PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between a shading mode and a mode to mark edges with an X.)

Theme: Easy as 123?

Author/Opus: This is the 16th puzzle from guest contributor Jonas Gleim.

Rules: Standard LITS rules.

Difficulty: 3.5 stars

Time Standards (highlight to view): Grandmaster = 4:30, Master = 7:15, Expert = 14:30

Solution: PDF and solving video.

Note: Follow this link for more variations of LITS and this link for classic LITS. If you are new to this puzzle type, here are our easiest LITS to get started on. More LITS puzzles can be found in LOTS O’ LITS by Grant Fikes and Prasanna Seshadri, in The Art of Puzzles 2, 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 shading mode and a mode to mark edges with an X.)

Theme: Jigsaw

Author/Opus: This is the 14th puzzle from guest contributor Chris Green.

Rules: Variation of LITS. Some cells or groups of cells are outlined and labeled with a letter. If any of these cells is shaded, then the tetromino shape must match the clued letter.

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 3:15, Master = 5:00, Expert = 10:00

Solution: PDF and solving video.

Note: Follow this link for more variations of LITS and this link for classic LITS. If you are new to this puzzle type, here are our easiest LITS to get started on. More LITS puzzles can be found in LOTS O’ LITS by Grant Fikes and Prasanna Seshadri, in The Art of Puzzles 2, and in our beginner-friendly collection Intro to GMPuzzles 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 ninth Sunday Stumper of 2022 is a Slitherlink (Switch) puzzle by Matej Uher, author of our new Slitherlink and Variations 2 book. Each clue here has to switch with one of its orthogonal neighbors, so it will be quite a challenge to find the complete loop.

(view directly for a larger image)

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to switch between edgex mode where left click+drag draws lines and right click marks X’s, and a shading and number entry mode to mark/update the switched clues.)

Theme: Knight’s Moves

Author/Opus: This is the 5th puzzle from guest contributor Matej Uher.

Rules: Standard Slitherlink rules. Also, each given clue has to switch its initial position with one of its adjacent neighbors.

Also, see this example:

Difficulty: 5 stars

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

Solution: PDF and solving video.

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 in edgex mode where left click+drag draws lines and right click marks X’s)

Theme: Columns

Author/Opus: This is the 11th puzzle from guest contributor Michael Tang.

Rules: Standard Slitherlink rules.

Difficulty: 3 stars

Time Standards (highlight to view): Grandmaster = 2:30, Master = 5:15, Expert = 10:30

Solution: PDF and solving video.

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 in edgex mode where left click+drag draws lines and right click marks X’s)

Theme: Pairs

Author/Opus: This is the 11th puzzle from guest contributor Eric Fox.

Rules: Standard Slitherlink rules.

Difficulty: 2 stars

Time Standards (highlight to view): Grandmaster = 1:30, Master = 2:00, Expert = 4:00

Solution: PDF and solving video.

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; use tab to shift between number entry and shading modes.)

Theme: Mystery Box

Author/Opus: This is the 12th puzzle from guest contributor Sam Cappleman-Lynes.

Rules: Place a number from 0 to 9 into each area so that no two areas that touch orthogonally share the same number. Wherever four areas meet at a point (marked with dots as a visual aid), the numbers in those areas must add up to 10.

Also, see this example:

Difficulty: 4.5 stars

Time Standards (highlight to view): Grandmaster = 14:45, Master = 21:00, Expert = 42:00

Solution: PDF and solving video.

Note: Follow this link for other less common Number Placement puzzles.

PDF

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

Theme: Lion Face

Author/Opus: This is the 17th puzzle from guest contributor Rajesh Kumar.

Rules: Standard Thermo-Sudoku rules.

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 2:45, Master = 5:00, Expert = 10:00

Solution: PDF and solving video.

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 and Masterpiece Sudoku Mix 2.

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: Spiral Galaxy

Author/Opus: This is the 10th puzzle from guest contributor Eric Fox.

Rules: Standard Aqre rules: Shade some cells so that all shaded cells form one connected group. Regions with numbers must contain the indicated count of shaded cells, and it is allowed to shade over the numbered cells. There may not exist a run of four or more consecutive shaded or unshaded cells horizontally or vertically anywhere in the grid.

See also this example:

Difficulty: 2.5 stars

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

Solution: PDF and solving video.

Note: Follow this link for more Aqre puzzles. If you are new to this puzzle type, here are our easiest Aqre to get started on. More Aqre puzzles are in Shading Variety Collection by Prasanna Seshadri.

PDF

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

Theme: Seven Times

Author/Opus: This is the 17th puzzle from guest contributor Salih Alan.

Rules: Standard Skyscrapers rules.

Difficulty: 2 stars

Time Standards (highlight to view): Grandmaster = 1:40, Master = 2:30, Expert = 5:00

Solution: PDF and solving video.

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

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: Tetrominoes

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

Rules: Standard Fillomino rules.

Difficulty: 1.5 stars

Time Standards (highlight to view): Grandmaster = 0:50, Master = 1:30, Expert = 3:00

Solution: PDF and solving video.

Note: Follow this link for classic Fillomino and this link for Fillomino variations. If you are new to this puzzle type, here are our easiest Fillomino puzzles to get started on. More Fillomino puzzles can be found in The Art of Puzzles, in Fill o’ Fillomino and Fill o’ Fillomino 2 by Grant Fikes, and in our beginner-friendly books Logic Puzzles 101 and Starter Pack 1: Fillomino.