Printable puzzle book
Slitherlink puzzle book, one hundred loops on paper.
One hundred Slitherlink puzzles in one book, generated and checked by program, laid out to be printed and solved with a pencil. The book is called Otters, it runs to 78 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
- 78 pages, A4 and US Letter both included, solutions at the back
- every loop is unique, and reachable without a single guess
A real page out of the book, exactly as it prints. Tap it for the free five puzzle sample.
for the Otters book, both page sizes, VAT included. All ten books together are 19.90 €, which saves 29.10 € against buying them one by one.
Buy Otters 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 loops, in order of difficulty.
The book holds one hundred Slitherlink 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 small ones at the front to the full sized challenge ones at the end.
In front of the puzzles are the rules with one worked example, so the book stands on its own without this page. At the back are the solutions to all one hundred, numbered to match.
You get two PDF files: one laid out for A4 and one for US Letter, 78 pages each, the same puzzles in both. Black and white, fonts embedded, vector line work, so the dots and clue numbers stay crisp and there is plenty of room to draw the loop by hand.
The rules
Three rules, printed in the front of the book.
- Draw one closed loop along the grid lines. The otters need a single river: no branches, no crossings, no second loop.
- A number in a patch counts its sides. It says how many of that patch's four sides the loop runs along, from 0 to 3. A patch with no number says nothing at all.
- Exactly one loop fits every number. A cross on a side is your own note that the side stays dry.
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 drawing a segment to see whether the loop closes later.
In a loop puzzle that guarantee is worth a lot, because a wrong segment can look right for a long time and only fail at the far corner. Here the deduction is always available somewhere on the page.
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 clue 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 a Slitherlink 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, 78 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.
Is Slitherlink the same as Fences or Loop the Loop?
Yes, those are other names for the same puzzle, along with Takegaki. You draw one closed loop on the grid lines and each number says how many of its cell's four sides the loop uses. Nothing in this book depends on which name you learned it under.
How do I print it?
On any home or office printer, in black and white. Choose the file that matches your paper and print at 100 percent or actual size rather than fit to page, and the grids come out at the size they were drawn, with enough space between the dots to draw a loop in pen.
How do you know every puzzle has one solution?
Because a program checked all one hundred. 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. On top of that the program re-derives every clue from the printed answer and compares it with the printed puzzle.
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 Slitherlink is at <a href="/games/otters/">arling.sk/games/otters</a> and the rules are identical.
Related
More to try.
Play Slitherlink free once a day in the browser: Slitherlink online.
All ten books, 1000 puzzles, 19.90 € together: ten puzzle books.