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 thirteenth Sunday Stumper of 2022 is an unusual Castle Wall puzzle by Stefan Liew where all the clues are on the “Outside”.

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: Outside

Author/Opus: This is the 3rd puzzle from guest contributor Stefan Liew.

Rules: Standard Castle Wall rules.

Difficulty: 5 stars

Time Standards (highlight to view): Grandmaster = 11:00, Master = 22:30, Expert = 45:00

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 twelfth Sunday Stumper of 2022 is a Yajilin puzzle by Sam Cappleman-Lynes with a tricky path into and out from the “Open Middle”.

(view directly for a larger image)

PDF

or solve online (using our beta test of Penpa-Edit tools using a composite mode where left click inside cell shades square, left click + drag draws line segment, right click inside cell adds dot, and right click on cell edge adds an x.)

Theme: Open Middle

Author/Opus: This is the 13th puzzle from guest contributor Sam Cappleman-Lynes.

Rules: Standard Yajilin rules.

Difficulty: 4.5 stars

Time Standards (highlight to view): Grandmaster = 8:30, Master = 12:30, Expert = 25:00

Solution: PDF and solving video.

Note: Follow this link for classic Yajilin and this link for Yajilin variations. If you are new to this puzzle type, here are our easiest Yajilin to get started on. More Yajilin puzzles can be found in The Art of Puzzles 2, in Yajilin by Murat Can Tonta and Prasanna Seshadri, and in our beginner-friendly book Logic Puzzles 101.

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 eleventh Sunday Stumper of 2022 is a Parking Lot (Hex) puzzle by Murat Can Tonta. Can you pack in all the automobiles (using the empty center and other open space wherever necessary)? Note that we’ve referred to this style before as “Tren”; while not a common puzzle style, we are updating to the nomenclature “Parking Lot” for this stumper.

(view directly for a larger image)

PDF

or solve online (using our beta test of Penpa-Edit tools in Yajilin mode allowing line drawing and cell shading/unmarking; hitting tab can alternate to separate shading and edge drawing modes).

Theme: Empty Center

Author/Opus: This is the 234th puzzle from contributing puzzlemaster Murat Can Tonta.

Rules: Locate some automobiles in the grid having size 1×2 or 1×3. Each number in the grid should be part of an automobile, indicating the number of unoccupied cells the automobile can move to by traveling along its longest axis, stopped only by an edge of the grid or another automobile. (Unlike other variations of this puzzle, there are no extra automobiles without numbers here.)

Also, see this example:

Difficulty: 5 stars

Time Standards (highlight to view): Grandmaster = 21:00, Master = 30:00, Expert = 60:00

Solution: PDF and solving video.

Note: Follow this link for more Parking Lot puzzles.

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?

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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.

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)

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 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.

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 eighth Sunday Stumper of 2022 is a Shape Sudoku by Salih Alan with a “Multiplication” theme in each of the shapes; while it might be a touch easier at 4.5 stars than some of our other stumpers, we expect you’ll still enjoy figuring out the intended solving path.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between Sudoku number entry mode and a shading mode to manage the shape inventory.)

Theme: Multiplication

Author/Opus: This is the 16th puzzle from guest contributor Salih Alan.

Rules: Standard Shape Sudoku rules.

Difficulty: 4.5 stars

Time Standards (highlight to view): Grandmaster = 9:00, Master = 15:00, Expert = 30:00

Solution: PDF and solving video.

Note: Follow this link for other Shape Sudoku. More Shape Sudoku are in Masterpiece Sudoku Mix 8.

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 seventh Sunday Stumper of 2022 is a variation of Japanese Sums by John Bulten.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between number entry and shading modes.)

Theme: Yamato

Author/Opus: This is the 88th puzzle from our contributing puzzlemaster John Bulten.

Rules: Standard Japanese Sums rules: Place the numbers in the indicated range (1-9) in some of the cells so that no number is repeated in any row or column. Numbers on the outside of the grid indicate the sums of adjacent number groups in that row or column, in order. Each sum is separated by at least one unused cell. A ? can represent any sum of 1 or larger.

Also, all unused cells must form an unknown fleet of 1-cell wide ships in the grid. Each segment of a ship occupies a single cell, and ships do not touch each other, even diagonally.

Difficulty: 5 stars

Time Standards (highlight to view): Grandmaster = 18:30, Master = 30:00, Expert = 1:00:00

Solution: PDF and solving video.

Note: Follow this link for other Japanese Sums puzzles.