Community Building

This is a bit of a ‘random thoughts’ kinda post. But before I go on, I want to share that my parents got me this T-shirt and I love it:

Anyway, the main reason for this post is, I’ve been thinking about the difference between casual puzzle solving and competitive puzzle solving. Soon I’ll be starting the 2023 editions of Sudoku Mahabharat and Puzzle Ramayan, and the WPF will start the 2023 editions of the Sudoku GP and Puzzle GP. There are competitions galore online and maybe some offline too as we start another season leading up to the World Championships. *Edit*: I shouldn’t mention all this without mentioning the lovely beginner-friendly contest this weekend on LMI, PANFOPCWHTTAPA 3. The first two editions were great for newer solvers looking to learn new puzzle genres and get into competitive solving for the first time. Check it out!

This process, largely, ignoring small mishaps and challenges here and there, has been carried out quite smoothly in recent years (in another discussion it may be worth actually appreciating what we are able to do as a community year on year with little to no monetary benefit and a heavy lack of personnel in some cases) and I have confidence that that will continue.

However, this post is for discussing other things we can do, to keep the casual puzzlers component of the community involved through the year to a similar extent. I’m very interested in exploring this side of things more. Over recent years I have been trying to capture people in different ways. One big way is trying to expand our author pool for SM and PR and give new and young authors a chance and platform. Puzzle construction doesn’t involve the same pressures of competitive solving and is probably more accessible in that sense for those who are interested in the hobby to keep in touch with it meaningfully.

Another way is to hold more casual mini-events as part of our National Championships. During the offline Indian Sudoku Championship there was a simple team round I ran after the main competition while the organizers were checking, where groups of 3 got together to figure out the connection between some Sudokus and try to solve them together. Similarly, during the offline Indian puzzle Championship, I simply put together groups led by some prominent authors of our community, to teach people the processes involved in writing puzzles. The aim of these side events (other than giving the checkers time to put out the results) is to introduce a social component within the experience.

The last way, which I don’t see enough of (I may just be missing it) across the community and probably want to focus on more here, is to hold meetups regularly. Since India is a large country, we mostly plan meetups specifically for Mumbai, the city I live in. The first meetup I had in Mumbai, was basically just a two-person hangout where I helped another solver get through some tough Sudokus. This was many years ago, and since then, with that other solver’s help and others along the way, we built a regular functioning group with monthly meetups in the area.

After the obvious gap caused by Covid-19, we are now rebuilding this meetup culture. We have a stable venue and a consistent agenda comprising of:
1. Casually start solving some (hopefully) approachable Sudokus that vaguely escalate in difficulty while I float around helping where needed, but also get aided by the stronger solvers who attend these.

2. Introducing and teaching a new non-Sudoku puzzle type.

3. Having a team-solving round from some past competition, trying to group more established solvers with newer/casual ones.

The feedback I’ve got from the participants is overwhelmingly positive, and over the years its given some casual solvers a good way to stay connected. It also gives some of them more encouragement to participate in competitions, knowing that the social component carries forward even if they’re not necessarily contenders for the top positions.

The other, more unexpected positive I’ve seen is the variance in demographic. While most of India’s (and the world’s) top solvers are males around 25-35 years of age, the Sudoku meets I conduct have many regular female participants. I can’t help but feel there’s something there, for whatever reasons, with casual solving being more appealing to female puzzlers than competitive solving. I remember conducting a meet pre-covid where there were 22 participants and 20 were female! The demographic has leveled out more post covid, but it is still usually a good ratio.

These meets are pretty easy to conduct. Find a local cafe that allows for group meetups, use some selection of puzzles from an old LMI set or GP set or WSC/WPC set and just get together and interact while solving. It probably helps to have some solvers around who are more established and can help, but it is quite doable without that too.

I’d like to see more offline meetups in different places. I think it definitely benefits the community in ways that competitions do not and goes hand in hand nicely with the competitive part.

I’d also love to see other suggestions to tap into casual puzzle solving audiences and keep them engaged. There have been some good attempts, with Tawan’s quizzes and contests, the Puzzle GP’s experiment with a casual section, etc. which are good ideas to build on too.

I’ll end this post with photos from our most recent meet, where they surprised me with a cake and a small celebration at the end of the meet to commemorate my WPC performance. It was a fulfilling and heartwarming end to the meet and shows that we are building a pretty cool community with these meets.


Puzzle No. 521: Cross The Streams

Edit: I posted the wrong version. Apologies. Corrected now.

Yay, a big puzzle!

Rules: Shade some empty cells black to create a single group of black cells that are all connected to each other through their edges. No 2×2 cell area within the grid contains all black cells. Numbers to the left/top of the grid represent the groups of consecutive black cells which are in that row/column in order, either from left to right or from top to bottom. For example, a clue of “3” means the row or column has three consecutive black cells, and a clue of “3 1” means that the row or column has a group of three consecutive black cells followed by a single black cell, separated by at least one white cell. A question mark (?) represents a group of consecutive black cells whose size is unknown; an asterisk (*) represents any number of unknown groups of black cells, including none at all.


Penpa link:


Puzzle No. 520: Country Road

I have a lot of pending things to get to, which I hopefully do by the end of the month, including some more elaborate blog posts.

For now though, this is a puzzle.


Draw a non-intersecting loop through the centers of some cells which passes through each region exactly once. A number in a region represents how many cells in the region are visited by the loop. Orthogonally adjacent cells across a region border may not both be unused. The black cell just means it’s a hollow, I.e., not part of the grid.


Puzzle No. 517-519: Nikoli! (Tribute to Maki Kaji)

I haven’t posted in a while. There are a bunch of reasons for this, including travel and a bad reaction to my first vaccine dose.

Anyway, today’s post is a tribute to Maki Kaji, who passed away last week from cancer. I was going to elaborate on my thoughts more, but honestly this post by Thomas pretty much says exactly what I wanted to, perhaps in a better way.

I got into pretty late, and just had a year of solving before the online solving portion had to close. I do purchase their books from time to time and I absolutely love the giants series.

Like Thomas, my note of thanks will be for his broader contribution to the puzzle community via Nikoli, influencing me and so many other puzzlers positively.

As a tribute, I have written 3 Nikoli style puzzles, and by that I mean ‘Nikoli style’ – I’ve tried to keep look, difficulty and dimensions as I remember them from



  1. Place light bulbs (circles) according to the following rules.
  2. Light bulbs may be placed in any of the white squares, the number in the square shows how many light bulbs are next to it, vertically and horizontally.
  3. Each light bulb illuminates from bulb to black square or outer frame in its row and column.
  4. Every white square must be illuminated and a light bulb can not illuminate another light bulb.


  1. Place black “triangles in squares” (see 2) in the grid under the following rules.
  2. There are four kinds of black triangles you can put in the squares (shown below)
    . You cannot place black triangles in the black squares.
  3. The parts of the grid that remain white (uncovered by black triangles) always form a rectangle or a square.
  4. The numbers indicate how many black triangles are around it, vertically and horizontally.


  1. A rectangle, bordered by bold lines, is called a “room”. Fill in cells under the following rules.
  2. The numbers indicate how many painted cells there are in a room. Rooms with no number may have any number of painted cells.
  3. White cells cannot stretch across more than two rooms in a straight line.
  4. Painted cells cannot be connected horizontally or vertically. White cells must not be separated by painted cells.

Rule credits:

Penpa links




Puzzle No. 514-516: Tapa, Tapa [Palindrome], Tapa

I got a bit late when it comes to keeping my alternate day schedule so here are 3 puzzles to make up for it.

Only the last one is “fresh”. The first one is a bit silly but also probably nice, I was experimenting with an idea, some people on discord have seen it already. The second one, the variant, is from a speedsetting contest quite a while ago. We had an hour to construct a Palindrome variant. This one took me about 35 minutes if I recall correctly. The third one is just a vanilla Tapa.

Tapa Rules: Shade some empty cells to create a single connected wall. Numbers in a cell indicate the length of consecutive shaded blocks in the neighboring cells. If there is more than one number in a cell, then there must be at least one unshaded cell between the shaded cell groups. Cells with numbers cannot be shaded, and the shaded cells cannot form a 2×2 square anywhere in the grid.

Palindrome variant additional rules: There are one or more palindrome lines drawn in the grid. The pattern of shaded and unshaded squares will be the same when read from either end of a line.

Links to solve each one:

Puzzle 514

Puzzle 515

Puzzle 516

Puzzle 514:

Puzzle 515:

Puzzle 516:

Puzzle No. 513: Shakashaka

Lets start with an unrelated self-plug – Check this out!

Now to today’s puzzle. This is a “fresh” puzzle, i.e. only 2 or 3 people have seen it before.

Rules – Shade a right triangle in some empty cells, each of which occupies exactly half the cell it’s in. Each unshaded area must be rectangular in shape. A number in a cell represents how many of the (up to) four cells orthogonally adjacent to the clue contain triangles.

Penpa link to solve: (Click+drag slightly to a corner to draw in that corner’s triangle, just click for dot)

Puzzle No. 512: Kurotto

Since I’ve just been back here recently, I should note that sometimes, I won’t be posting “fresh” puzzles. Mostly this is because I also want to use the blog to organize some of these puzzles better.

I have been participating in “speedsetting” contests lately over on the CTC discord server. I’ve seen that this may seem unappealing to some more experienced puzzlemakers, but honestly, its a lot of fun. Also, mostly it allows me to put together something without overthinking about “where will it get published” and “what are the requirements”, while being in a limited time setting that makes me “feel” like I am doing something different.

What about the quality of the puzzle then? I’ll let you be the judge, with today’s puzzle, which is from a speedsetting event that took place just 6 or 7 hours ago. The constraints given were to construct a Kurotto with the only clues being in sets of 3 orthogonally connected cells, of the same shape (allowing for rotations and reflections). Basically, either a puzzle with only L trimino sets of clues or a puzzle with only I trimino sets of clues. The time given was 40 minutes but I forgot about it and joined late. Fortunately, its Kurotto, probably as comfortable for me as Tapa, so I could whip this up in 5-6 minutes. It won 2nd place!

I have more puzzles from earlier speedsetting contests that I’ll be posting in the future, but for now, here is the Kurotto!

Rules: Shade some cells so that each circled number represents the total count of shaded cells in connected groups sharing an edge with that number. Cells with circles cannot be shaded.

Link to solve on Penpa:

Puzzle No. 510: Akari

So… I’m back.

I wondered what I could possibly say along with starting to post here after such a long hiatus (from here anyway).

I do plan to start posting here regularly again though. Why? I guess we may or may not find out.

So after a lot of thought on what to post as my return puzzle, I decided, I just want to keep things simple.

So here’s a vanilla Akari.


Place lights in some cells so that every cell is illuminated. Lights illuminate the cell they’re in as well as all cells seen in a straight line horizontally or vertically, not obstructed by a black cell. Lights may not illuminate each other. Clues represent the number of lights in the (up to) four cells surrounding the clue.

We have penpa links now! Why penpa over some other platforms for this blog? I’ll probably write about that in a future post. I’ll also write about someone doing some nice work to make links out of some of the older puzzles of this blog. All that and more to come. For now, link to solve:

The link is set to composite mode specialized towards solving Akari, and drawing in the bulbs correctly will trigger the answer check.

Puzzle No. 500 – 9 Shady Masterminds [Special] [Marathon]

I thought quite a bit about what I wanted for my 500th puzzle here. There was a stage when I thought I’d just ignore the milestone and post something normal. Then I got a bit of an idea of a simple theme which might still give out a nice solve path with different logical deductions combining.

The puzzle that resulted from this idea is pretty narrow and quite difficult, according to my and Swaroop‘s test solving experiences. Still, I think its ended up being quite varied in the thinking required and I like how it turned out.

Unlike my usual approach of posting a single image, for this puzzle I am attaching a PDF instead. This PDF has 4 pages. The first page contains the puzzle. The 2nd and 3rd pages contain the rules (The length is just because there are 9 different puzzles to cover, but most of them are familiar and should just be a quick read-through). There are two newer puzzle types, and one variant which I couldn’t immediately find an example for, so I have added 6×6 examples for these three rule-sets. The remaining are all classics, so I’ve just linked to the respective page where I got the rules from, and you can visit these links if you want an example. If you are new here and haven’t seen those sites before, I suggest visiting them anyway for more great puzzles.

Here’s the PDF:

9 Shady Masterminds

Please let me know in the comments or by mail ( if you have any queries regarding the rules or any other issues.

Announcing: LMI Sudoku Mahabharat

This August, the Indian team was in London for the World Sudoku and Puzzle Championships. I have been recapping my personal experiences there, and I will continue to do so, with two parts left in the series. However, it is now time to draw attention to one of the ideas that came up during our discussions in London.

A little background first. In 2012, the Indian Sudoku team was decided by the Times Sudoku Championship (A National-level event conducted by Logic Masters India and The Times of India) for the first time (Previously, it was decided by the Indian Sudoku Championship, organized solely by LMI).  Though I would definitely do things differently on the publicity side, and I think it could’ve been a whole lot better, the partnership did cause a substantial increase in participation, going from hundreds to thousands.

The problem is, there aren’t that many new regular Sudoku enthusiasts coming out of it. Especially now Rohan Rao, Rishi Puri and myself seem to be, without doubt, the best three players in India, switching orders in different competitions over the last two years. Sumit Bothra, Jaipal Reddy, Gaurav Korde, Rakesh Rai, Ritesh Gupta etc. are all great Sudoku solvers who are regularly in the top 10, but there aren’t many new faces.

There are many opinions on why this is the case, but for the purpose of this blog post, I’ll put my own out there: It is quite simply because, at the stage where there is highest participation, there isn’t any exposure to the level at which the Sudoku regulars practice. By the time the National Finals with higher variety and difficulty takes place, only the old guard make it. However, this isn’t a problem with an easy solution – you cannot make the earlier round hard as that would demoralize newcomers pretty quickly, and you want a fun event first and foremost. The only solution seems to be to increase the numbers that make the finals, and since it is the sponsors who will need to make added expenditure to transport the finalists, the final decision in this case has to be theirs.

Either way, for any enthusiast thinking it is too difficult to step up into the top Indian ranks, well obviously it isn’t (and shouldn’t be) easy, but it is very much possible to make a quick ascent. Just look at the most recent climbers – myself around 2012, and Kishore Kumar now. The path for both of us has been similar in the sense that we both were regular in online competitions which mimicked the standards of the World Championships. We may have been bad at the new variants at the start, but that’s definitely the level to practice at, and will mostly help to break into the top ranks.


This is where Sudoku Mahabharat comes in (quick clarification – depending on the success of this event, we DO hope to have a Puzzle Mahabharat as well in future years). Is this the only plan to give an opportunity to new talent? No, and there will be other projects announced. But the novelty of this tournament does address some issues. First and foremost, this tournament is organized by some of the regulars of the Indian teams that have been going to the World Championships in recent years. This means most of the top solvers are not competing. The aims of the competition, in relevance to the issues above, are as follows:

1. A competitive format is offered here, and the importance of this can never be understated. Solving a single Classic on a publication or website is different from solving a group of them in a timed format. There is a challenge in both areas, but the National and World Championships are built on a competitive multi-Sudoku timed-round environment. In such an environment, there is room to improve even in Classics for a Sudoku enthusiast.

2. This tournament will provide a look into the variations that appear at higher levels, in a categorized format to help in understanding them. It will also provide both an easy sample of the variant and a more difficult, regular sized version of the variant. The newcomers will have a chance to try out new variants in the easier format, and later move on to the harder levels of the same variants. This structure ensures that every participant has a fun challenge to look forward to.

3. To give new talent the chance to shine in a National level competition. There is hope that this will further encourage the winner to participate more regularly.

So here’s an invite to all Indian Sudoku enthusiasts to a great opportunity. Please visit the following pages to know more about the event, which will also feature an offline final in 2015.

The main Sudoku Mahabharat page:

The Sudoku Mahabharat Discussion thread:

The first round, with Standard Variations, by Rishi Puri, which starts on the 20th of September:

Also, if you want to support LMI in its various projects, please consider being a patron to the group. To know more, please visit this page: