PDF

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

Theme: Antisymmetry

Author/Opus: This is the 9th puzzle from guest contributor Tapio Saarinen. You can find more of Tapio’s puzzles on his blog.

Rules: Standard Nurikabe rules.

Answer String: Enter the length in cells of each of the black segments (the unnumbered, connected “ocean”) from left to right for the marked rows. Separate each row’s entry from the next with a comma.

Time Standards (highlight to view): Grandmaster = 1:45, Master = 2:15, Expert = 4:30

Solution: PDF

Note: Follow this link for other classic Nurikabe. If you are new to this puzzle type, here are our easiest Nurikabes to get started on.

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: Digit Series

Author/Opus: This is the 224th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: (Standard Balance Loop rules.) Draw a single, non-intersecting loop that passes through all circled cells. All white circles must have equal segment lengths on both sides of the circle before turning. All black circles must have unequal segment lengths on both sides of the circle before turning. Numbers indicate the sum of the segment lengths on both sides of the circle.
Also, see 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. This example has the key “11,311”.

Time Standards (highlight to view): Grandmaster = 4:00, Master = 8:00, Expert = 16:00

Solution: PDF

Note: Follow this link for other Balance Loops.

PDF

or solve online (using our beta test of Penpa-Edit tools; in default linex mode: left-click+drag draws line, right click marks X on edge)

Theme: 24-7-365

Author/Opus: This is the 2nd puzzle from guest contributor Bryce Herdt (the 1st was his winning submission for our first hidden contest).

Rules: Draw a single loop in the grid which may cross itself orthogonally, but otherwise does not touch or retrace itself. The clue numbers to the left/right of the rows indicate the number of squares visited by the nearest section of the loop that travels horizontally in the rows. The clue numbers to the top/bottom of the columns indicate the number of squares visited by the nearest section of the loop that travels vertically in the columns.

Also, see this example:

Answer String: Enter the number of empty squares for each row from top to bottom, followed by a comma, and then the number of turns for each row from top to bottom. This example has the key “100000,422224”.

Time Standards (highlight to view): Grandmaster = 3:45, Master = 6:45, Expert = 13:30

Solution: PDF

Note: Follow this link for other Round Trip puzzles. Some more Round Trip puzzles can be found in the book Loop Variety Collection by Ashish Kumar and Murat Can Tonta.

PDF

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

Theme: Logical

Author/Opus: This is the 223rd puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Yajilin rules.

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 = 2:00, Master = 5:15, Expert = 10:30

Solution: PDF; a solution video is 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.

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: Logical

Author/Opus: This is the 26th puzzle from our contributing puzzlemaster Tom Collyer.

Rules: Standard Masyu rules.

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 classic Masyu. If you are new to this puzzle type, here are our easiest Masyu to get started on.

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: Clue Symmetry and Logic

Author/Opus: This is the 71st puzzle from our contributing puzzlemaster Serkan Yürekli.

Rules: Standard Castle Wall rules.

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 = 0:30, Master = 1:15, Expert = 2:30

Solution: PDF

Note: You can find other Castle Walls here.

PDF

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

Theme: Self-Titled

Author/Opus: This is the 222nd puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Thermo-Sudoku rules.

Answer String: Enter the 8th row from left to right, followed by a comma, followed by the 3rd column from top to bottom.

Time Standards (highlight to view): Grandmaster = 9:45, Master = 12:45, Expert = 25:30

Solution: PDF

Note: Follow this link for more Thermo-Sudoku puzzles. If you are new to this puzzle type, here are our easiest Thermo-Sudoku to get started on. More Thermo-Sudoku puzzles can be found in The Art of Sudoku 2.

PDF

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

Theme: Double Crossed

Author/Opus: This is the 5th puzzle from guest contributor Swaroop Guggilam.

Rules: Standard Arrow Sudoku rules.

Answer String: Enter the 4th row from left to right, followed by a comma, followed by the 9th row from left to right.

Time Standards (highlight to view): Grandmaster = 6:30, Master = 9:30, Expert = 19:00

Solution: PDF

Note: Follow this link for more Arrow Sudoku. If you are new to this puzzle type, here are our easiest Arrow Sudoku to get started on. More Arrow Sudoku puzzles can be found in The Art of Sudoku 2.

PDF

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

Theme: Fountain

Author/Opus: This is the 221st puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Arrow Sudoku rules.

Answer String: Enter the 5th row from left to right, followed by a comma, followed by the 9th row from left to right.

Time Standards (highlight to view): Grandmaster = 4:00, Master = 5:00, Expert = 10:00

Solution: PDF

Note: Follow this link for more Arrow Sudoku. If you are new to this puzzle type, here are our easiest Arrow Sudoku to get started on. More Arrow Sudoku puzzles can be found in The Art of Sudoku 2.

PDF

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

Theme: Level Thermometers

Author/Opus: This is the 2nd puzzle from guest contributor Ashish Kumar.

Rules: Standard Thermo-Sudoku rules.

Answer String: Enter the 2nd column from top to bottom, followed by a comma, followed by the 8th column from top to bottom.

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

Solution: PDF

Note: Follow this link for more Thermo-Sudoku puzzles. If you are new to this puzzle type, here are our easiest Thermo-Sudoku to get started on. More Thermo-Sudoku puzzles can be found in The Art of Sudoku 2.