PDF

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

Theme: Offset Frame

Author/Opus: This is the 418th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Sudoku rules. Also, there are some numbered shapes that must be put into the grid. Shapes can be rotated, but cannot be reflected.

Difficulty: 4 stars

Time Standards (highlight to view): Grandmaster = 8:30, Master = 13:00, Expert = 26:00

Solution: PDF and solving video.

Note: Follow this link for other Shape Sudoku. More Shape Sudoku are in Masterpiece Sudoku Mix 8.

This variation from Dr. Sudoku will appear on the 8th round of the Sudoku Grand Prix opening August 5th and running through August 8th. This puzzle was created as the “example” puzzle for the style, and is a representative puzzle (in difficulty and style) to help prepare for the competition.

PDF

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

Theme: Boxes

Author/Opus: This is the 417th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Sudoku rules. Also, some numbers are given on the edges between two adjacent cells. Treating those cells as a two-digit number (reading left to right or top to bottom), the two-digit number must be a multiple of the clue. (For example, near a 7 clue, the two digits can be 14, 21, 28, 35, ….)

Difficulty: 4 stars

Time Standards (highlight to view): Grandmaster = 7:30, Master = 10:00, Expert = 20:00

Solution: PDF and solving video.

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; use tab to alternate between Sudoku number entry mode and a shading mode to manage the shape inventory.)

Theme: Goalkeeper

Author/Opus: This is the 374th puzzle from our managing editor Serkan Yürekli.

Rules: Standard Sudoku rules. Also, there are some numbered shapes that must be put into the grid. Shapes can be rotated, but cannot be reflected.

Difficulty: 1.5 stars

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

Solution: PDF and solving video.

Note: Follow this link for other Shape Sudoku. More Shape Sudoku are in Masterpiece Sudoku Mix 8.

(view directly for a larger image)

PDF

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

Theme: Even/Odd Trios

Author/Opus: This is the 235th puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: Standard Sudoku rules. Numbers do not repeat along any of the three directions in which the hexagonal cells share edges.

Difficulty: 2 stars

Time Standards (highlight to view): Grandmaster = 2:00, Master = 2:45, Expert = 5:30

Solution: PDF and solving video.

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.

This year, we started posting some extra difficult Sunday Stumpers, about once a month. These will be quite tough puzzles, but with a logical path to be found (and solution videos to help). This eleventh Sunday Stumper is a challenging (anti-)XV Sudoku by Murat Can Tonta.

PDF

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

Theme: Pairs

Author/Opus: This is the 214th puzzle from our contributing puzzlemaster Murat Can Tonta.

Rules: Standard Sudoku rules. Also, whenever the numbers in two adjacent cells sum to exactly 10 or 5, an X or V is placed on the edge between cells reflecting the Roman numerals for 10 or 5. All adjacent cells not marked with an X or V cannot add up to 10 or 5.

Difficulty: 5 stars

Time Standards (highlight to view): Grandmaster = 17:30, Master = 30:00, Expert = 1:00:00

Solution: PDF; a solution video is also available here.

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)

Author/Opus: This is the 212th puzzle from our contributing puzzlemaster Murat Can Tonta.

Rules: Standard Sudoku rules. Also, numbers cannot repeat in any cells separated by a chess knight’s move.

Difficulty: 3.5 stars

Time Standards (highlight to view): Grandmaster = 3:30, Master = 9:00, Expert = 18:00

Solution: PDF; a solution video is also available here.

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.

I was quite saddened to learn that Maki Kaji, founder of the puzzle company Nikoli, passed away last week from cancer. A lot of the news about the “Godfather of Sudoku” will focus on one puzzle, as Nikoli’s renaming of Number Place / Nanpure into “Sudoku” became the inspiration for the global craze. My own note of thanks and remembrance will be broader, about the many many different kinds of puzzles that came out of the community of Nikoli authors and publications that Maki helped to create, starting with the first Puzzle Communication Nikoli in the early 1980s.

I would not have gotten as passionate about logic puzzles if I hadn’t run into Nikoli’s hand-crafted puzzles in the mid 2000s. As I wrote to Maki Kaji back in 2011 about my history with Nikoli, after sharing dinner with him and other puzzle friends in San Francisco:
“I got a Nikoli Communication magazine, #112 I think, when I was at the World Puzzle Championship in 2005 in Eger, Hungary. This was my first international trip to solve puzzles, and my first experience seeing many foreign puzzle sources, but I knew very quickly that Nikoli was special.” I ordered hundreds of books and probably solved tens of thousands of Nikoli puzzles in the decade after first finding a Nikoli magazine. If I could have submitted puzzles to Nikoli, I would have. Nikoli’s set of publications and community building efforts, including a focus on simple, elegant, and visually interesting designs, continues to inspire us at GMPuzzles. We hope to someday influence the puzzle community as much as Maki Kaji did and his company still does.

Here is a Wordoku puzzle I wrote today to remember Maki Kaji:

PDF

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

Theme: Rest in Peace, Maki Kaji (1951-2021)

Author/Opus: This is the 389th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Place a letter from A, I, J, K, L, M, N, O, or the symbol ? into each cell so that no character repeats in any row, column, or bold region.

Solution: PDF