PDF

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

Theme: Logical

Author/Opus: This is the 1st puzzle from guest contributor Ravi Kumar Macherla who also contributed several Masyu to the book “The Art of Puzzles”. You can find more of Ravi’s puzzles on his relatively new blog site.

Rules: Place each of the indicated shapes into the grid (rotations allowed, but not reflections) so that no two shapes touch even at a corner. Numbers outside the grid indicate the product of the lengths of all white cell groups in that row/column. Or see here:

Answer String: Enter the number of cells in each group (both black and white) in order in the marked rows/columns. In the example, this answer is “231,1221”

Time Standards (highlight to view): Grandmaster = 4:15, Master = 7:00, Expert = 14:00

Solution: PDF

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 47th puzzle from our contributing puzzlemaster Serkan Yürekli.

Rules: Standard Araf rules. Also, no two regions with the same size can share an edge. (Note: this is the same rule as in Fillomino puzzles where no equal size polyominoes can touch.)

Answer String: Enter the number of cells in each connected group (between bold lines) in the marked rows.

Time Standards (highlight to view): Grandmaster = 4:00, Master = 7:00, Expert = 14:00

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.

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: Four Y Intersections

Author/Opus: This is the 24th puzzle from our contributing puzzlemaster Prasanna Seshadri.

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).

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 = 3:15, Master = 5:00, Expert = 10:00

Solution: PDF; a solution video is available here.

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

PDF

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

Theme: Clue Symmetry and Logic

Author/Opus: This is the 22nd puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: Draw vertical/horizontal lines between dots to divide the grid into regions. A region may contain at most one number, equal to the area of the region. No region may cover a 2×2 area. Some dots are “heavy” and have 3 or 4 lines connected to them. Black circles indicate heavy dots with exactly three lines; white circles indicate heavy dots with four lines. Not all heavy dots are given, but there can be no heavy dots orthogonally adjacent to the indicated ones. In other words, there may be only 2 lines from any unmarked dot adjacent to a white/black circle (these dots are gray in the example).

Answer String: Enter the length of groups of white cells in the same area in the marked rows. For this example, the answer is “11212, 1132”

Time Standards (highlight to view): Grandmaster = 8:30, Master = 14:00, Expert = 28:00

Solution: PDF; a solution video is available here.

Note: This is a new puzzle style, so it is recommended to carefully review and solve the example first to get used to the thinking and all the rules.

PDF

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

Theme: No Givens

Author/Opus: This is the 5th puzzle from guest contributor Hans van Stippent.

Note: we’ve been holding onto this puzzle for awhile; it was inspired by last year’s USPC Thermo-Skyscrapers puzzle and, by adding in the sudoku constraints, makes a nice challenge before this weekend’s US Sudoku Qualifying Test.

Rules: Standard Thermo-Sudoku rules. Also, any digits in the thermometer shapes outside of the grid are Skyscraper clues, representing the number of buildings seen inside the grid in that direction as in a regular Skyscrapers puzzle. (Note: digits in a thermometer must be strictly increasing even when outside the grid, so do not repeat any digits within a thermometer.)

Answer String: Enter the 1st row from left to right, followed by a comma, followed by the 6th row from left to right. Note: only enter the 9 digits inside the grid in these rows, not any of the outside skyscraper clues.

Time Standards (highlight to view): Grandmaster = 5:30, Master = 9:30, Expert = 19:00

Solution: PDF

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.

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 6th 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 1-6 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 4th row from left to right, followed by a comma, followed by the 5th 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 = 6:00, Master = 9:00, Expert = 18:00

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.

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 5th 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 6th row from left to right.

Time Standards (highlight to view): Grandmaster = 4:45, Master = 6:00, Expert = 12:00

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.

PDF

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

Theme: Near Maximal Difficulty with Near Minimal Givens

Author/Opus: This is the 101st puzzle from our contributing puzzlemaster Grant Fikes.

Rules: Place a number into each cell so that each region contains the numbers 1 to N, where N is the size of the region. A cell with the number M must have at least M cells between it and any other instance of the same number M in that row or column.

Answer String: Enter the numbers in the marked rows in order from left to right, separating the rows with a comma. Start with the 5th row, followed by a comma, followed by the 9th row.

Time Standards (highlight to view): Grandmaster = 5:15, Master = 9:30, Expert = 19:00

Solution: PDF; a solution video is available here.

PDF

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

Theme: Man Made Out of Stars

Author/Opus: This is the 175th puzzle from Thomas Snyder aka Dr. Sudoku.

Rules: Standard Star Battle rules. Two stars per row, column, and region.

Answer String: For each row from top to bottom, enter the number of the first column from the left where a star appears. If the number has two digits, just enter the unit’s digit (i.e. column “10” would be entered as 0). Enter these numbers as a single string with no separators.

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

Solution: PDF

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

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 number entry mode, and shading for this variation.)

Theme: Clue Symmetry and Logic

Author/Opus: This is the 21st puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: Standard Fillomino rules. Also, it must be possible to shade some polyominoes black so that no bordering polyominoes are the same color (in other words, the grid must allow a two-color shading). Also, see this example:

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 2nd row, followed by a comma, followed by the 7th column.

Time Standards (highlight to view): Grandmaster = 4:30, Master = 8:00, Expert = 16:00

Solution: PDF; a solution video is available here.

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.