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 fifth Sunday Stumper of 2022 is a combination of Arrow Sudoku and Thermo-Sudoku by Jonas Gleim.

PDF

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

Theme: Compass

Author/Opus: This is the 12th puzzle from guest contributor Jonas Gleim.

Rules: Standard Arrow Sudoku and Thermo-Sudoku rules.

Difficulty: 5 stars

Time Standards (highlight to view): Grandmaster = 18:00, Master = 25:00, Expert = 50:00

Solution: PDF and solving video.

Note: Follow this link for other classic Sudoku. If you are new to this puzzle type, here are our easiest Sudoku to get started on. More classic Sudoku puzzles can be found in The Art of Sudoku, The Art of Sudoku 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 edgex mode where left click+drag draws lines and right click marks X’s and a shading mode to mark inside and outside of loop.)

Theme: Centered Squares

Author/Opus: This is the 4th puzzle from guest contributor Matej Uher.

Rules: Standard Slitherlink rules. Also, an even number of cells in each row and in each column must be inside the loop.

Difficulty: 4.5 stars

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

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 shading mode and the linex mode where left click+drag draws lines and right click marks X’s)

Theme: Twister

Author/Opus: This is the 6th puzzle from guest contributor wormsofcan.

Rules: Standard Cave rules.

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 2:15, Master = 3:00, Expert = 6:00

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: Infinity

Author/Opus: This is the 15th puzzle from guest contributor Rajesh Kumar.

Rules: Standard Sudoku rules.

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 other classic Sudoku. If you are new to this puzzle type, here are our easiest Sudoku to get started on. More classic Sudoku puzzles can be found in The Art of Sudoku, The Art of Sudoku 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 shift between number entry and shading modes.)

Theme: Multiples of 2-3-4-5

Author/Opus: This is the 2nd puzzle from guest contributor Emin Erzurumluoğlu.

Rules: Fill each row and column of the grid with the digits 1 to 4 and two blackened cells. Numbers outside the grid indicate the sum of the digits between the two blackened cells in that row or column. Blackened cells are allowed to touch. Or see here.

Difficulty: 1.5 stars

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

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

Theme: Ones

Author/Opus: This is the 1st puzzle from guest contributor Stefan Liew.

Rules: Standard Castle Wall rules.

Difficulty: 1 star

Time Standards (highlight to view): Grandmaster = 0:25, Master = 0:45, Expert = 1:30

Solution: PDF and solving video.

Note: Follow this link for more Castle Wall puzzles. If you are new to this puzzle type, here are our easiest Castle Wall puzzles to get started on. More Castle Wall puzzles can be found in our beginner-friendly collection Intro to GMPuzzles as well as the larger collection Castle Wall, both by Serkan Yürekli.

PDF

or solve online (using our beta test of Penpa-Edit tools; in composite Star Battle mode a left click places a star, right click in a cell marks off the cell, and a right click on an edge or corner marks in a dot as a placement note.)

Theme: T Time

Author/Opus: This is the 371st puzzle from our contributing puzzlemaster Grant Fikes.

Rules: Standard Star Battle rules. One star per row, column, and region.

Difficulty: 1 star

Time Standards (highlight to view): Grandmaster = 0:25, Master = 0:45, Expert = 1:30

Solution: PDF and solving video.

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 collections Intro to GMPuzzles by Serkan Yürekli and Starter Pack 5: Star Battle by JinHoo Ahn.

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: Three of a Kind

Author/Opus: This is the 10th puzzle from guest contributor Roger Barkan.

Rules: Standard Cave rules.

Difficulty: 4.5 stars

Time Standards (highlight to view): Grandmaster = 8:15, Master = 14:00, Expert = 28:00

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; use tab to shift between shading mode and the linex mode where left click+drag draws lines and right click marks X’s)

Theme: Central Diamond

Author/Opus: This is the 1st puzzle from guest contributor Chandrachud Nanduri.

Rules: Standard Cave rules. (The puzzle is on a hexagonal grid and cells now see in a maximum of six possible directions.)

Difficulty: 3 stars

Time Standards (highlight to view): Grandmaster = 5:00, Master = 6:15, Expert = 12:30

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; use tab to shift between shading mode and the linex mode where left click+drag draws lines and right click marks X’s)

Theme: Primes

Author/Opus: This is the 4th puzzle from guest contributor Mark Sweep.

Rules: Standard Cave rules.

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 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.