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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 and a number entry mode.)

Theme: Eight 8s

Author/Opus: This is the 1st puzzle from guest contributor Shinichi Aoki.

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:

Answer String: For each cell in the marked rows/columns, enter the length of the snake it belongs to. Enter just the last digit for any two-digit number. This example has the key “33553,44664”.

Time Standards (highlight to view): Grandmaster = 3:15, Master = 5:30, Expert = 11:00

Solution: PDF

Note: Follow this link for other 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: X Box

Author/Opus: This is the 2nd puzzle from guest contributor Takeya Saikachi.

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:

Answer String: For each cell in the marked rows/columns, enter the length of the snake it belongs to. Enter just the last digit for any two-digit number. This example has the key “33553,44664”.

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

Solution: PDF

Note: Follow this link for other 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: XOXOXO (+ Antisymmetry)

Author/Opus: This is the 4th puzzle from guest contributor Nikolai Beluhov.

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:

Answer String: For each cell in the marked columns, enter the length of the snake it belongs to. Enter just the last digit for any two-digit number. This example has the key “33553,44664”.

Time Standards (highlight to view): Grandmaster = 11:30, Master = 17:30, Expert = 35:00

Solution: PDF

Note: Follow this link for other Snake puzzles.

(View image directly for larger form.)

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 letter entry mode.)

Theme: Logical

Author/Opus: This is the 249th puzzle from our contributing puzzlemaster Grant Fikes.

Rules: Variation of Pentominous rules. Divide this grid into 45 pentominoes each containing 5 cells. Pentominoes with the same shape (including rotations/reflections) cannot share an edge.
Some borders between pentominoes are already drawn.

Answer String: Enter the letter associated with the pentomino occupying each cell in the marked row from left to right, followed by a comma, followed by the marked column from top to bottom. Use CAPITAL LETTERS!

Time Standards (highlight to view): Grandmaster = 8:00, Master = 10:30, Expert = 21:00

Solution: PDF; a solution video is available here.

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.

(View image directly for larger form.)

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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 and a number entry mode.)

Theme: One is the Loneliest Fillomino?

Author/Opus: This is the 248th puzzle from our contributing puzzlemaster Grant Fikes.

Rules: Standard Fillomino rules.

Answer String: For each cell in the marked rows/columns, enter the area of the polyomino it belongs to. Enter just the last digit for any two-digit number. Start with the 10th row, followed by a comma, followed by the 17th row.

Time Standards (highlight to view): Grandmaster = 5:15, Master = 8:30, Expert = 17:00

Solution: PDF

Note: Follow this link for other classic Fillomino. 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 and in Fill o’ Fillomino by Grant Fikes.

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 Spiral Galaxy (the pattern of galaxies is a double spiral as shown here)

Author/Opus: This is the 25th puzzle from our contributing puzzlemaster Carl Worth.

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.

Answer String: Enter the number of cells in each connected group (between bold lines) in the marked rows. Separate each row’s entry from the next with a comma. The example has the answer “52,11131”.

Time Standards (highlight to view): Grandmaster = 10:30, Master = 17:00, Expert = 34:00

Solution: PDF

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 puzzles will soon be found in The Art of Puzzles 2.

(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 and a shading mode.)

Theme: Astronomical Clock

Author/Opus: This is the 26th puzzle from our contributing puzzlemaster John Bulten.

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.

Answer String: Enter the number of cells in each connected group (between bold lines) in the marked columns. Separate each column’s entry from the next with a comma. The example (using rows) has the answer “52,11131”.

Time Standards (highlight to view): Grandmaster = 6:15, Master = 10:15, Expert = 20:30

Solution: PDF

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 puzzles will soon be found in The Art of Puzzles 2.

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: Logical

Author/Opus: This is the 160th puzzle from our contributing puzzlemaster Serkan Yürekli.

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.

Answer String: Enter the number of cells in each connected group (between bold lines) in the marked rows. Separate each row’s entry from the next with a comma. The example has the answer “52,11131”.

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

Solution: PDF; a solution video is 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 puzzles will soon be found in The Art of Puzzles 2.

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: When Will the Solution Be Clear?

Author/Opus: This is the 159th puzzle from our contributing puzzlemaster Serkan Yürekli.

Rules: Standard Spiral Galaxies rules.

[Copying the rules here as this is the first week: Divide the grid along the indicated lines into connected regions – “galaxies” – with rotational symmetry. Each cell must belong to one galaxy, and each galaxy must have exactly one circle at its center of rotational symmetry.]

Answer String: Enter the number of cells in each connected group (between bold lines) in the marked rows. Separate each row’s entry from the next with a comma. The example has the answer “2131,331”.

Time Standards (highlight to view): Grandmaster = 5:00, Master = 6:30, Expert = 13:00

Solution: PDF; a solution video is 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 puzzles will soon be found in The Art of Puzzles 2.

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: Logical

Author/Opus: This is the 3rd puzzle from guest contributor Dan Katz.

Rules: Standard Spiral Galaxies rules.

[Copying the rules here as this is the first week: Divide the grid along the indicated lines into connected regions – “galaxies” – with rotational symmetry. Each cell must belong to one galaxy, and each galaxy must have exactly one circle at its center of rotational symmetry.]

Answer String: Enter the number of cells in each connected group (between bold lines) in the marked rows. Separate each row’s entry from the next with a comma. The example has the answer “2131,331”.

Time Standards (highlight to view): Grandmaster = 1:20, Master = 2:30, Expert = 5:00

Solution: PDF

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 puzzles will soon be found in The Art of Puzzles 2.