(This is a bonus “second” puzzle that is not connected to the usual Monday-Saturday week difficulty.)

PDF

or solve online (using our beta test of Penpa-Edit tools in edgex mode where left click+drag draws lines and right click marks X’s)

Theme: No Four in a Row

Author/Opus: This is the 2nd puzzle from guest contributor Matej Uher.

Rules: Standard Slitherlink rules. Also, the letters X and O stand for two different digits from 0 – 3.

Difficulty: 3 stars

Time Standards (highlight to view): Grandmaster = 2:45, Master = 4:00, Expert = 8:00

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

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.

PDF

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

Author/Opus: This is the 1st puzzle from guest contributor Matej Uher.

Rules: Place either an ‘X’ or an ‘O’ into each empty cell so that four consecutive ‘X’s or ‘O’s do not appear horizontally, vertically, or diagonally.

Difficulty: 2 stars

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

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

Note: Follow this link for other Number Placement puzzles.

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)

Author/Opus: This is the 10th puzzle from guest contributor Takeya Saikachi.

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: 3 stars

Time Standards (highlight to view): Grandmaster = 2:45, Master = 4:15, Expert = 8:30

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

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.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between a composite mode for line/edge drawing and a number entry mode.)

Theme: Noughts and Crosses

Author/Opus: This is the 29th puzzle from guest contributor Joseph Howard.

Rules: Divide the grid along the boundary lines so that every cell belongs to a snake. A snake is a one-cell-wide path at least two cells long that does not touch itself, not even diagonally. Circled cells must be at one of the ends of a snake. A snake may contain one circled cell, two circled cells, or no circled cells at all. Numbered cells must be part of a snake with a length of exactly that number of cells. A snake may contain one number, multiple identical numbers, or no numbers at all. Two snakes of the same length cannot touch each other horizontally or vertically. Cells with an X cannot be an end of a snake.

Also see this example:

Difficulty: 4.5 stars

Time Standards (highlight to view): Grandmaster = 9:30, Master = 14:00, Expert = 28:00

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

Note: Follow this link for more Snake Pit puzzles. Follow these links for other Fillomino or Snake puzzles.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between a composite mode for line/edge drawing and a number entry mode.)

Theme: Twins

Author/Opus: This is the 210th puzzle from our contributing puzzlemaster Murat Can Tonta.

Rules: Divide the grid along the boundary lines so that every cell belongs to a snake. A snake is a one-cell-wide path at least two cells long that does not touch itself, not even diagonally. Circled cells must be at one of the ends of a snake. A snake may contain one circled cell, two circled cells, or no circled cells at all. Numbered cells must be part of a snake with a length of exactly that number of cells. A snake may contain one number, multiple identical numbers, or no numbers at all. Two snakes of the same length cannot touch each other horizontally or vertically. Cells with an X cannot be an end of a snake.

Also see this example:

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 2:00, Master = 3:45, Expert = 7:30

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

Note: Follow this link for more Snake Pit puzzles. Follow these links for other Fillomino or Snake puzzles.

PDF

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

Theme: Zero

Author/Opus: This is the 341st puzzle from our managing editor Serkan Yürekli.

Rules: Standard Kakuro Rules, except that the allowed digit range is 0-9.

Difficulty: 4 stars

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

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

Note: Follow this link for classic Kakuro and this link for Kakuro variations. More Kakuro puzzles can be found in Kakuro and Variations by Serkan Yürekli and in The Art of Puzzles 2.

PDF

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

Theme: Antisymmetry

Author/Opus: This is the 217th puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: Standard Statue Park rules. Also, the numbers in the black circles show the number of spaces not occupied by pentominoes in orthogonally and diagonally adjacent cells. The numbers in the white circles show the number of spaces occupied by pentominoes in orthogonally and diagonally adjacent cells.

Difficulty: 4.5 stars

Time Standards (highlight to view): Grandmaster = 11:00, Master = 16:00, Expert = 32:00

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

Note: Follow this link for other classic Statue Park and this link for Statue Park variations. If you are new to this puzzle type, here are our easiest Statue Parks to get started on. More Statue Park puzzles can be found in the ebook Statue Park by Murat Can Tonta.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between shading mode and the composite Yajilin mode where left click marks cells, right click marks dots in cells or X’s on edges, left click+drag draws lines.)

Theme: 1-7

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

Rules: Standard Tapa rules. Also, similar to Nurikabe, each Tapa clue cell is part of an island of horizontally and vertically connected white cells and the area of the island must be one of the numbers in the clue (as an example, if a clue is 1 5, then the island containing that clue must be either 1 cell or 5 cells large). Islands are allowed to touch diagonally. No island can contain more than one number clue cell, but there may be islands without any number clues in the grid.

Difficulty: 2 stars

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

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

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

This year, we started posting 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 is a new Star Battle variation from puzzlemaster Murat Can Tonta; more of this variant will be in our upcoming Star Battle 2 e-book from JinHoo Ahn and Murat Can Tonta.

PDF

(view directly for a larger image)

or solve online (using our beta test of Penpa-Edit tools where a single star in gray means two stars but the standard Star Battle interface is used; if you prefer seeing 1 versus 2 objects, here is an alternate formatting using mines that allows for that.)

Theme: Stars

Author/Opus: This is the 208th puzzle from our contributing puzzlemaster Murat Can Tonta.

Rules: Standard Star Battle rules with three stars per row, column, and region. Also, there are some shaded cells in the grid and those cells either contain two stars or none. (In a gray cell with two stars, none of the adjacent cells sharing an edge or corner can have any stars.)

See also this example:

Difficulty: 5 stars

Time Standards (highlight to view): Grandmaster = 10:30, Master = 23:30, Expert = 47:00

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

Note: Follow this link for other classic Star Battles and this link for Star Battle variations. If you are new to this puzzle type, here are our easiest Star Battles to get started on. More Star Battle puzzles can be found in The Art of Puzzles, in the books Star Battle by JinHoo Ahn and Star Battle 2 by JinHoo Ahn and Murat Can Tonta, and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between a composite mode for line/edge drawing and a shading mode.)

Theme: Double Ring

Author/Opus: This is the 392nd puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Variation of Spiral Galaxies. In addition to the standard rules, some circles are shaded gray and must belong to galaxies containing two gray circles, not one, with the circles in rotationally symmetric spots for those galaxies.

Difficulty: 4.5 stars

Time Standards (highlight to view): Grandmaster = 7:00, Master = 13:15, Expert = 26:30

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

Note: Follow this link for classic Spiral Galaxies puzzles on this website and this link for variations on Spiral Galaxies puzzles. If you are new to this puzzle type, here are our easiest Spiral Galaxies Puzzles to get started on. More Spiral Galaxies can be found in The Art of Puzzles 2.