Printable puzzle book
Anti-knight Sudoku puzzle book, one hundred grids on paper.
One hundred anti-knight Sudoku puzzles in one book, generated and checked by program, laid out to be printed and solved with a pencil. The book is called Hares, it runs to 108 pages, and it comes as two PDFs, one sized for A4 and one for US Letter.
- 100 puzzles: 25 easy, 30 medium, 30 hard, 15 challenge, in that order
- 108 pages, A4 and US Letter both included, solutions at the back
- every puzzle has exactly one solution, and a program proves it
A real page out of the book, exactly as it prints. Tap it for the free five puzzle sample.
for the Hares book, both page sizes, VAT included. All ten books together are 19.90 €, which saves 29.10 € against buying them one by one.
Buy Hares for 4.90 € All ten for 19.90 €The buy button takes you to the shelf page, where the payment and the download live. Seller: ARLing s. r. o., Company ID 56583486, Bratislava. Stripe is merchant of record and issues the receipt. Terms and Withdrawal.
What is inside
One hundred grids, in order of difficulty.
The book holds one hundred anti-knight Sudoku puzzles and nothing else: 25 easy, 30 medium, 30 hard and 15 challenge, arranged so that difficulty rises through the book without a jump in the middle. The grids grow with it, from smaller ones at the front to the full sized challenge ones at the end.
Each puzzle states above the grid which rules are in force, because the harder ones add the non consecutive rule on top of the knight rule. In front of the puzzles are the rules with one worked example, so the book stands on its own without this page, and at the back are the solutions to all one hundred.
You get two PDF files: one laid out for A4 and one for US Letter, 108 pages each, the same puzzles in both. Black and white, fonts embedded, vector line work, with cells left clear for corner and centre pencil marks.
The rules
Three rules, printed in the front of the book.
- Every row, every column and every block holds each number once, exactly as in ordinary Sudoku.
- Hares leap like a knight. Two cells a knight's leap apart, two one way and one across, never hold the same number. The leap reaches over rows, columns and blocks alike.
- In the harder grids the same number may not sit next to itself in any direction, corners included. Each puzzle says above it which rules are in force.
One solution
Hard to see, not hard to guess.
A puzzle book can say unique solution and mean that somebody checked the answer once. We mean something narrower. Each puzzle is built by a program that also solves it, and the solver is asked to find two solutions; the puzzle is kept only if it finds exactly one, and only if it reached that one by applying rules rather than by writing a digit to see what happens.
The extra rules are applied by that same solver, with the exact set each puzzle declares, so a grid is never harder or easier than the line above it says.
Two more things the program checks before the book is printed: no two puzzles are the same, and no two have the same answer. The program also re-derives every given from the printed answer and compares it with the printed puzzle.
Before you pay
Look at it first.
- Free sample, five puzzles (PDF)
Taken from all four difficulty levels, so you can see the hard end before you decide. No account, no e-mail.
- Play an anti-knight Sudoku free today
A new one every midnight in the browser, with hints that explain themselves. The book holds different puzzles from the daily ones.
- All ten books on one page
Ten kinds of logic puzzle, 1000 puzzles in all, 19.90 € for the lot.
Questions
Before you pay.
What exactly do I get?
Two PDF files: one laid out for A4 and one for US Letter, 108 pages each. The puzzles are the same in both, only the page size differs. Both are black and white with the fonts embedded, there is no DRM and no account, and the files are yours to keep and print as often as you like.
What does anti-knight mean?
That two cells a chess knight's move apart, two squares one way and one across, may not hold the same number. It applies across block boundaries, so one placed digit can rule out up to eight further cells scattered around the grid. The ordinary Sudoku rules still hold on top of it.
Do all one hundred puzzles use the same rules?
No, and each one says so above the grid. The harder puzzles add the non consecutive rule, meaning the same number may not sit next to itself in any direction including diagonally. You are never left guessing which variant you are solving.
How do you know every puzzle has one solution?
Because a program checked all one hundred, with exactly the rule set each puzzle declares. The solver is run with a limit of two solutions; if it finds a second one the puzzle is thrown away. It also has to reach the solution by rules alone, without trial and error.
Can I get my money back?
By law, no, and we would rather say so before you pay. Digital content delivered immediately with your consent carries no right of withdrawal: in Slovakia that is section 19 paragraph 1 letter m) of Act No. 108/2024 Coll., across the EU Article 16 letter m) of Directive 2011/83/EU. The free sample exists precisely so you can decide first. If a file is broken or a puzzle is wrong, write to andrej@arling.sk.
Are these the same puzzles as the free daily game?
No. The book holds different puzzles from the daily ones, so nothing in it is a repeat. The free daily anti-knight Sudoku is at <a href="/games/hares/">arling.sk/games/hares</a> and the rules are identical.
Related
More to try.
Play anti-knight Sudoku free once a day in the browser: anti-knight Sudoku online.
All ten books, 1000 puzzles, 19.90 € together: ten puzzle books.