Logic Masters Deutschland e.V.

It's now almost two years when Aaronomys, Piatato and me made the toddler pack. In that one my younger son appeared as a spiritual guide through the puzzles. Since that time I knew a owe a proper thug life picture to my older son too. Now I'm finally paying off that debt.

A lot of people, or their puzzles, inspired me while working on the pack - that includes at minimum berni, Kafkapharnaum, MagnusJosefsson, Piatato, PrimeWeasel and wisty - thank you!

Finally, enormous thanks to dumediat, MicroStudy, Piatato, The Book Wyrm, wisty and zzw for testing either the individual puzzles, or the whole pack.

You can also download the pack as a PDF file. (Note that the puzzle titles are also penpa+ links.)

Enjoy!

The Professor

Part I. - The Troubled Kid

I shouldn't have done it, but I have, everybody told me not to, my shoes told me not to, but I have and there's no point for a well meaning advice now, yeah, I absolutely shouldn't have, but I have.

What happened is, I got a bit nervous since I haven't made a puzzle for a while, I got so desperate I have done what I shouldn't have - I opened the folder where I store all my absolutely failed, cursed and broken ideas - and did I say enough times, I shouldn't have done it?

Of course, it's not an actual folder, I am not organized enough to put anything into a folder of any kind. It's just in my head. It's also in my browser, though. And as I was going through those endless tabs, looking at those broken grids, puzzles with 51.79 solutions and rulesets that you need to scroll down for half and hour in order to get to the rule 2 out of 13572. And not all of them are really that bad, some might be sort of cute and perhaps even solvable example puzzles - just the main puzzle somehow didn't get to exist, so you just learn the ruleset for nothing.

So going through those puzzles ranging from horrible to terrible I got an idea. You know like from time to time you just have to take all those ingredients you store in the kitchen even though you should have thrown them away months ago. And rather then actually throwing them in a bin you put them in a blender and gently mix them just enough so you can spread them on a pizza dough. And on the top of that you add some cheese you found in the back of your fridge, cheese that smells way too funny even for a cheese, but still somehow holds it together. Yum.

So what I thought was, what if I simply put them in a pack - a pack of failed ideas - where each individual failed puzzle would somehow start to make sense.

Naturally, what I should have done at that point next was to put that idea into that folder too, close it and forget, as I was once again absolutely clueless how to even start doing that.

No point to describe those sleepless nights and painful days that followed after I opened that Pandora's box. All looked grim, but then I met that kid. A true puzzler for life. And everything changed.

The other kids called him the Professor and I was already pretty puzzled by that, since he apparently didn't even go to school at all. I guess, every kid with glasses that has a proper nerdy hobby like puzzling gets called professor nowadays. I don't know.

And what a curious persona he was. Half of the time we had so much laugh together, but sometimes I was not even sure he noticed I was in the same room. Half of the time he spoke normally, but then something changes and it felt he was using some kind of cipher or a different language or something. Very strange. I am not sure what to say so you can get to know him better, which surely might be of use for you, as you might expect, I don't know if I know him that well myself.

One thing I know, though. He shattered the narrow way I see puzzles completely and in a way he also changed the course of my life.

This surely is the oldest puzzle on the list and also the first puzzle I showed him. Something I made so long ago at the time when I thought I can make a decent region building without getting too mad.

This was an easy puzzle to choose for the start, simple rules, small grid, even the clues seem somewhat meaningful - easy to deceive anyone about what's coming next.

As usual with chaos constructions, you fill in the grid with digits 1 to 4 without repeats in any column or row. You also draw four regions of size four again without repeating digits.

Now the supposed clever twist is that not all regions are necessarily orthogonally connected, some of them can be diagonally connected (i.e. any two cells in that region can be connected by a diagonal path within that region).

The red lines are region sum lines - for each line, digits on the line have an equal sum within each region the line passes through. Every line must enter at least two regions.

The Professor solved the puzzle and just looked at me in perhaps the most uninterested way possible. But at the same time it was clear he's asking for more.

In any case, I took that as a win - he got hooked.

After a start like that, I wanted to continue with something evil. And surely there's many options to miss in this one, and rules to forget, but in the end such fake trickiness alone just can't make a proper evil I guess.

So in this puzzle you make a loop that can cross itself, but otherwise visits every cell at most once and moves only orthogonally.

Also the loop has two types of segments red and blue, but can change color only when it turns. Each single colored segment of the loop has as many turns as it has intersections.

Red cells must contain red segments and can't contain blue segments, blue cells must contain blue segments and can't contain red segments, purple cells must contain both red and blue segments.

Now after the Professor solved that puzzle we got into a crazy long debate over solution codes. In his view all solution codes should contain digits only. For instance letters - he argued - there is just nothing cool you can do with letters (he probably never read a book). But with digits and numbers - he continued - for start you can add them, subtract, multiply or divide them, you can make powers and roots, if you want you can treat the whole solution code as one number. You can even order codes for the lines and the columns and finally make a proper solution codes ranking you always wanted - crazy stuff.

Of course, no outside clues count, only the main grid (of course).

For instance for the Two Color Loop puzzle he suggested: empty cell=1, blue straight segment=2, red straight segment=3, blue corner=4, red corner=5, red and blue corner=6, crossing=7. Wow.

By the way, for the first puzzle he suggested just writing digits normally and only insert 0, when there is a region border between two regions.

Another puzzle, another wasted opportunity. Naturally, If I was clever enough, I could have turned this concept into a full blown in your face allegory of modern urbanism, but in the end, I was just happy the puzzle looks a bit like a skyscraper. And even that is just because I set it on my phone.

Each row, column and blue line contains digits 1 to 6 once each. The outside clues (in the dotted area) are standard skyscraper clues, but the clues further from the grid take into account all digits between its cell and the grid as well as the digits in the grid.

What are the skyscraper clues? Imagine the digits as skyscrapers with corresponding height, then the clue tells you how many skyscrapers one can see in the corresponding direction. Each skyscraper blocks the view of the ones of the same size or lower.

The Professor solved it and, finally, was happy with just simple digits for the solution code.

Likewise, this one could lay on a junkyard nearby any modern art gallery in the world with the name The True Face Of Industrial Revolution on it, but I just went with Kropki Loops, as it was inspired by black and white kropki ruleset.

It is basically like the previous crossing loop puzzle, except now you have two loops, which naturally should be a black loop and a white loop. But as white is a bit impractical, I won't blame you, if you choose another color.

Unlike the previous puzzle everything is given here, perhaps except for the loops, the black cells are exactly the cells not visited by any loop (not even the black one), and the gray cells are exactly those cells where the black and white loops cross. Every other cell is visited exactly one time by exactly one loop.

Now, for the white loop, the lengths of the segments from a crossing until the first turn on either side are consecutive, for the black loop, the lengths of the segments from a crossing until the first turn on either side are of ratio 1:2.

After solving it, the Professor suggested the solution code encoding: empty cell=1, black straight segment=2, white straight segment=3, black corner=4, white corner=5, crossing=6.

Yeah, people make ciphered puzzles all the time, but it seems to me the main reason ciphers are so popular is that the ciphered digits allow you to include the so called funny messages within the clues - and completely overwhelmed by that people totally ignore the letters inherit a cool structure from, well, from the alphabet.

However, the endless potential of combining that idea with all sorts of constraints only ended up as a lazy 5x5 skyscraper puzzle with few mostly 2-cell thermos needed to disambiguate the quality of the puzzle as something way outside the realm of acceptable.

In order to solve this one you need to place the digits 1 to 5 without repeats in every row and column and break a devious cipher as each letter A to E corresponds to a unique digit 1 to 5.

The outside clues are like the normal skyscraper clues from earlier, however, the heights of the skyscrapers can be ordered either numerically (1 lowest/5 highest) or alphabetically (A lowest/E highest). The choice of the ordering must be deduced for each clue.

To be sure you don't heat up too much, there are some thermometers to help. Digits along these thermometers strictly increase with respect to at least one ordering - numerical/alphabetical. Again, the choice of the ordering must be deduced for each thermometer.

The Professor solved it with a smile on his face and decided that the solution code will be just digits, nothing fancy this time.

Believe me, this puzzle wasn't supposed to be that big, but once I unleashed it, I just couldn't contain it and the grid simply exploded. What you are supposed to do here is to draw an U-Bahn network and a slitherlink loop.

For the U-Bahn you just draw some lines connecting centers of orthogonally adjacent cells such that the network they create is connected and has no dead ends. You also write digits 0 to 3 in each cell with the network, the other cells remain empty. The digits correspond to the network shape in their cell as follows: 0=L, 1=I, 2=T, 3=X. Some digits are given, those must also contain the corresponding U-Bahn piece.

You also draw a slitherlink loop - a non intersecting loop along the edges. Digits you obtained from the U-Bahn indicate how many neighboured edges are used by the loop.

As the Professor was solving it, he looked more and more concerned, but having no preconceptions at his young age he went on finishing the puzzle anyway. In the end, though, he almost fell from his chair.

After recovering from that shock, he solved it for the second time. He seemed completely stumped by what happened. Then, perhaps to regain his cool, he suggested the following encoding for the solution code: for each cell you write how many neighbored edges are used by the loop, if the cell is a part of the U-Bahn network, you multiply that number by two.

After such stressful experience, he solved all five previous puzzles, each of them once again and even after that he solved the Expanding Skyscrapers three more times - that's how much he loves puzzles.

In the end he just looked at me and concluded - we really need a plan.

Part II. - Megaman vs Duck

As much as he loves puzzles, the Professor loves Megaman even more, and therefore it's no surprise he got this brilliant idea to turn the puzzle pack into a Megaman game.

You know, in case you never heard of it, Megaman is a videogame series where the main character, a robot called Megaman, fights other robots in order to get to robot masters with funny names.

That's really the main charm of the game, essentially you can go through a totally boring level listening to a terrible music theme, but everything is forgotten since in the end you fight a crazy robot with a cool name such as Search Man, Pharaoh Man, Wood Man, Tundra Man, Bubble Man, Plug Man, Sheep Man, yeah you got the point, you simply pick a random word and add "man" to it. Following this recipe, however the mundane or broken the actual puzzles are, no one will complain.

This gave birth to Megaman vs Duck.

This likely is the dumbest idea for a puzzle I ever had, but at the same time I just had to do it.

The good thing is that it is a standard fillomino, so you just divide the grid into orthogonally connected regions such that no two regions of the same size may share an edge.

After you are finished - or perhaps earlier, whatever you prefer - fill in each region with digits equal to its size.

The outside clues always come in pairs, one of them shows the total number of 0s while the other one shows the total number of 1s (which is which must be deduced by the solver), if you consider all numbers in that row/column expressed in binary.

Naturally, for the solution code, as the Professor suggested after he finished the puzzle, you should keep everything in binary as well, but otherwise, each cell has assigned its number as usual.

Naturally, in the true Megaman fashion, defeating each boss gives you just the right weapon to face the next one. So after defeating the Binary Man you gain the power of ones and zeros - the power of logic - and that's all you need to defeat the next boss.

Another crossing loop, but is this case, it might be just a matter of perspective. Here you are supposed to find a loop that moves orthogonally connecting centres of cells, is allowed to cross itself, but otherwise visits every cell exactly once. You are also supposed to fill in the grid with digits 1 to 6 without repeats in any row or column such that adjacent turns on the loop contain consecutive digits.

Now the big reveal is that the loop actually doesn't cross itself at all, what we see is just a projection of a loop that lives in three dimensions. Luckily this 3D loop - the knot - is quite restrained, each turn (in the projection) has the height equal to the digit in its cell and between those turns the loop moves in a straight line.

Some of the (supposed) intersections are marked by V or H. The H/V clue indicates that the horizontal/vertical part of the knot is the higher one at that (supposed) intersection point.

The Professor was so relieved after he solved the puzzle, so much he actually went on solving it for the second time right away.

The solution code he suggested: for a cell add the cell's digit and the corresponding digit from the loop - corner=1, straight line=2, crossing=3.

By beating the Knot Man you gain the power of untangling, especially useful for defeating the next boss, who is hidden in the center of a carefully entangled maze.

No digits are to be entered in the puzzle this time, here you just put one or more up/down/left/right arrows in every cell such that the arrows do not repeat in cages.

The number in the corner of the cage (if given) indicates the maximal number of arrows you are allowed to put within that cage. In the end, it must be possible to get from any cell to any other cell by following the arrows.

The Professor surely felt something is gonna go wrong again but still solved it with no hesitation. But right after that, perhaps to get in a better mood, he solved his now apparently favorite Knot Men's puzzle additional eleven times - how crazy is that!

Only then he suggested the following rules for the solution code: left=1, up=2, right=3, down=4, and if there is more than one arrow in the cell, you just write the digits in the ascending order.

After acquiring the power of Direction Man you learn how not to repeat a same mistake twice, which is all the knowledge you need to face the next boss.

No proper Megaman game would be complete, if there wasn't a stage which feels just like a repeat of a previous one. So once again in the Repeat Man's puzzle nothing is allowed to repeat in the cages.

This time you color some cells purple and some other cells orange. Then you draw a loop which connects orthogonally centers of cells and visits every uncolored cell exactly once.

Each orange cell must be inside the loop and each purple cell must be outside the loop. In any cage no two cells can be filled the same way (purple, orange, loop turn or loop straight segment).

Now, being well prepared from the previous stage, the Professor solved the Repeat Men's puzzle easily and then for a better mood he solved the Knot Man's puzzle once again. That still helped him enough as he was so relaxed he immediately suggested for the solution code: purple=1, orange=2, turn=3 and straight line=4.

Now the power of Repeat Man is to repeat the same thing over and over, and that will be very helpful in the next puzzle as you will need to fill in a lot of digits this time and even draw some snakes.

Fill in the grid with digits 1 to 7 without repeats in any row or column. Now for each arrow, the digits on it spell out the coordinates for the cell (the target cell) that contains their sum. The row number is written on the start of the arrow, the column number is written on the arrow tip.

And if this wasn't enough, each arrow has assigned a snake. This snake begins at the start of the arrow, travels through the tip of the arrow and ends in the target cell. The snake cannot contain the arrow sum except for the target cell. It moves only orthogonally and it cannot touch itself orthogonally. Snakes corresponding to two different arrows may not intersect.

Funnily enough, just when the Professor was going to start the puzzle, his toddler brother somehow got into the room and seemed to be really attracted by those funny little arrows. He started playing with them, occasionally even entering some digits in the grid. Clearly, the Professor is not the only one in this household, who can solve puzzles - to Professor's irritation apparently, as he now tried to finish the puzzle as fast as possible.

After he was done, and quite relieved his brother still had few more digits to enter, he suggested the following solution code: a cell has assigned its digit and you only add 1 if the cell is on a snake.

Just obtained power of coordinates will allow you to find the exact location within the a deep forest, where the last boss is hiding in his mysterious tent.

Draw a simple loop along the edges of some cells. Digits indicate how many edges of that cell are used by the loop. The loop divides the grid into regions. Each of those regions must contain exactly one tent.

A tent consists of two cells - a square and a triangle - connected and oriented in a particular way. The figure below shows all valid tents indicated by purple. For the purpose of the solution code, the digits indicate individual rows, the columns are defined analogously.

For the solution code - as the Professor decided after solving the puzzle - you just write for a cell how many neighbored edges are used by the loop.

The Aftermath - The Professor Shows Me How It's Done

Honestly, I thought he will try out some more, but the Professor said no to everything else - even to my zero sized region fillomino, even to my √πie-omino puzzle on a surface of a bicycle. No way.

Apparently the canonical number of stages in Megaman games is six, and also now is when the Megaman supposed to meet all the bosses again, in what is usually referred to as the Dr. Willy stage. Hmm. What did I get into. And it seemed to me the Professor had also one more reason to go through the puzzles again.

He started with the Repeat Man puzzle, but first he added a cage containing two cells, both in column 8, one in row 5 and one in row 6. Seeing that was not easy for me, as I completely missed that option. He solved it and looked quite happy.

He continued with the Binary Man, but again before starting he added an 11 ? clue to the last row. Seriously, again? He solved it with a smile on his face.

Then he went for the Knot Man but he solved it right away - no change needed. At least with this one I didn't fail so badly.

After that he chose the Coordinate Man. He casually shifted the given 1 two rows lower and only then solved it - and I felt totally embarrassed.

The Tent Man was the next one to come. The Professor scraped off all the 1 clues in one move and then he simply added 2 in the seventh cell in the second row. Just wow! He solved this one with a triumphant smile.

He seemed a bit nervous approaching the Direction Man - his nemesis. So before that se solved each of four modified puzzles and the Knot Man puzzle as well two additional times to get appropriately powered up.

Now, however, the time has come and the second meeting with the Direction Man was inevitable. The Professor didn't hold back at all, he removed the 3 clue in the last row and changed the 3 clue in column six to 2. Then he solved the puzzle, and even though it still was far from satisfactory, it somehow felt so clean and beautiful. Then, however, he reverted it back to the original version and solved that one too, perhaps for a direct comparison. We just couldn't decide, which one is less terrible, they were both flawed in just the right way it seemed.

And that was it, I felt we were finished, I hoped we were, after a humiliation like that, I felt I'm finished completely, that I will perhaps never make a puzzle again. I suggested we went outside for some fresh air. Little I knew the Professor wasn't finished just yet.

Suddenly, in the middle of the walk, he just stopped me and looked at me with his eyes piercing through both of his glasses. Then he said:

And that's how it's always with him. Half of the time he speaks normally, but at the other times it feels more like some kind of cipher or a different language or something. So when you think you have it all figured out, there is always another mystery right around the corner. Good that you like puzzles so much.

Also that is really the end, I resisted confronting the Professor about his stance on how solution codes should contain digits only - I just didn't want to ruin the moment of beauty before it fizzled out by itself few seconds later - and we both started laughing like crazy.