PDF

or solve online (using our beta test of Penpa-Edit tools in edgex mode where left click+drag draws lines and right click marks X’s)

Theme: Symmetry and Logic

Author/Opus: This is the 4th puzzle from guest contributor Hans van Stippent (who has also contributed these three Sunday Surprises).

Rules: Standard Slitherlink rules. Also, there are some sheep (marked S) that must be inside the loop and some wolves (marked W) that must be outside the loop.

Answer String: Enter the length in cells of each of the internal loop segments following the arrows for the marked rows, starting at the top. Separate each row’s entry with a comma.

Time Standards (highlight to view): Grandmaster = 2:45, Master = 5:00, Expert = 10:00

Solution: PDF; a solution video is available here.

Note: Follow this link for other Slitherlink variations and this link for classic Slitherlink. If you are new to this puzzle type, here are our easiest Slitherlink puzzles to get started on.

PDF

or solve online (using our beta test of Penpa-Edit tools in edgex mode where left click+drag draws lines and right click marks X’s)

Theme: Quadrants

Author/Opus: This is the 14th puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: Combination of Slitherlink and Masyu rules.

Specifically, draw a single closed loop by connecting neighboring dots horizontally or vertically so that each number represents the number of adjacent edges used by the loop. The loop passes through all large circles. It must go straight through the white circles with at least one side turning at the next dot; it must turn at the black circles and then go straight through the next dot in both directions.

Answer String: Enter the length in cells of each of the internal loop segments from left to right for the marked rows, starting at the top. Separate each row’s entry with a comma.

Time Standards (highlight to view): Grandmaster = 1:40, Master = 2:30, Expert = 5:00

Solution: PDF

Note: Follow these links for other Slitherlink variations and Masyu variations. Or follow these links for classic Slitherlink and classic Masyu puzzles.

PDF

or solve online (using our beta test of Penpa-Edit tools in edgex mode where left click+drag draws lines and right click marks X’s)

Theme: Logical Variation

Author/Opus: This is the 87th puzzle from our contributing puzzlemaster Grant Fikes.

Rules: Variation of Slitherlink rules. The loop may now intersect itself at a point (it still may not coincide anywhere). At any dot at which more than 2 segments meet, the segments must all travel straight through the dot. This example may help:

Answer String: For each marked row, enter the length in cells of each connected group inside the loop from left to right. Separate each row’s entry with a comma. Shading the loop so that each fence separates a shaded/unshaded cell can help identify what is inside. For the example, the answer would be “11,12”.

Time Standards (highlight to view): Grandmaster = 4:00, Master = 6:30, Expert = 13:00

Solution: PDF

Note: Follow this link for other Slitherlink variations and this link for classic Slitherlink. If you are new to this puzzle type, here are our easiest Slitherlink puzzles to get started on.

PDF

or solve online (using our beta test of Penpa-Edit tools in edgex mode where left click+drag draws lines and right click marks X’s)

Theme: Surrounded!

Author/Opus: This is the 154th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Slitherlink rules. Also, there are some sheep (marked S) that must be inside the loop and some wolves (marked W) that must be outside the loop.

Answer String: Enter the length in cells of each of the internal loop segments following the arrows for the marked rows, starting at the top. Separate each row’s entry with a comma.

Time Standards (highlight to view): Grandmaster = 2:30, Master = 3:30, Expert = 7:00

Solution: PDF

Note: Follow this link for other Slitherlink variations and this link for classic Slitherlink. If you are new to this puzzle type, here are our easiest Slitherlink puzzles to get started on.

PDF

or solve online (using our beta test of Penpa-Edit tools; ue tab to alternate between edgex mode where left click+drag draws lines and right click marks X’s and shading and number entry modes.)

Theme: Symmetry and Logic

Rules: Variation of standard Slitherlink rules. First, place the ten dominoes given below the grid into the gray areas, without overlapping, to form a valid Slitherlink puzzle; dominoes can be rotated. Solve the resulting Slitherlink following normal rules. (Note: The set of digits placed into the grid from the dominoes is unique, but the assignment of dominoes need not be unique.)

Answer String: Enter the length in cells of each of the internal loop segments from left to right for the marked rows, starting at the top. Separate each row’s entry with a comma.

Time Standards (highlight to view): Grandmaster = 7:30, Master = 17:30, Expert = 35:00

Solution: PDF

PDF

or solve online (using our beta test of Penpa-Edit tools in edgex mode where left click+drag draws lines and right click marks X’s)

Theme: Unfriendly Neighbors

Rules: Standard Slitherlink rules. Also, there are some sheep (marked S) that must be inside the loop and some wolves (marked W) that must be outside the loop.

Answer String: Enter the length in cells of each of the internal loop segments following the arrows for the marked rows, starting at the top. Separate each row’s entry with a comma.

Time Standards (highlight to view): Grandmaster = 2:15, Master = 3:00, Expert = 6:00

Solution: PDF

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between edgex mode where left click+drag draws lines and right click marks X’s and a shading mode to mark true/false clues.)

This is a “Franken-Friday” puzzle variation.

Theme: Logical

Rules: Variation of standard Slitherlink rules. Exactly one clue in each row and column is lying and must represent a different number.

Answer String: Enter the length in cells of each of the internal loop segments from left to right for the marked rows, starting at the top. Separate each row’s entry with a comma.

Time Standards (highlight to view): Grandmaster = 6:45, Master = 12:00, Expert = 24:00

Solution: PDF

PDF

or solve online (using our beta test of Penpa-Edit tools in edgex mode where left click+drag draws lines and right click marks X’s)

This is a “Franken-Friday” puzzle variation.

Theme: Hex Pill

Rules: Standard Slitherlink rules.

Answer String: Enter the length in cells of each of the internal loop segments following the arrows for the marked rows, starting at the top. Separate each row’s entry with a comma.

Time Standards (highlight to view): Grandmaster = 4:45, Master = 7:30, Expert = 15:00

Solution: PDF

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between edgex mode where left click+drag draws lines and right click marks X’s and a line drawing mode to mark the dominoes.)

This is a “Twisted Tuesday” puzzle variation.

Theme: Double Domino – both domino-based clue groupings, and a domino-based loop.

Rules: Standard Slitherlink rules; also, the interior of the loop must be divisible into dominoes (1×2 rectangles) in at least one way without any overlaps.

Answer String: Enter the length in cells of each of the internal loop segments from left to right for the marked rows, starting at the top. Separate each row’s entry with a comma.

Time Standards (highlight to view): Grandmaster = 4:30, Master = 7:00, Expert = 14:00

Editorial Note: This puzzle is a fair bit more difficult than our usual Tuesday puzzles, but this may be a side effect of the new Twisted Tuesday format.

Solution: PDF

In addition to FoxFireX’s incredible sudoku gift that he made for someone’s birthday (some puzzles are meant to keep more private), we got three other submissions for our first Hidden Contest. We’re posting them here in increasing order of difficulty.

First up is an “Anti-Symmetry” Nurikabe from Giovanni P. where every clue that is odd/even has an even/odd clue in the corresponding symmetric place. Standard Nurikabe rules are all you need for this challenge.

Solution image

Next up is a real RARITY for this website, a Shakashaka. For the general rules, we’ll direct you to Nikoli.com where the puzzle originated. Here, Bryce Herdt has made a cipher version of the puzzle. The letters AIRTY each stand for a different number from 0 – 4 which the solver must determine.

Solution image

Finally, the hardest of the bunch, is an intriguing variation called “Sudoku Slitherlink” by its designer Scott Handelman. In addition to standard Slitherlink rules, a different number from 0-3 must go into each green cell. No number in a green cell can repeat in that row or column. As Scott warns, this is one of the hardest puzzles he’s constructed and, from his original post, he’s “still kinda shocked that the middle just kinda ‘works'”.

Solution image

All of these puzzles are grouped in this single PDF.

If you enjoy these puzzles, please comment here and say so, thanking each of the authors. As contest entries, these didn’t go through editorial review (except making sure there was a single answer), but we found them all quite interesting and worthy of being some of the first puzzles from other authors to appear on this web-site. We’re considering keeping Sunday open for “guest” submissions each week from new puzzle authors. And once we get through a stack of puzzle submissions for The Art of Puzzles, more authors will be appearing throughout the week too.