Araf (Inequality) by Dan Katz

Araf by Dan Katz

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: Clue Symmetry and Logic

Author/Opus: This is the 1st puzzle from guest contributor Dan Katz.

Rules: Divide the grid into some regions formed of edge-adjacent squares. Each cell is part of one region, and each region should contain exactly two given numbers, one in a yellow circle (>) and one in a red circle (<). Each region must have an area that is strictly between those numbers. Note: This idea to "simplify" Araf puzzles comes from Prasanna Seshadri, whose example of this variation will appear tomorrow. Answer String: Enter the number of cells in each connected group (between bold lines) in the marked rows. Separate the rows with a comma.

Time Standards (highlight to view): Grandmaster = 1:20, Master = 3:00, Expert = 6:00

Solution: PDF

Note: Araf is a relatively new puzzle for us on GMPuzzles. Follow this link for other Araf. An example image for a “classic” Araf puzzle is here.

Araf by Thomas Snyder

Araf by Thomas Snyder

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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: Aisles

Author/Opus: This is the 177th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Divide the grid into some regions formed of edge-adjacent squares. Each cell is part of one region, and each region should contain exactly two given numbers. Each region must have an area that is strictly between those numbers (This means, for two number clues A and B with A < B, the area C fulfills A < C < B).

Araf Example

Answer String: Enter the number of cells in each connected group (between bold lines) in the marked rows. For the example above, this is “34,121111,4111”.

Time Standards (highlight to view): Grandmaster = 0:45, Master = 1:15, Expert = 2:30

Solution: PDF

Note: Araf is a relatively new puzzle for us on GMPuzzles. Follow this link for other Araf.

Slitherlink (Sheep and Wolves) by Grant Fikes

Slitherlink by Grant Fikes

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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: Symmetrical Clues (allowing for rotations and reflections)

Author/Opus: This is the 102nd puzzle from our contributing puzzlemaster Grant Fikes.

Rules: Standard Slitherlink rules. Also, there are some sheep (marked by a reflected 2 in blue) that must be inside the loop and some wolves (marked by a rotated 3 in red) that must be outside the loop.

(Note: the reflected/rotated digits in blue and red do not actually serve as loop clues meaning 2 and 3, just as sheep and wolves. We chose this presentation because the theme works better with the wackiness of some 2’s and 3’s even if it needs this extra note.)

Answer String: Enter the length in cells of each of the internal loop segments following the arrows for the marked rows, starting at the top. Separate each row’s entry with a comma.

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

Solution: PDF

Note: Follow this link for other Slitherlink variations and this link for classic Slitherlink. If you are new to this puzzle type, here are our easiest Slitherlink puzzles to get started on.

Battleships by Thomas Snyder

Battleships by Thomas Snyder

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or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between ship placement and shading modes. In ship placement mode, right click gives sea, left click gives circle/square, left click and drag for rounded ships.)

Theme: Logic and Near Symmetry (the row and column clues break into mostly symmetric groups)

Author/Opus: This is the 176th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Battleships rules. Use the indicated fleet.

Answer String: For each row from top to bottom, enter the number of the first column from the left where a ship segment appears (enter both digits if a two-digit number). If the row is empty, enter 0. Enter these numbers as a single string with no separators.

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

Solution: PDF

Note: Follow this link for other classic Battleships. If you are new to this puzzle type, here are our easiest Battleships to get started on.

Skyscrapers (Tight Fit) by Roland Voigt

Skyscrapers by Roland Voigt

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between Sudoku = big digits and Number candidate = small entries in the corners of cells.)

Theme: Equal Distribution and Symmetry of Clue Numbers

Author/Opus: This is the 2nd puzzle from guest contributor Roland Voigt.

Rules: Standard Skyscrapers rules. Also, some cells have been split into triangles, each of which must be filled with a number. In this puzzle, the numbers 1-5 must be placed in each row and column.

(The split cells are viewed in the order they are seen from a given direction, so the upper triangles are seen first from the left/top sides and the bottom triangles are seen first from the right/bottom sides.)

Answer String: Enter the 1st row from left to right, followed by a comma, followed by the 3rd row from left to right. Enter the split cells in the order they are seen from the left (the upper triangle before the lower triangle).

Time Standards (highlight to view): Grandmaster = 0:40, Master = 1:15, Expert = 2:30

Solution: PDF

Note: Follow this link for other classic Skyscrapers and this link for variations on Skyscrapers puzzles. If you are new to this puzzle type, here are our easiest Skyscrapers to get started on.

Skyscrapers by Roland Voigt

Skyscrapers by Roland Voigt

PDF

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

Theme: Equal Distribution and Symmetry of Clue Numbers

Author/Opus: This is the 1st puzzle from guest contributor Roland Voigt.

Rules: Standard Skyscrapers rules.

Answer String: Enter the 1st row from left to right, followed by a comma, followed by the 5th row from left to right.

Time Standards (highlight to view): Grandmaster = 0:40, Master = 1:15, Expert = 2:30

Solution: PDF

Note: Follow this link for other classic Skyscrapers. If you are new to this puzzle type, here are our easiest Skyscrapers to get started on.

Negative Tetromino by Serkan Yürekli

Negative Tetromino by Serkan Yürekli

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or solve online (using our beta test of Penpa-Edit tools in a composite mode for line/edge drawing)

Theme: Words

Author/Opus: This is the 36th puzzle from our contributing puzzlemaster Serkan Yürekli.

Rules: Divide the white cells into tetrominoes so that no two regions sharing an edge are the same tetromino (L, I, O, S, or T considering rotation and reflection). Regions may contain at most 1 cell with given letters; regions with such a cell CANNOT have the same tetromino shape as any of the letters in that cell. Also, see this example:

Negative Tetromino by Serkan Yürekli

Answer String: Enter the letter of the tetromino region for each cell in the two marked rows from left to right, separating the rows with a comma. Use CAPITAL LETTERS for L, I, O, S, and T.

Time Standards (highlight to view): Grandmaster = 1:15, Master = 2:30, Expert = 5:00

Solution: PDF

Sudoku by Thomas Snyder

Sudoku by Thomas Snyder

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

Theme: Desperately Seeking Seven (Note: the shading of the “7” shaped region is just for artistic purposes.)

Author/Opus: This is the 173rd puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Sudoku rules (no repeats in any rows, columns, or bold regions). The digit range is 1-7.

Answer String: Enter the 2nd row from left to right, followed by a comma, followed by the 5th row from left to right.

Time Standards (highlight to view): Grandmaster = 1:15, Master = 2:00, Expert = 4:00

Solution: PDF

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.

Fillomino (Symmetry) by Serkan Yürekli

Fillomino 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 and a number entry mode.)

Theme: Clue Symmetry and Logic

Author/Opus: This is the 35th puzzle from our contributing puzzlemaster Serkan Yürekli.

Rules: Standard Fillomino rules. Also, all polyominoes should have rotational symmetry as in this example:

Fillomino by Serkan Yürekli

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 1st row, followed by a comma, followed by the 3rd column.

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

Solution: PDF

Note: Follow this link for other classic Fillomino and this link for more variations on Fillomino puzzles. If you are new to this puzzle type, here are our easiest Fillomino puzzles to get started on.

Fillomino by Grant Fikes

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 number entry mode.)

Theme: Don’t Stop Solving Fillomino

Author/Opus: This is the 98th 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 1st row, followed by a comma, followed by the 10th row.

Time Standards (highlight to view): Grandmaster = 1:15, Master = 1:45, Expert = 3:30

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.