This year, we have started to have some extra difficult Sunday Stumpers, about once a month. These will be quite tough puzzles, but with a logical path to be found (and solution videos to help). This fourth Sunday Stumper is a Slitherlink puzzle with two variant rules added to it.

PDF

or solve online (using our beta test of Penpa-Edit tools; in default edgexoi mode: left-click+drag draws line, right click marks X on edge, clicking inside a cell alternates color to yellow then green then white; hitting tab will alternate to a number entry mode that can be used to write over the letter clues and hitting tab again will go back to edgexoi.)

Theme: From Here to Maternity

Author/Opus: This is the 78th puzzle from our contributing puzzlemaster John Bulten.

Rules: Standard Slitherlink rules. The letters A, M, O, and Y stand for different digits from 0 – 3. Also, an even number of cells in each row and in each column must be inside the loop.

Difficulty: 4.5 stars

Time Standards (highlight to view): Grandmaster = 17:30, Master = 25:00, Expert = 50:00

Solution: PDF; a solution video is also available here.

Note: Follow this link for classic Slitherlink and this link for Slitherlink variations. If you are new to this puzzle type, here are our easiest Slitherlink puzzles to get started on. More Slitherlink puzzles can be found in The Art of Puzzles, Slitherlink and Variations, and our beginner-friendly book Logic Puzzles 101.

PDF

or solve online (using our beta test of Penpa-Edit tools)

Theme: Pentominoes

Author/Opus: This is the 12th puzzle from guest contributor Zoltán Horváth.

Rules: Standard Thermo-Sudoku rules.

Difficulty: 4 stars

Time Standards (highlight to view): Grandmaster = 6:45, Master = 9:30, Expert = 19:00

Solution: PDF; a solution video is also available here.

Note: Follow this link for more Thermo-Sudoku puzzles. If you are new to this puzzle type, here are our easiest Thermo-Sudoku to get started on. More Thermo-Sudoku puzzles can be found in The Art of Sudoku 2 and Masterpiece Sudoku Mix 2.

PDF

or solve online (using our beta test of Penpa-Edit tools)

Theme: Diagonals

Author/Opus: This is the 69th puzzle from our contributing puzzlemaster Ashish Kumar.

Rules: Standard Sudoku rules.

Difficulty: 3.5 stars

Time Standards (highlight to view): Grandmaster = 3:45, Master = 8:45, Expert = 17:30

Solution: PDF; a solution video is also available here.

Note: Follow this link for other classic Sudoku. If you are new to this puzzle type, here are our easiest Sudoku to get started on. More classic Sudoku puzzles can be found in The Art of Sudoku, The Art of Sudoku 2 and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

PDF

or solve online (using our beta test of Penpa-Edit tools)

Theme: Pamukkale Travertines

Author/Opus: This is the 325th puzzle from our managing editor Serkan Yürekli.

Rules: Standard Isodoku rules, using numbers 1-8.

Difficulty: 3.5 stars

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

Solution: PDF; a solution video is also available here.

Note: Follow this link for other Isodoku. If you are new to this puzzle type, here are our easiest Isodoku to get started on.

PDF

or solve online (using our beta test of Penpa-Edit tools)

Theme: Diamond

Author/Opus: This is the 2nd puzzle from guest contributor R. Kumaresan.

Rules: Standard Sudoku rules.

Difficulty: 3 stars

Time Standards (highlight to view): Grandmaster = 3:45, Master = 5:45, Expert = 11:30

Solution: PDF; a solution video is also available here.

Note: Follow this link for other classic Sudoku. If you are new to this puzzle type, here are our easiest Sudoku to get started on. More classic Sudoku puzzles can be found in The Art of Sudoku, The Art of Sudoku 2 and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

PDF

or solve online (using our beta test of Penpa-Edit tools)

Theme: Even Odd Squares

Author/Opus: This is the 381st puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Sudoku rules.

Difficulty: 2 stars

Time Standards (highlight to view): Grandmaster = 1:40, Master = 2:45, Expert = 5:30

Solution: PDF; a solution video is also available here.

Note: Follow this link for other classic Sudoku. If you are new to this puzzle type, here are our easiest Sudoku to get started on. More classic Sudoku puzzles can be found in The Art of Sudoku, The Art of Sudoku 2 and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between Sudoku = big entries and Number candidate = small entries in the corners of cells.)

Theme: Singles

Author/Opus: This is the 343rd puzzle from our contributing puzzlemaster Grant Fikes.

Rules: Standard Tight Fit Sudoku rules. Remember, the smaller number goes above the larger number in all slashed cells. The range of this puzzle is 1-9.

Difficulty: 1 star

Time Standards (highlight to view): Grandmaster = 0:50, Master = 1:30, Expert = 3:00

Solution: PDF; a solution video is also available here.

Note: Follow this link for other Tight Fit Sudoku puzzles on this website. If you are new to this puzzle type, here are our easiest Tight Fit Sudoku to get started on. More Tight Fit Sudoku can be found in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli, in The Art of Sudoku 2, and in Masterpiece Sudoku Mix 5: Tight Fit Sudoku.

PDF

or solve online (using our beta test of Penpa-Edit tools)

Theme: 0123

Author/Opus: This is the 198th puzzle from our contributing puzzlemaster Murat Can Tonta.

Rules: Standard Nurikabe rules.

Difficulty: 3.5 stars

Time Standards (highlight to view): Grandmaster = 3:30, Master = 9:00, Expert = 18:00

Solution: PDF; a solution video is also available here.

Note: Follow this link for classic Nurikabe and this link for Nurikabe variations. If you are new to this puzzle type, here are our easiest Nurikabe puzzles to get started on. More Nurikabe puzzles can be in The Art of Puzzles, in our beginner-friendly book Logic Puzzles 101, and in the e-book Nurikabe by Ashish Kumar.

PDF

or solve online (using our beta test of Penpa-Edit tools)

Theme: Diamond Archipelago

Author/Opus: This is the 380th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Variation of Nurikabe rules. Every region of white cells must contain exactly two numbers (instead of one) and have total size equal to the sum of the two numbers.

Also, see this example:

Difficulty: 3.5 stars

Time Standards (highlight to view): Grandmaster = 4:00, Master = 6:15, Expert = 12:30

Solution: PDF; a solution video is also available here.

Note: Follow this link for classic Nurikabe and this link for Nurikabe variations. If you are new to this puzzle type, here are our easiest Nurikabe puzzles to get started on. More Nurikabe puzzles can be in The Art of Puzzles, in our beginner-friendly book Logic Puzzles 101, and in the e-book Nurikabe by Ashish Kumar.

PDF

or solve online (using our beta test of Penpa-Edit tools)

Theme: Windmill

Author/Opus: This is the 68th puzzle from our contributing puzzlemaster Ashish Kumar.

Rules: Standard Nurikabe rules. Also, the numbers outside the grid show the number of shaded segments visible in that direction (as in Skyscrapers). A shaded segment of length N in a given direction is taken as a building of height N. A building blocks the view of any building behind it of equal or lesser height.

Also, see this example:

Difficulty: 3 stars

Time Standards (highlight to view): Grandmaster = 2:30, Master = 4:30, Expert = 9:00

Solution: PDF; a solution video is also available here.

Note: Follow this link for classic Nurikabe and this link for Nurikabe variations. If you are new to this puzzle type, here are our easiest Nurikabe puzzles to get started on. More Nurikabe puzzles can be in The Art of Puzzles, in our beginner-friendly book Logic Puzzles 101, and in the e-book Nurikabe by Ashish Kumar.