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: Noah’s Ark

Author/Opus: This is the 9th puzzle from guest contributor Roger Barkan.

Rules: Standard Cave rules.

Difficulty: 4 stars

Time Standards (highlight to view): Grandmaster = 5:45, Master = 9:15, Expert = 18:30

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

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: Sevens

Author/Opus: This is the 7th puzzle from guest contributor Michael Tang.

Rules: Standard Cave rules.

Difficulty: 3 stars

Time Standards (highlight to view): Grandmaster = 3:00, Master = 4:15, Expert = 8:30

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

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: All Threes

Author/Opus: This is the 27th puzzle from guest contributor Joseph Howard.

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

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 2:15, Master = 3:15, Expert = 6:30

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

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: Even

Author/Opus: This is the 8th puzzle from guest contributor Roger Barkan.

Rules: Standard Cave rules.

Difficulty: 2.5 stars

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

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

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: Fan

Author/Opus: This is the 7th puzzle from guest contributor William Hu.

Rules: Standard Cave rules.

Difficulty: 1 star

Time Standards (highlight to view): Grandmaster = 0:45, Master = 1:00, Expert = 2:00

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

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: Sun Rays

Author/Opus: This is the 7th puzzle from guest contributor Akash Doulani.

Rules: Standard Thermo-Sudoku rules.

Difficulty: 3.5 stars

Time Standards (highlight to view): Grandmaster = 4:45, Master = 8:30, Expert = 17:00

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

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.

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

Theme: Cosmos Redshift 7

Author/Opus: This is the 2nd puzzle from guest contributor Wei-Hwa Huang.

Rules: Standard Even/Odd Sudoku rules (i.e., cells with a square contain an even digit; cells with a circle contain an odd digit).

Difficulty: 3 stars

Time Standards (highlight to view): Grandmaster = 3:00, Master = 5:15, Expert = 10:30

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

Note: Follow this link for more Even/Odd Sudoku puzzles. If you are new to this puzzle type, here are our easiest Even/Odd Sudoku to get started on. More Even/Odd Sudoku puzzles can be found in The Art of Sudoku 2 and Masterpiece Sudoku Mix 1.

PDF

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

Theme: Rectangles

Author/Opus: This is the 3rd puzzle from guest contributor R. Kumaresan.

Rules: Standard Sudoku rules.

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 2:15, Master = 3:45, Expert = 7:30

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

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

Theme: Zigzag Frame

Author/Opus: This is the 9th puzzle from guest contributor Walker Anderson.

Rules: Standard Slitherlink rules.

Difficulty: 3.5 stars

Time Standards (highlight to view): Grandmaster = 3:30, Master = 6:30, Expert = 13:00

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

Theme: Inside Job

Author/Opus: This is the 1st puzzle from guest contributor Priyam Bhushan.

Rules: Standard Slitherlink rules. Also, numbers outside the grid show the number of separate loop segments visible in that direction. A segment of length N in a given direction is taken as a building of height N. Buildings of height N block the view of all buildings behind them of equal or lesser height.

See also this example:

Difficulty: 3 stars

Time Standards (highlight to view): Grandmaster = 3:45, Master = 5:15, Expert = 10:30

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.