges rather than quick warm-ups.
Will I ever need to guess on a hard puzzle?
No. All HeadScratcher puzzles, including the hardest grids, are constructed to be logically solvable without guessing and to have a single unique solution.
Can I still use hints on hard Sudoku puzzles?
Yes. Hints are available if you get stuck and are written to teach the reasoning, not just give away the answer, so you can improve for next time.