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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: Antisymmetry

Author/Opus: This is the 20th puzzle from guest contributor Salih Alan.

Rules: Shade some empty cells black so that each number indicates the total count of white cells connected vertically and horizontally to that number including the numbered cell itself. Black cells cannot share an edge, and all white cells must belong to a single connected group.

Also see this example:

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 more Kuromasu puzzles. More Kuromasu can be found in Grandmaster Puzzles Quarterly Vol. 3.

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: Twins

Author/Opus: This is the 14th puzzle from guest contributor Sam Cappleman-Lynes.

Rules: Shade some empty cells black so that each number indicates the total count of white cells connected vertically and horizontally to that number including the numbered cell itself. Black cells cannot share an edge, and all white cells must belong to a single connected group.

Also see this example:

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 1:45, Master = 2:30, Expert = 5:00

Solution: PDF and solving video.

Note: Follow this link for more Kuromasu puzzles. More Kuromasu can be found in Grandmaster Puzzles Quarterly Vol. 3.

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: Think Inside the Box

Author/Opus: This is the 426th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Spiral Galaxies 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 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.

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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: Multiples of 3

Author/Opus: This is the 62nd puzzle from our contributing puzzlemaster JinHoo Ahn.

Rules: Shade some empty cells black so that each number indicates the total count of white cells connected vertically and horizontally to that number including the numbered cell itself. Black cells cannot share an edge, and all white cells must belong to a single connected group.

Also see this example:

Difficulty: 1 star

Time Standards (highlight to view): Grandmaster = 1:00, Master = 1:15, Expert = 2:30

Solution: PDF and solving video.

Note: Follow this link for more Kuromasu puzzles. More Kuromasu can be found in Grandmaster Puzzles Quarterly Vol. 3.

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: Surrounded by 258

Author/Opus: This is the 9th puzzle from guest contributor William Hu.

Rules: Standard Cave rules.

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 3:45, Master = 4:45, Expert = 9:30

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.

(view directly for a larger image)

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

Theme: In Tux

Author/Opus: This is the 91st puzzle from our contributing puzzlemaster John Bulten.

Rules: Standard Pentominous rules.

Difficulty: 4 stars

Time Standards (highlight to view): Grandmaster = 7:15, Master = 10:15, Expert = 20:30

Solution: PDF and solving video.

Note: Follow this link for other Pentominous puzzles. If you are new to this puzzle type, here are our easiest Pentominous to get started on. More Pentominous puzzles can be found in the Plenty o’ Pentominous series by Grant Fikes 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, a letter entry mode, and a shading mode.)

Theme: Four

Author/Opus: This is the 377th puzzle from our managing editor Serkan Yürekli.

Rules: Standard Pentominous rules. Additionally, there are some gray cells that do not contain any pentominoes. The numbers in these gray cells indicate how many pentomino regions are present in the 8 neighboring cells.

Difficulty: 3.5 stars

Time Standards (highlight to view): Grandmaster = 6:00, Master = 7:30, Expert = 15:00

Solution: PDF and solving video.

Note: Follow this link for other Pentominous puzzles. If you are new to this puzzle type, here are our easiest Pentominous to get started on. More Pentominous puzzles can be found in the Plenty o’ Pentominous series by Grant Fikes 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, a letter entry mode, and a shading mode.)

Theme: 4 Pairs of Clues

Author/Opus: This is the 56th puzzle from our contributing puzzlemaster JinHoo Ahn.

Rules: Standard Pentominous rules.

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 2:15, Master = 4:00, Expert = 8:00

Solution: PDF and solving video.

Note: Follow this link for other Pentominous puzzles. If you are new to this puzzle type, here are our easiest Pentominous to get started on. More Pentominous puzzles can be found in the Plenty o’ Pentominous series by Grant Fikes 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, a letter entry mode, and a shading mode.)

Theme: I Go Undercover

Author/Opus: This is the 18th puzzle from guest contributor Salih Alan.

Rules: Standard Pentominous rules.

Difficulty: 2 stars

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

Solution: PDF and solving video.

Note: Follow this link for other Pentominous puzzles. If you are new to this puzzle type, here are our easiest Pentominous to get started on. More Pentominous puzzles can be found in the Plenty o’ Pentominous series by Grant Fikes 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, a letter entry mode, and a shading mode.)

Theme: Loss

Author/Opus: This is the 387th puzzle from our contributing puzzlemaster Grant Fikes.

Rules: Variation of Pentominous rules. Some borders between pentominoes are already drawn.

Difficulty: 2 stars

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

Solution: PDF and solving video.

Note: Follow this link for other Pentominous puzzles. If you are new to this puzzle type, here are our easiest Pentominous to get started on. More Pentominous puzzles can be found in the Plenty o’ Pentominous series by Grant Fikes and Murat Can Tonta and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.