On this site we showcase “The Art of Puzzles”, with hand-crafted logic puzzles by the best puzzle designers for all who love puzzles. We organize into the categories of Sudoku, Number Placement, Object Placement, Shading, Region Division, and Loop/Path puzzles with tags on each post to find the easiest/hardest within particular styles.

We are currently not posting many new puzzles in 2025 after 12 years of offering so much to the puzzle community. We may have some bonus puzzles from time to time if you keep checking back. There are also many extra puzzles in our subscriptions and books that you may not have seen so check out our Store for more details.

If you are a subscriber for any of our seasons since July 2023, please use this page to login and make sure you see all content.

After twelve years and over three thousand puzzles worth of free entertainment, the GMPuzzles team has made the hard decision to bring the “blog era” of this site to a close. Despite many attempts through the years, we have not been able to make either the community or the business model work in a blog format to unlock the best from our puzzles. There might still be some posts here from time to time with bonus puzzles, and we intend to maintain this website indefinitely given the incredible library of puzzles here. But there should be no expectation of new “daily content” again in the future.

For 2025, GMPuzzles will focus on several of our partner projects bringing daily puzzles to hundreds of thousands of solvers on other platforms. We will also explore alternate ways to package our content for new audiences. In future years, we might find ways to radically redesign this website and launch a new puzzle platform, but our current ambitions are mostly to be the world’s best puzzle designers and to publish through other platforms where they work for our goals.

While our founder, Thomas Snyder, found an unusual way to say goodbye, he hopes the spirit of beautiful puzzles and pushing the limits of sudoku and other puzzle construction continue in those who were drawn to the site. Thomas will be starting a new place for his own blogging, and we the team echo his thoughts that it has been a great 12 years and we’re still excited for the future of Grandmaster Puzzles in whatever shape that takes.

Thanks to all who have been fans, and we hope you run into our puzzles again in the future.

PDF

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

Theme: The Lonely One

Author/Opus: This is the 561st puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Fill each cell with an X or O so that (A) no vertical or horizontal group of three adjacent cells contains the same symbol in all cells (i.e., no XXX or OOO) and (B) each row and column contains an equal number of each symbol. Cells separated by an equals sign (=) must contain the same symbol. Cells separated by a cross (×) must contain different symbols.

Solution: PDF and selected animation.

Note: Follow this link for other Number Placement puzzles.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our The Thirteen Days of Tango Discussion post on the GMPuzzles Discord.

On 25/01/19 at around 5:50 AM, mars opened the second gate and recovered the “coin”, an identification bracelet, left hidden in a tree where olives and oranges cross near a red hovse.

Alongside the “coin” was this hand-written message: “While our diagnoses may be a part of our identities, they cannot be the sole things that define us. I’ve lived too long in fear of mine, when I should still be inspired by what I can do with brilliant minds around me when I try. Knowing that fear is the mind-killer, I leave behind this bracelet of the past, and I go back to pushing the boulder up the hill. You don’t have to imagine me happy. The boulder feels much lighter this time and I know I can get it higher than ever before. See you at the top.”

———-

Congrats to mars for winning the first Grandmaster Puzzle Hunt (see this post for instructions and some trailheads), and gaining responsibility over this blog for at least the next year. Unfortunately there aren’t many “riches” from running GMPuzzles, so if it turns out mars is / are rational actor(s), and not an unduly sentimental patron of puzzles like former management, most projects like subscriptions will be “paused” due to excessive costs. There may still be some puzzles posted here as bonuses, but for now we expect a bit of a gap as mars assesses things. Let’s all celebrate the end of a challenging month of puzzles and other content that will take awhile to fully understand.

PDF

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

Theme: Overlapping Squares

Author/Opus: This is the 560th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Fill each cell with an X or O so that (A) no vertical or horizontal group of three adjacent cells contains the same symbol in all cells (i.e., no XXX or OOO) and (B) each row and column contains an equal number of each symbol. Cells separated by an equals sign (=) must contain the same symbol. Cells separated by a cross (×) must contain different symbols.

Solution: PDF and selected animation.

Note: Follow this link for other Number Placement puzzles.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our The Thirteen Days of Tango Discussion post on the GMPuzzles Discord.

PDF

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

Theme: Frame

Author/Opus: This is the 559th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Fill each cell with an X or O so that (A) no vertical or horizontal group of three adjacent cells contains the same symbol in all cells (i.e., no XXX or OOO) and (B) each row and column contains an equal number of each symbol. Cells separated by an equals sign (=) must contain the same symbol. Cells separated by a cross (×) must contain different symbols.

Solution: PDF and selected animation.

Note: Follow this link for other Number Placement puzzles.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our The Thirteen Days of Tango Discussion post on the GMPuzzles Discord.

Today marks the start of the MIT Mystery Hunt, an event I haven’t played in for five years but that I helped run last year since my team won in 2023. That January 2023, after six months at a job that was not going to work out and where other societal changes had me very hypomanic again, I escaped to Pasadena, California to gather thoughts and maybe play remotely. While walking the streets late at night, sensing the homeless problem and my own poor mental health, I wondered again about a particular set of messages I wrote to my ex-girlfriend in the days, week, and month after my mother’s death from cancer.

Considering my life like a Mystery Hunt puzzle, I wondered if James Joyce the fifteenth and ChatGPT21 came together to try to answer this prompt: “A complicated and solitary man, ‘TS’, trained at {schools} in {subjects} who enjoyed {books/authors}, {movies}, …, struggled with {moral/scientific questions}, has just lost his mother ‘suddenly’ to cancer after about a 15-year battle with the disease. During this time, certain aspects of his relationship to his parents and friends had changed but he hadn’t fully processed them. Present three works TS wrote and sent to ‘his X’, an important relationship from his past, to represent his grieving process. The works are in the style of a lost ‘child’ looking for solace, a scientist trying to analyze the unexplainable, and a friend that has contained (perhaps without processing) the events and returned to an individualistic communication style shared by TS and X. Bonus points for sharing the kind of message X might send to TS to help the transition back to normality.”

Now the prompting needs some work, but maybe there are points when people identify a reference I must know because of a particular sentence or word I use a certain way. Maybe the darker parts aren’t original to me, just subconsciously plagiarized and even that would be interesting as my brain is an aggregator far more than a creator but people ascribe me a huge level of intelligence because I sound like I know what a thousand people think. However it went, I did get checked into a hospital that January over Mystery Hunt weekend as I needed to be sleeping, had not brought the proper medication, and also didn’t understand my condition in anything like the ways I think I do now. There’s a lot more to it than this letter exchange, but so much of my last seven years has been reengaging with the emotions of these three letters and the good and bad they reveal about me. My own struggles and successes have advanced a far bit past this most important event in my life in my last 30s, but there is no doubt this is the most important writing for someone studying my life to consider as I still do.

None of you are probably studying Thomas Snyder in that way, so you should probably not read this deeply sad and possibly profound missive. You could start with tmsnyder FAQ or really just go solve some sudoku. But I need these words to be public and I didn’t start this series without knowing today might be an important conclusion to my oversharing.

The last two “shares” in this series, including today’s, are deeply personal in different ways. And while I didn’t know that I’d get comfortable enough to share all of these, surprisingly it was the “easy” tmsnyder FAQ yesterday that was the most emotional of these pieces for me to revisit this year while preparing for release. This possibly shows how much I miss feeling closer to a real mission in science and working with a team of really great people. Most of the time these days, even when doing my best work, I am incredibly lonely and also feel like I need to tiptoe on eggshells because everyone (ME INCLUDED!) is worried I don’t know how to control my health, watching every sign and signal of my life with a pain and fear I don’t recognize from my loved ones. Even in this corner of puzzles, I didn’t find much of the comfort or joy over Christmas when playfully releasing some sudoku in the world, proving my own test that I may need to be an anonymous designer again if I spend time in puzzles.

But I won’t be an anonymous human being, and will be deliberate in sharing thoughts, writings, and updates at another site to those mature enough to find it and contribute to a dialogue. That site will include some “artifacts” of my life that might be up for revisiting that year, or on permanent exhibition, including all the writings from Ready Layer One and others I’ve shared.

Today I want to share my mask. It was made while in residential care following a third hospitalization (and the second involuntary) in August 2023, and the last time I was not well controlled by medication, therapy, and lifestyle practices depending on how you view this series. The recovery from this episode, still ongoing, was much harder than any of the others, due to the mess of thoughts that came up during it, my lack of confidence in myself following it, large medical bills, legal troubles, and friendships I am scared to even “ping” because of some of the things that might have happened during it. When I had a choice to spend a crazy amount of dollars to go into residential care for a month to start to come to some acceptance with being bipolar, I took it. And acceptance is not just that I am bipolar and have creative bursts and high energy moments, but that it has real real danger with it and however smart someone thinks I am there is no way I can “outthink” my mania or hope to care for this by myself. I need to stay connected and open with doctors, therapists, and loved ones or I cannot be my best self and stay my best self.

Alongside a lot of work during residential care, there was a larger project to make your mask. The prompt was to make a picture of how the world sees you (the outside of the mask), while also capturing how you see yourself (the inside of the mask). My outward look is usually a “mirror” — I try to reflect your thoughts or feelings so except for obvious things I can’t hide like my love of science, puzzles, and games, you don’t get much outwardly most of the time. Even the inside of my mask has a twisted side which is how I think you think I see you. Maybe I am mostly an enigma. Inside my mask on my open side you can see in the emotional mix LOVE is strong but also SAD and LONELY. Around the rim of the mask I wrote an A-Z set of descriptors for me, in the style of some memorable writings from my past and often a changing inventory of adjectives and passions. To help those who want to actually know what those are without working through the video too much:

Amazing, Biotech leader, Compassionate, Diligent, Empathetic, Funny, Grandmaster, Helpful, Integrity, Joyful, Kind, Loving, Marathon runner, No nonsense, Ozymandius-like Observation, Problem solver, Questioning, Radiohead, Sudoku, Team builder, Uncon/venti/onal (written unconventionally), Van Gogh, Worrier, Xoogler, “Yes and,” and Zero to infinity.

The description above scratches the surface of the mask’s meaning, in the same way it scratches the surface of me at this moment in my life. But I am open to anyone who wants to see more.

Video of the artwork

I have a lot more therapy art, but nothing else that I am sharing this year or that is more directly “me”. I look at this many nights on my bed stand to understand which of the alphabet of problems and possibilities is the one for today.

PDF

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

Theme: Wedges

Author/Opus: This is the 558th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Fill each cell with an X or O so that (A) no vertical or horizontal group of three adjacent cells contains the same symbol in all cells (i.e., no XXX or OOO) and (B) each row and column contains an equal number of each symbol. Cells separated by an equals sign (=) must contain the same symbol. Cells separated by a cross (×) must contain different symbols.

Solution: PDF and selected animation.

Note: Follow this link for other Number Placement puzzles.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our The Thirteen Days of Tango Discussion post on the GMPuzzles Discord.

I wanted* to share some more foundational documents, that are not at all for solving my puzzles but are about understanding me as a person as I turned/turn/will turn 45. This is “tmsnyder FAQ“, a document I wrote for the most incredible team of computational biologists and software engineers (and other collaborating team members) to know better how to interact with me. Within its structure are certain lessons like all of our superpowers and also our main weaknesses (and vice versa). Please read and comment if you are interested in knowing me better. My former team members still ask to see this every once in awhile so figured the world should have it.

—

*in the world of Ready Layer One, the leading player mars, either an AI, a team of testsolvers I pay to be ahead of everyone else, or who knows since there aren’t a flock of players building out the mythology so we don’t need an IOI, has traded in some of their earned items for extra info on harder content than anyone else has seen. Other foundational documents are expected to be released as they have actually traded everything in their search for the second door, having found the second keyword last night in the form of a time-traveling fox. So the leaderboard has some big changes coming soon, if it even exists.

Since there is no puzzle here for most solvers, I’ll share the easter egg directly of a photo from when I was 37 and our Parkinson’s team got to meet a special funder of neurodegenerative research (cropped from a larger group photo).