PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between shading mode and the linex mode where left click+drag draws lines and right click marks X’s)

Theme: Twins

Author/Opus: This is the 14th puzzle from guest contributor Sam Cappleman-Lynes.

Rules: Shade some empty cells black so that each number indicates the total count of white cells connected vertically and horizontally to that number including the numbered cell itself. Black cells cannot share an edge, and all white cells must belong to a single connected group.

Also see this example:

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 1:45, Master = 2:30, Expert = 5:00

Solution: PDF and solving video.

Note: Follow this link for more Kuromasu puzzles. More Kuromasu can be found in Grandmaster Puzzles Quarterly Vol. 3.

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.

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: 4×4 Grid

Author/Opus: This is the 11th puzzle from guest contributor David Altizio.

Rules: Standard Yajilin rules.

Difficulty: 4 stars

Time Standards (highlight to view): Grandmaster = 7:00, Master = 9:45, Expert = 19:30

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 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: Divided by 1

Author/Opus: This is the 2nd puzzle from guest contributor Chandrachud Nanduri.

Rules: Standard Yajilin rules. Also, the loop must go straight through the cells with white circles, with a turn in at least one of the cells immediately before/after each white circle. The loop must make a turn in all the black circles, but must go straight in both cells immediately before/after each black circle.

Difficulty: 2.5 stars

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

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: 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)

Theme: Four Slices of Pi

Author/Opus: This is the 8th puzzle from guest contributor Mark Sweep.

Rules: Standard Cross the Streams rules.

Difficulty: 4.5 stars

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

Solution: PDF and solving video.

Note: Follow this link for other Cross the Streams. If you are new to this puzzle type, here are our easiest Cross the Streams to get started on. More Cross the Streams can be found in these e-books in our store.

PDF

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

Theme: Any Questions?

Author/Opus: This is the 10th puzzle from guest contributor David Altizio.

Rules: Standard Cross the Streams rules, except that the puzzle uses an early number system that only has the concepts of “one” and “many”. All number clues greater than 1 are represented by a + symbol.

Difficulty: 4 stars

Time Standards (highlight to view): Grandmaster = 4:30, Master = 10:30, Expert = 21:00

Solution: PDF and solving video.

Note: Follow this link for other Cross the Streams. If you are new to this puzzle type, here are our easiest Cross the Streams to get started on. More Cross the Streams can be found in these e-books in our store.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between shading mode and the linex mode where left click+drag draws lines and right click marks X’s)

Theme: Surrounded by 258

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

Rules: Standard Cave rules.

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 3:45, Master = 4:45, Expert = 9:30

Solution: PDF and solving video.

Note: Follow this link for classic Caves and this link for Cave variations. If you are new to this puzzle type, here are our easiest Cave Puzzles to get started on. More Cave puzzles can be found in Roger Barkan’s Colossal Cave Collection, in The Art of Puzzles, 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: Three Square Meals

Author/Opus: This is the 8th puzzle from guest contributor Jeffrey Bardon.

Rules: Standard TomTom rules, using the integers 1-6.

Difficulty: 2 stars

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

Solution: PDF and solving video.

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