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: Connected Logic

Author/Opus: This is the 1st puzzle from guest contributor Bobby Liu.

Rules: Standard Slitherlink rules. Also, there are four regions (in gray) in the two grids that are portals. All edges that touch any gray squares must match across grids (without rotation or reflection). For identical shapes, it is not known which positions are matched (for example, the ring in the upper left of the first puzzle could be in either the upper left or lower right of the second puzzle).

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 = 18:00, Master = 30:00, Expert = 1:00:00

Solution: PDF; a solution video is available here.

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.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between a shape/star placement mode and linex mode where left click+drag draws lines and right click marks X’s)

Theme: Relay of Logic

Author/Opus: This is the 28th puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: Standard Star Battle rules (ignore the shading). Then turn every star in a gray region into a black circle and every star in a white region into a white circle, and solve again as a standard Masyu puzzle. Ignore the region boundaries when drawing the Masyu loop.

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma.

Time Standards (highlight to view): Grandmaster = 2:00, Master = 3:00, Expert = 6:00

Solution: PDF

Note: Follow this link for other classic Star Battles and this link for other classic Masyu.

PDF

or solve online (using our beta test of Penpa-Edit tools in linex mode where left click+drag draws lines and right click marks X’s on edges)

Theme: Logical

Author/Opus: This is the 26th puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: In this variation of Tapa, the wall is in the form of a single non-intersecting loop. Clues inside the grid represent the number of neighboring cells visited by the loop; if there is more than one number in a cell, each number should be represented with a separate loop segment. There is no 2×2 rule of Tapa in this puzzle. This example image should help:

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. Separate each row’s entry with a comma. For the example, this would be “11,12”.

Time Standards (highlight to view): Grandmaster = 0:45, Master = 1:40, Expert = 3:20

Solution: PDF

Note: Follow this link for other Tapa-Like Loop puzzles. If you are new to this puzzle type, here are our easiest Tapa puzzles to get started on.

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 with a composite mode for line/edge drawing.)

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 with a composite mode for line/edge drawing.)

Theme: Clue Symmetry and Logic

Author/Opus: This is the 23rd 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, one in a yellow circle (>) and one in a red circle (<). Each region must have an area that is strictly between those numbers. 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 = 3:00, Master = 4:45, Expert = 9:30

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 with a composite mode for line/edge drawing.)

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.

PDF

or solve online (using our beta test of Penpa-Edit tools. Use left click to place 1 or 2 mines, right click (in cell) to mark unused, right click (on edge/corner) to mark a note; hitting tab will also enable a shading mode. If you want more solving options, turn off Penpa-Lite option.)

Theme: Symmetry and Logic (Note: this puzzle originally appeared in this year’s 24H Puzzle Championship.)

Author/Opus: This is the 45th puzzle from our contributing puzzlemaster Serkan Yürekli.

Rules: Place either 0, 1, or 2 mines into each empty cell so that each number represents the total count of mines in all neighboring cells, including diagonally adjacent cells. See also this example:

Answer String: For each cell in the marked columns, enter the number of mines (0, 1, 2) for each cell. Enter 0 if the cell is a number cell. Separate each column’s entry from the next with a comma. In the example (with marked rows), the answer is “022102,002000”.

Time Standards (highlight to view): Grandmaster = 6:00, Master = 9:30, Expert = 19:00

Solution: PDF

Note: Click here for other Double Minesweeper puzzles.

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.