June 1st will be the reopening of GMPuzzles. In recent years we have had on weeks and off weeks, but with this relaunch we are planning to have content every week. Monday through Saturdays will be new puzzles, with increasing difficulty throughout the week. There will be a mix of variety weeks and single puzzle genre weeks. On Sundays we will be releasing solution images for all of the puzzles, as well as a solution video walkthrough for one of our puzzles. While these solutions have historically been “rewards” for our subscribers, we hope that sharing them more broadly will help expand our community and help people learn how to solve our hardest puzzles.

We’ll have info on some other changes soon; for now, enjoy this Countdown TomTom.

PDF

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

Theme: Countdown + 15 Spirals

Author/Opus: This is the 357th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard TomTom rules, using the integers 1-8.

Solution: PDF

Note: Follow this link for other TomTom. If you are new to this puzzle type, here are our easiest TomTom to get started on. More TomTom puzzles can be found in The Art of Puzzles, and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

(Note: This bonus puzzle is being posted today to mark the occasion of Prasanna’s birthday.)

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between a shading mode, a line-drawing mode with diagonal and straight options, and an edge marking mode to add x’s as needed.)

Theme: One Away from Thirty

Author/Opus: This is the 180th puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: Locate two snakes in the grid. Each snake must start from one of the gray circles, but has an unknown ending point. Black circles represent an interior cell of one of the snakes, and all black circles must be part of a snake. Each snake’s path is allowed to move vertically, horizontally, or diagonally between cells. An interior snake cell can only be adjacent to two other snake cells (including diagonally adjacent cells) and an end of the snake can only be adjacent to one other snake cell (including diagonally adjacent cells). The two different snakes must not share any adjacent cells.

There are some numbers outside the grid. These numbers indicate the number of vertical or horizontal edges (not corners) that snakes cross in that direction.

There are some letters inside the grid. For each distinct letter, exactly one of its instances is visited by one of the two snakes.

Also see this example:

Solution: PDF

Dear friends,

This weekend is the MIT Mystery Hunt and Grandmaster Puzzles is very happy to be a sponsor of this puzzle event in 2020.

If you are new to this site, there are lots of different fun genres of logic puzzles to explore and you can follow some of the links to the left to find these genres including our easiest puzzles to get started. The Intro to GMPuzzles and Logic Puzzles 101 books are some great titles to try as well.

As part of the pre-Hunt activities for the team I compete with, I created the attached puzzle set in the style of a Mystery Hunt puzzle. Like most puzzlehunt puzzles, it is missing some of the instructions you may want to have but I think you may still be able to figure it out. It has a final answer which is a word/phrase. We will post some hints and/or the answer in the coming weeks.

Puzzle PDF for A/B Testing

Teaser image 1 = Framed!:

Teaser image 2 = Easy as 1, 2, 3:

Solution: Puzzle solution packet; or full solution including steps to final message.

PDF

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

Theme: Empty Inside

Author/Opus: This is the 179th puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: Standard Sudoku rules. Additionally, the numbers outside the grid indicate the sum of the first N cells in that row/column from that direction, for some value of N from 1 to 9.

Answer String: Enter the 8th row from left to right, followed by a comma, followed by the 5th column from top to bottom.

Time Standards (highlight to view): Grandmaster = 12:00, Master = 18:00, Expert = 36:00

Solution: PDF

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

PDF

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

Theme: Clueless; World Puzzle Championship (WPC)

Author/Opus: This is the 41st puzzle from our contributing puzzlemaster Ashish Kumar.

Rules: Standard Thermo-Sudoku rules.

Answer String: Enter the 4th row from left to right, followed by a comma, followed by the 8th row from left to right.

Time Standards (highlight to view): Grandmaster = 8:00, Master = 11:30, Expert = 23:00

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)

Theme: Logical (originally in Ashish’s book “Enthralling Sudoku“)

Author/Opus: This is the 40th puzzle from our contributing puzzlemaster Ashish Kumar.

Rules: Standard Even/Odd Sudoku rules (i.e., cells with a square contain an even digit; cells with a circle contain an odd digit).

Answer String: Enter the 5th row from left to right, followed by a comma, followed by the 9th row from left to right.

Time Standards (highlight to view): Grandmaster = 7:00, Master = 9:30, Expert = 19:00

Solution: PDF

Note: Follow this link for more Even/Odd Sudoku puzzles. If you are new to this puzzle type, here are our easiest Even/Odd Sudoku to get started on. More Even/Odd Sudoku puzzles can be found in The Art of Sudoku 2 and Masterpiece Sudoku Mix 1.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between Sudoku number entry mode and a line mode to mark the snake.)

Theme: Clue Symmetry and Logic

Author/Opus: This is the 279th puzzle from our contributing puzzlemaster Serkan Yürekli.

Rules: Standard Sudoku rules. Additionally, locate a snake (a 1-cell wide path) that connects the gray circles marked with 1 and 9. The snake cannot touch itself, even diagonally. All cells marked with white circles must be part of the snake. Along the path, the snake must pass straight through any cell with an odd number from the sudoku, and must make a 90-degree turn in any cell with an even number from the sudoku.

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 = 5:15, Master = 9:00, Expert = 18:00

Solution: PDF

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

(view directly for a larger image)

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab key to alternate between loop drawing and letter entry modes)

Theme: Clue Symmetry and Logic

Author/Opus: This is the 277th puzzle from our contributing puzzlemaster Serkan Yürekli.

Rules: Place each of the given words into the grid, reading across or down; all words should interconnect, and all words formed in the grid must be from the list. Each given letter must be used by at least one word. Additionally, draw a Masyu loop: a single closed loop passing through each of the “O”s and otherwise using only unused squares. When passing through an “O”, the loop must go straight through and must make a 90 degree turn in at least one of the adjacent squares.

See also this example:

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 = 7:00, Master = 10:45, Expert = 21:30

Solution: PDF

Note: Follow this link for other Masyu variations and this link for classic Masyu. If you are new to this puzzle type, here are our easiest Masyu to get started on. More Masyu puzzles can be found in The Art of Puzzles.

(view directly for a larger image)

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)

Theme: Down the Middle

Author/Opus: This is the 161st puzzle from our contributing puzzlemaster Murat Can Tonta.

Rules: Standard Masyu rules.

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 = 3:15, Master = 4:45, Expert = 9:30

Solution: PDF

Note: Follow this link for other classic Masyu. If you are new to this puzzle type, here are our easiest Masyu to get started on. More Masyu puzzles can be found in The Art of Puzzles and in our beginner-friendly book Logic Puzzles 101.

PDF

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

Theme: S for Slitherlink

Author/Opus: This is the 5th puzzle from guest contributor Freddie Hand.

Rules: Variation of Slitherlink rules. Draw a set of eleven pentomino-shaped loops (i.e., all but one of the given shapes) consisting of vertical and horizontal segments between the dots. Numbers inside a cell indicate how many of the edges of that cell are part of the loops. The pentomino-shaped loops cannot be in adjacent cells that share an edge or corner, and may be rotated or reflected.

See also this example:

Answer String: For each marked row, enter the length in cells of each connected group inside the loops from left to right. Separate each row’s entry with a comma.

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

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. More Slitherlink puzzles can be found in The Art of Puzzles, Slitherlink and Variations, and our beginner-friendly book Logic Puzzles 101.