PDF

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

Theme: Black Box

Author/Opus: This is the 57th puzzle from our contributing puzzlemaster JinHoo Ahn.

Rules: Standard Castle Wall rules.

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 2:00, Master = 3:45, Expert = 7:30

Solution: PDF and solving video.

Note: Follow this link for more Castle Wall puzzles. If you are new to this puzzle type, here are our easiest Castle Wall puzzles to get started on. More Castle Wall puzzles can be found in our beginner-friendly collection Intro to GMPuzzles as well as the larger collection Castle Wall, both by Serkan Yürekli.

PDF

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

Theme: Windmill

Author/Opus: This is the 17th puzzle from guest contributor Jonas Gleim.

Rules: Standard Castle Wall rules.

Difficulty: 2 stars

Time Standards (highlight to view): Grandmaster = 1:15, Master = 2:30, Expert = 5:00

Solution: PDF and solving video.

Note: Follow this link for more Castle Wall puzzles. If you are new to this puzzle type, here are our easiest Castle Wall puzzles to get started on. More Castle Wall puzzles can be found in our beginner-friendly collection Intro to GMPuzzles as well as the larger collection Castle Wall, both by Serkan Yürekli.

PDF

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

Theme: 4×4

Author/Opus: This is the 244th puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: Standard Castle Wall rules.

Difficulty: 2 stars

Time Standards (highlight to view): Grandmaster = 1:20, Master = 2:00, Expert = 4:00

Solution: PDF and solving video.

Note: Follow this link for more Castle Wall puzzles. If you are new to this puzzle type, here are our easiest Castle Wall puzzles to get started on. More Castle Wall puzzles can be found in our beginner-friendly collection Intro to GMPuzzles as well as the larger collection Castle Wall, both by Serkan Yürekli.

Since 2021, we have posted 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 tenth Sunday Stumper of 2022 is a Tapa-Like Loop (Transparent) puzzle by Prasanna Seshadri. Will all the cells be used in this puzzle like the title and the clues suggest?

(view directly for a larger image)

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

Theme: All Cells?

Author/Opus: This is the 243rd puzzle from contributing puzzlemaster Prasanna Seshadri.

Rules: Variation of Tapa-Like Loop rules. (Form a single non-intersecting loop. Clues inside the grid represent the number of neighboring cells visited by the loop; if there is more than one number in a cell, each number should be represented with a separate loop segment. There is no 2×2 rule of Tapa in this puzzle.)

The loop can travel through clue cells. Each clue now describes the entire 3×3 area the clue cell is in the middle of.

See also this example:

Difficulty: 5 stars

Time Standards (highlight to view): Grandmaster = 32:00, Master = 45:00, Expert = 1:30:00

Solution: PDF and solving video.

Note: Follow this link for other Tapa-Like Loop puzzles. More Tapa-Like Loop puzzles can be found in the Tapa-Like Loop Collection by Prasanna Seshadri.

PDF

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

Theme: Groups of Three

Author/Opus: This is the 25th puzzle from our contributing puzzlemaster Takeya Saikachi.

Rules: Variation of Tapa: Form a single non-intersecting loop. Clues inside the grid represent the number of neighboring cells visited by the loop; if there is more than one number in a cell, each number should be represented with a separate loop segment. There is no 2×2 rule of Tapa in this puzzle.

See also this example:

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 2:00, Master = 3:45, Expert = 7:30

Solution: PDF and solving video.

Note: Follow this link for other Tapa-Like Loop puzzles. More Tapa-Like Loop puzzles can be found in the Tapa-Like Loop Collection by Prasanna Seshadri.

Since 2021, we have posted 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 ninth Sunday Stumper of 2022 is a Slitherlink (Switch) puzzle by Matej Uher, author of our new Slitherlink and Variations 2 book. Each clue here has to switch with one of its orthogonal neighbors, so it will be quite a challenge to find the complete loop.

(view directly for a larger image)

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

Theme: Knight’s Moves

Author/Opus: This is the 5th puzzle from guest contributor Matej Uher.

Rules: Standard Slitherlink rules. Also, each given clue has to switch its initial position with one of its adjacent neighbors.

Also, see this example:

Difficulty: 5 stars

Time Standards (highlight to view): Grandmaster = 30:00, Master = 45:00, Expert = 1:30:00

Solution: PDF and solving video.

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; use tab to switch between edgex mode where left click+drag draws lines and right click marks X’s, and a shading and number entry mode to mark/update the liar clues.)

Theme: Bull’s-Eye

Author/Opus: This is the 419th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Variation of Slitherlink rules. Exactly one clue in each row and column is incorrect and must represent another number.

Difficulty: 4.5 stars

Time Standards (highlight to view): Grandmaster = 8:45, Master = 13:30, Expert = 27:00

Solution: PDF and solving video.

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 in edgex mode where left click+drag draws lines and right click marks X’s)

Theme: Columns

Author/Opus: This is the 11th puzzle from guest contributor Michael Tang.

Rules: Standard Slitherlink rules.

Difficulty: 3 stars

Time Standards (highlight to view): Grandmaster = 2:30, Master = 5:15, Expert = 10:30

Solution: PDF and solving video.

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 in edgex mode where left click+drag draws lines and right click marks X’s)

Theme: Empty Middle

Author/Opus: This is the 231st puzzle from our contributing puzzlemaster Murat Can Tonta.

Rules: Standard Slitherlink rules, but any two consecutive line segments cannot have the same length (i.e., on both sides of any turn, the loop must travel different lengths).

Difficulty: 3 stars

Time Standards (highlight to view): Grandmaster = 2:30, Master = 5:00, Expert = 10:00

Solution: PDF and solving video.

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 in edgex mode where left click+drag draws lines and right click marks X’s)

Theme: Pairs

Author/Opus: This is the 11th puzzle from guest contributor Eric Fox.

Rules: Standard Slitherlink rules.

Difficulty: 2 stars

Time Standards (highlight to view): Grandmaster = 1:30, Master = 2:00, Expert = 4:00

Solution: PDF and solving video.

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.