Announcing: The Twelve Days of Sudoku

Twelve Days of Sudoku by Thomas Snyder

Early reviews that chatGPT was probably prompted enough times to finally hallucinate include:

  • “The best thing Snyder’s done to improve understanding of logic puzzle construction since Puzzlecraft
  • “Mostly clueless, certainly too focused on the number forty-five which isn’t the answer to anything, but fun nonetheless”.

Join the discussion on the GMPuzzles Discord.

Note: The puzzle in the image above, a perfect combination of ideas we’ve explored in 2024 (one-star Queens/Star Battle and creative Sudoku), is a Christmas favorite from 2018.

——–
Added (2:05PM) Several people have asked what kind of sudoku might appear, people who are interested in puzzles and wanted to check in on me as we tend to do at the end of the year (I turn 45 in January and have had a good year, thanks for asking!).

Well, the main series is going to be Classic Sudoku as you know it. Because it is interesting to me for a lot of reasons including testing approaches to competition and puzzle setting / design rules and searching for unexpected things where people have stopped looking.

But I have been thinking of other interesting ideas to share for those who aren’t into classic sudoku puzzles but like other puzzles and things. Ideas that might pop up when I’m also thinking about the silly “is AI coming to take my job” question as I got in a recent interview on LinkedIn. As a creative thinker and problem solver, I can do more with a broken pencil than an AI in puzzle design even if I prefer to work digitally and with software tools and even AI sometimes.

Today, I challenged myself to write the most interesting sudoku I could with just one missing digit. It is a fun prompt to give a puzzle constructor and/or AI because it might not make sense. The image below isn’t my answer. But it is a start.

Twelve Days of Sudoku by Thomas Snyder

I didn’t go smaller, as it turns out I can’t outdo Randall’s Binary Sudoku but that doesn’t have proper regions anyway so I argue this is the absolute smallest for a 1-cell blank puzzle.

And in terms of what is coming, I have written the most interesting 80-given Sudoku-ey thing in history with one missing cell I’d love to see how you’d fill. But it’s not ready to share yet. It is the Ulysses of 1-cell missing Sudoku and before today you didn’t even think about those.

Bonus: Star Battle (also known as Queens) by Thomas Snyder

Earlier this year, Thomas helped provide puzzles for the launch of the LinkedIn game Queens, a very accessible, one-star version of Star Battle puzzles. We have posted some weekly Queens bonuses here through this season, including this puzzle in the form of a hashtag.

Star Battle by Thomas Snyder

PDF

or solve online (using our beta test of Penpa-Edit tools; in composite Star Battle mode a left click places a star, right click in a cell marks off the cell, and a right click on an edge or corner marks in a dot as a placement note.)

Theme: Hashtag

Author/Opus: This is the 534th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Star Battle rules. One star per row, column, and region.

Difficulty: 2 stars

Time Standards (highlight to view): Grandmaster = 1:00, Master = 1:30, Expert = 3:00

Solution: PDF and solving animation.

Note: Follow this link for other one-star Star Battle puzzles exactly like Queens, and this link for our easiest Star Battles, including many with two stars per region, which are a great way to get started on this version of the puzzle. More Star Battle puzzles can be found in these books in our e-store including our Starter Pack 5: Star Battle book.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Week 12 Discussion post on the GMPuzzles Discord.

Bonus: Star Battle (also known as Queens) by Thomas Snyder

Earlier this year, Thomas helped provide puzzles for the launch of the LinkedIn game Queens, a very accessible, one-star version of Star Battle puzzles. We will be posting some weekly Queens bonuses here through this season, including this challenging puzzle formed out of two heart shapes.

Star Battle by Thomas Snyder

PDF

or solve online (using our beta test of Penpa-Edit tools; in composite Star Battle mode a left click places a star, right click in a cell marks off the cell, and a right click on an edge or corner marks in a dot as a placement note.)

Theme: Two Hearts

Author/Opus: This is the 531st puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Star Battle rules. One star per row, column, and region.

Difficulty: 3 stars

Time Standards (highlight to view): Grandmaster = 1:45, Master = 4:00, Expert = 8:00

Solution: PDF and solving animation.

Note: Follow this link for other one-star Star Battle puzzles exactly like Queens, and this link for our easiest Star Battles, including many with two stars per region, which are a great way to get started on this version of the puzzle. More Star Battle puzzles can be found in these books in our e-store including our Starter Pack 5: Star Battle book.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Week 11 Discussion post on the GMPuzzles Discord.

Bonus: Star Battle (also known as Queens) by Thomas Snyder

Earlier this year, Thomas helped provide puzzles for the launch of the LinkedIn game Queens, a very accessible, one-star version of Star Battle puzzles. We will be posting some weekly Queens bonuses here through this season, including this puzzle with a set of stacks in the center.

Star Battle by Thomas Snyder

PDF

or solve online (using our beta test of Penpa-Edit tools; in composite Star Battle mode a left click places a star, right click in a cell marks off the cell, and a right click on an edge or corner marks in a dot as a placement note.)

Theme: Stack

Author/Opus: This is the 528th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Star Battle rules. One star per row, column, and region.

Difficulty: 1.5 stars

Time Standards (highlight to view): Grandmaster = 0:45, Master = 1:15, Expert = 2:30

Solution: PDF and solving animation.

Note: Follow this link for other one-star Star Battle puzzles exactly like Queens, and this link for our easiest Star Battles, including many with two stars per region, which are a great way to get started on this version of the puzzle. More Star Battle puzzles can be found in these books in our e-store including our Starter Pack 5: Star Battle book.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Week 10 Discussion post on the GMPuzzles Discord.

Consecutive Pairs Sudoku by Thomas Snyder

This is a free “warm-up” puzzle; Season 4 subscribers will see today’s main puzzle in the same style posted at 9:05 AM PT.

Consectuive Pairs Sudoku by Thomas Snyder

PDF

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

Theme: Checkered

Author/Opus: This is the 526th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Consecutive Pairs Sudoku rules. (If a gray circle is given between two adjacent cells, then the two numbers in those cells must be consecutive. Note not all gray circles are given; adjacent cells without a circle may contain either consecutive numbers or nonconsecutive numbers.)

Difficulty: 1 star

Time Standards (highlight to view): Grandmaster = 0:30, Master = 0:45, Expert = 1:30

Solution: PDF and solving animation.

Note: Follow this link for Consecutive Pairs Sudoku puzzles on this website. If you are new to this puzzle type, here are our easiest Consecutive Pairs Sudoku to get started on. More Consecutive Pairs Sudoku puzzles can be found in these books in our e-store.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Week 10 Discussion post on the GMPuzzles Discord.

Bonus: Star Battle (also known as Queens) by Thomas Snyder

Earlier this year, Thomas helped provide puzzles for the launch of the LinkedIn game Queens, a very accessible, one-star version of Star Battle puzzles. We will be posting some weekly Queens bonuses here through this season, including this large puzzle that might be as “easy” as ABC?

Star Battle by Thomas Snyder

PDF

or solve online (using our beta test of Penpa-Edit tools; in composite Star Battle mode a left click places a star, right click in a cell marks off the cell, and a right click on an edge or corner marks in a dot as a placement note.)

Theme: ABC

Author/Opus: This is the 523rd puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Star Battle rules. One star per row, column, and region.

Difficulty: 2 stars

Time Standards (highlight to view): Grandmaster = 1:15, Master = 2:30, Expert = 5:00

Solution: PDF and solving animation.

Note: Follow this link for other one-star Star Battle puzzles exactly like Queens, and this link for our easiest Star Battles, including many with two stars per region, which are a great way to get started on this version of the puzzle. More Star Battle puzzles can be found in these books in our e-store including our Starter Pack 5: Star Battle book.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Week 9 Discussion post on the GMPuzzles Discord.

Tapa by Thomas Snyder

This is a free “warm-up” puzzle; Season 4 subscribers will see today’s main puzzle in the same style posted at 9:05 AM PT.

Tapa by Thomas Snyder

PDF

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

Theme: Knight’s Moves Revisited

Author/Opus: This is the 522nd puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Tapa rules.

Difficulty: 1 star

Time Standards (highlight to view): Grandmaster = 0:30, Master = 0:45, Expert = 1:30

Solution: PDF and solving animation.

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

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Week 9 Discussion post on the GMPuzzles Discord.

Tapa by Thomas Snyder

This is a free “warm-up” puzzle; Season 4 subscribers will see today’s main puzzle in the same style posted at 9:05 AM PT.

Tapa by Thomas Snyder

PDF

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

Theme: Knight’s Moves

Author/Opus: This is the 521st puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Tapa rules.

Difficulty: 1 star

Time Standards (highlight to view): Grandmaster = 0:25, Master = 0:35, Expert = 1:10

Solution: PDF and solving animation.

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

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Week 9 Discussion post on the GMPuzzles Discord.

Bonus: Star Battle (also known as Queens) by Thomas Snyder

Earlier this year, Thomas helped provide puzzles for the launch of the LinkedIn game Queens, a very accessible, one-star version of Star Battle puzzles. We will be posting some weekly Queens bonuses here through this season, including this surprisingly tough puzzle, despite its cheerful appearance.

Star Battle by Thomas Snyder

PDF

or solve online (using our beta test of Penpa-Edit tools; in composite Star Battle mode a left click places a star, right click in a cell marks off the cell, and a right click on an edge or corner marks in a dot as a placement note.)

Theme: Smiley Face

Author/Opus: This is the 520th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Star Battle rules. One star per row, column, and region.

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 1:15, Master = 2:30, Expert = 5:00

Solution: PDF and solving animation.

Note: Follow this link for other one-star Star Battle puzzles exactly like Queens, and this link for our easiest Star Battles, including many with two stars per region, which are a great way to get started on this version of the puzzle. More Star Battle puzzles can be found in these books in our e-store including our Starter Pack 5: Star Battle book.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Week 8 Discussion post on the GMPuzzles Discord.

Cave (Hex) by Thomas Snyder

This is a free “warm-up” puzzle; Season 4 subscribers will see today’s main puzzle in the same style posted at 9:05 AM PT.

Cave (Hex) by Thomas Snyder

PDF

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

Theme: Hex Pairs

Author/Opus: This is the 518th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Cave rules. (The puzzle is on a hexagonal grid and cells now see in a maximum of six possible directions.)

Difficulty: 2 stars

Time Standards (highlight to view): Grandmaster = 1:15, Master = 2:30, Expert = 5:00

Solution: PDF and solving animation.

Note: Follow this link for classic Caves and this link for Cave variations. If you are new to this puzzle type, here are our easiest Cave Puzzles to get started on. More Cave puzzles can be found in these books in our e-store.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Week 8 Discussion post on the GMPuzzles Discord.