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: Windmill

Author/Opus: This is the 9th puzzle from guest contributor wormsofcan.

Rules: Standard Yajilin 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 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.

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: One Up Two Down

Author/Opus: This is the 9th puzzle from guest contributor Mark Sweep.

Rules: Standard Yajilin rules.

Difficulty: 1.5 stars

Time Standards (highlight to view): Grandmaster = 1:00, Master = 1:45, Expert = 3:30

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.

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: Odd Ones Out

Author/Opus: This is the 15th puzzle from guest contributor Freddie Hand.

Rules: Standard Masyu rules.

Difficulty: 1.5 stars

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

Solution: PDF and solving video.

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

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: Hexed

Author/Opus: This is the 423rd puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Castle Wall rules except on a hexagonal grid.

Difficulty: 5 stars

Time Standards (highlight to view): Grandmaster = 15:30, Master = 21:30, Expert = 43:00

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: Odds

Author/Opus: This is the 378th puzzle from our managing editor Serkan Yürekli.

Rules: Standard Castle Wall 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: 4 stars

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

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: Black Window

Author/Opus: This is the 2nd puzzle from guest contributor Stefan Liew. (This particular puzzle was an early and noteworthy puzzle from @stefpuzzle’s daily Castle Wall series that reached 100 total puzzles.)

Rules: Standard Castle Wall rules.

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 3:30, Master = 4:30, Expert = 9:00

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: 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)

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: 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.