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: Twos

Author/Opus: This is the 28th puzzle from guest contributor Joseph Howard.

Rules: Standard Castle Wall rules.

Difficulty: 4 stars

Time Standards (highlight to view): Grandmaster = 5:15, Master = 10:15, Expert = 20:30

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

Note: Follow this link for more Castle Wall puzzles. If you are new to this puzzle type, here are our easiest Castle Wall puzzles to get started on. More Castle Wall puzzles can be found in our beginner-friendly collection Intro to GMPuzzles as well as the larger collection Castle Wall, both by Serkan Yürekli.

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: Slanted Squares

Author/Opus: This is the 2nd puzzle from guest contributor Mark Sweep.

Rules: Standard Castle Wall rules, but none of the clue colors are given. The solver should determine whether each gray clue is white or black. Also, the loop must go straight through the cells with white circles, with a turn in at least one of the cells immediately before/after each white circle. The loop must make a turn in all the black circles, but must go straight in both cells immediately before/after each black circle.

Difficulty: 3.5 stars

Time Standards (highlight to view): Grandmaster = 5:15, Master = 8:00, Expert = 16:00

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

Note: Follow this link for more Castle Wall puzzles. If you are new to this puzzle type, here are our easiest Castle Wall puzzles to get started on. More Castle Wall puzzles can be found in our beginner-friendly collection Intro to GMPuzzles as well as the larger collection Castle Wall, both by Serkan Yürekli.

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: Black Mirror

Author/Opus: This is the 337th puzzle from our managing editor Serkan Yürekli.

Rules: Standard Castle Wall rules.

Difficulty: 3 stars

Time Standards (highlight to view): Grandmaster = 3:30, Master = 4:30, Expert = 9:00

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

Note: Follow this link for more Castle Wall puzzles. If you are new to this puzzle type, here are our easiest Castle Wall puzzles to get started on. More Castle Wall puzzles can be found in our beginner-friendly collection Intro to GMPuzzles as well as the larger collection Castle Wall, both by Serkan Yürekli.

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: Slanted Squares

Author/Opus: This is the 29th puzzle from our contributing puzzlemaster JinHoo Ahn.

Rules: Standard Castle Wall rules.

Difficulty: 2.5 stars

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

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

Note: Follow this link for more Castle Wall puzzles. If you are new to this puzzle type, here are our easiest Castle Wall puzzles to get started on. More Castle Wall puzzles can be found in our beginner-friendly collection Intro to GMPuzzles as well as the larger collection Castle Wall, both by Serkan Yürekli.

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

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: One True King

Author/Opus: This is the 213th puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: Standard Castle Wall rules.

Difficulty: 2 stars

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

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

Note: Follow this link for more Castle Wall puzzles. If you are new to this puzzle type, here are our easiest Castle Wall puzzles to get started on. More Castle Wall puzzles can be found in our beginner-friendly collection Intro to GMPuzzles as well as the larger collection Castle Wall, both by Serkan Yürekli.

In The Art of Sudoku by Thomas Snyder and The Art of Sudoku 2, GMPuzzles has featured masterful collections of classic sudoku and their variations.

We’re kicking off a new series Masterpiece Sudoku Mix where every few months we will release two new collections of ~25 sudoku in a given style. These puzzles will be masterpieces of visual and logical style, written by some of the best puzzle designers in the world. Our first two books feature Even/Odd Sudoku and Thermo-Sudoku, and are available for purchase now on our store. If you purchase both books, you’ll receive a 10% discount at checkout.

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: One Gear

Author/Opus: This is the 204th puzzle from our contributing puzzlemaster Murat Can Tonta.

Rules: Standard Castle Wall rules.

Difficulty: 1 star

Time Standards (highlight to view): Grandmaster = 0:40, Master = 1:00, Expert = 2:00

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

Note: Follow this link for more Castle Wall puzzles. If you are new to this puzzle type, here are our easiest Castle Wall puzzles to get started on. More Castle Wall puzzles can be found in our beginner-friendly collection Intro to GMPuzzles as well as the larger collection Castle Wall, both by Serkan Yürekli.

This year, we have started to have 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 seventh Sunday Stumper is a Japanese Sums (Cipher) puzzle with a hidden theme.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between number entry, sudoku, and shading modes. Note that any extra numbers (in green, blue, or red) or shaded cells outside the grid will interfere with solution checking. So we suggest using the Number mode in black to write notes over the outside clues or in the cipher box below the grid; make sure only blue digits are inside the 11×11 grid and not outside the grid.)

Theme: Hidden

Author/Opus: This is the 203rd puzzle from our contributing puzzlemaster Murat Can Tonta.

Rules: Place the digits 1-9 in some of the cells, so that no digit is repeated in any row or column. Also, all numbers are encrypted with J, A, P, N, E, S, U, M, H, D letters and each letter represents a different digit from 0 to 9. Numbers on the outside of the grid indicate the sums of adjacent digit groups in that row or column, in order. Each sum is separated by at least one unused cell. Single-digit clues cannot be a 0, and also multi-digit clues cannot start with a 0. A question mark indicates a sum value of unknown size, and can be single- or multi-digit.

Or see this (non-cipher) example of Japanese Sums:

Difficulty: 5 stars

Time Standards (highlight to view): Grandmaster = 27:30, Master = 37:00, Expert = 1:14:00

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

Note: Follow this link for other Japanese Sums puzzles.

Our past variety week of Cipher puzzles is collected in this PDF and the solutions are in this PDF.

The daily solution videos are on the posts and linked below:

We’ll be back later today with a Sunday Stumper to close out the Cipher week. We’ll also be posting our next e-books, two Masterpiece Sudoku Mixes focused on Even/Odd Sudoku and Thermo-Sudoku, in the next day.

This next week will feature Castle Wall puzzles.