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

Theme: Clue Symmetry and Logic

Author/Opus: This is the 28th puzzle from our contributing puzzlemaster Ashish Kumar and 347th from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Yajilin rules, except that instead of blackening single cells, blacken in dominoes (1×2 rectangles). Clues indicate the total number of dominoes (not the total number of cells) that are shaded in the given direction.

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma.

Time Standards (highlight to view): Grandmaster = 3:30, Master = 4:15, Expert = 8:30

Solution: PDF

Note: Follow this link for other variations of Yajilin and this link for classic Yajilin. 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: Big +, Small +

Author/Opus: This is the 176th puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: Variation of Yajilin. Blacken some white cells and then draw a single closed loop (without intersections or crossings) through all remaining white cells. Blackened cells cannot share an edge with each other. A number in a region indicates how many white cells must be blackened. Cells with number clues may be blackened.

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma.

Time Standards (highlight to view): Grandmaster = 3:15, Master = 4:30, Expert = 9:00

Solution: PDF

Note: Follow this link for other variations of Yajilin and this link for classic Yajilin. 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: Every Which Way but Up

Author/Opus: This is the 13th puzzle from guest contributor Joseph Howard.

Rules: Variation of Yajilin rules, including both diagonal arrows and transparent clues that the loop can pass through. Any clue cells that are part of the loop must be true and indicate the number of shaded cells in that direction. Any clue cell that is not part of the loop must be blackened, and the clue value MUST also be false (e.g., if a 2 left clue is blackened, there must be some number of cells other than 2 blackened to the left of the clue).

See also this example:

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma.

Time Standards (highlight to view): Grandmaster = 4:15, Master = 10:30, Expert = 21:00

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

Note: Follow this link for other classic Yajilin. 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: Entrance and Exit

Author/Opus: This is the 242nd puzzle from our contributing puzzlemaster Serkan Yürekli.

Rules: Standard Yajilin rules, except that instead of blackening single cells, blacken in dominoes (1×2 rectangles). Clues indicate the total number of dominoes (not the total number of cells) that are shaded in the given direction.

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma.

Time Standards (highlight to view): Grandmaster = 3:15, Master = 5:30, Expert = 11:00

Solution: PDF

Note: Follow this link for other variations of Yajilin and this link for classic Yajilin. 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: Clue Symmetry and Logic

Author/Opus: This is the 91st puzzle from our contributing puzzlemaster Murat Can Tonta.

Rules: Variation of Yajilin. Blacken some white cells and then draw a single closed loop (without intersections or crossings) through all remaining white cells. Blackened cells cannot share an edge with each other. A number in a region indicates how many white cells must be blackened. Cells with number clues may be blackened.

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma.

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

Solution: PDF

Note: Follow this link for other variations of Yajilin and this link for classic Yajilin. 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.

PDF

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

Theme: A Migratory Bird

Author/Opus: This is the 190th puzzle from our contributing puzzlemaster Serkan Yürekli.

Rules: Standard Yajilin rules. Also, enter a number into each gray cell to represent the total number of blackened cells in the given direction. Numbers cannot repeat in a row or column.

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma.

Time Standards (highlight to view): Grandmaster = 1:45, Master = 3:00, Expert = 6:00

Solution: PDF

Note: Follow this link for other variations of Yajilin and this link for classic Yajilin. 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.

While not a Pentominous puzzle, we wanted to share a cool Pentominoes loop puzzle variant from Murat this week, who is a co-author with Grant Fikes of Plenty o’ Pentominous, released this week.

(view directly for a larger image)

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Theme: Clue Symmetry and Logic

Author/Opus: This is the 86th puzzle from our contributing puzzlemaster Murat Can Tonta.

Rules: Variation of Yajilin. Place the twelve pentominoes into empty cells in the grid (rotations and reflections allowed). No two pentominoes can share an edge. The numbered arrows indicate the number of cells that are parts of pentominoes in the given direction. Then draw a single closed loop (without intersections or crossings) through all remaining white cells as in a Yajilin.

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma.

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

Solution: PDF

Note: Follow this link for other variations of Yajilin and this link for classic Yajilin. 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.

PDF

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

Theme: One, Two

Author/Opus: This is the 245th puzzle from our contributing puzzlemaster Grant Fikes.

Rules: Standard Yajilin rules, except that instead of blackening single cells, blacken in dominoes (1×2 rectangles). Clues indicate the total number of dominoes (not the total number of cells) that are shaded in the given direction.

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma.

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

Solution: PDF

Note: Follow this link for other variations of Yajilin and this link for classic Yajilin. 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.

(View image directly for larger form.)

PDF

or solve online (using our beta test of Penpa-Edit tools in yajilin mode where left click shades squares, left click+drag draws lines and right click marks X’s; note that the default puzzle info is too long — even for an url shortener — so copy and paste all the text in this file into the “Load” option in the upper-right of the penpa-edit interface to access.)

Theme: Clue Symmetry and Logic (for TheSubro)

Author/Opus: This is the 158th puzzle from our contributing puzzlemaster Serkan Yürekli.

Rules: This puzzle combines four loop varieties commonly featured at GMPuzzles: Balance Loop (upper left), Yajilin (upper right), Castle Wall (lower left), and Masyu (lower right).

Draw a single, non-intersecting loop throughout all four quadrants. The loop may enter and exit the different quadrants as many times as needed.

The standard rules for each puzzle type are true for each quadrant, with these additional considerations:

Balance Loop: Use the entire length of segments (including parts of the segments that extend into an adjacent quadrant) when determining the balanced/unbalanced status of a circle clue.

Yajilin: The arrow clues refer only to shaded cells within the Yajilin quadrant. The loop must occupy all cells adjacent to a shaded cell, even in an adjacent quadrant.

Castle Wall: Number clues only apply within the grid and DO NOT include any line segments that cross the bold border with another grid or any segments in other quadrants. (Another way to say this is that the Castle Wall clues refer to the number of thin lines crossed in the lower-left quadrant only.)

Masyu: Normal rules apply for white and black circles, but the path satisfying these rules can extend into an adjacent quadrant. (For example, a white circle can be passed through crossing a quadrant edge, provided it turns immediately on one side of the circle whether the turn is in the Masyu quadrant or in another quadrant.)

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma.

Solution: PDF

Time Standards (highlight to view): Grandmaster = 18:00, Master = 35:00, Expert = 1:10:00

PDF

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

Theme: Outside Clues

Author/Opus: This is the 155th puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: Standard Yajilin rules, except that instead of blackening single cells, blacken in dominoes (1×2 rectangles). Clues indicate the total number of dominoes (not the total number of cells) that are shaded in the given direction.

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma.

Time Standards (highlight to view): Grandmaster = 5:00, Master = 7:30, Expert = 15:00

Solution: PDF; a solution video is available here.

Note: Follow this link for other variations of Yajilin and this link for classic Yajilin. 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.