The Viper In The Fog

** TODAY'S PUZZLE **
Lots of you enjoyed yesterday's Fog Of War sudoku by Oddlyeven so we thought we'd try another one today - but this one is a little harder. It's called Viper In The Fog and it's by Jolly Rogers. It features a very original ruleset and some absolutely lovely logic! Enjoy.
Play the puzzle at the link below:
sudokupad.app/23fMD676d3
Rules:
Normal Sudoku rules apply. The grid is partially covered in fog. Correctly placed digits will clear the fog around that cell. No guessing is required. Digits in a circle must appear within the four surrounding cells. Draw a single one-cell-wide snake of orthogonally connected cells which begins and ends in Box 4. The snake can touch itself orthogonally and diagonally but must not branch or overlap. Box 'N' must contain 'N' amount of snake cells, and within this Box ‘N’ the digit 'N' must appear on the snake. (Boxes are numbered in normal reading order.) Eg Box 5 must contain exactly 5 snake cells, and one of these snake cells must be the digit 5. Box borders divide the snake into segments which sum to either 1, 5, 10, 15 or 20. Cells which are not part of the snake must be able to orthogonally connect to the grid boundary.
** THE LORD OF THE RINGS SUDOKU HUNT RELEASED ON 1 JUNE **
We've just launched the sudoku event of the summer! Blobz' puzzles and Ted Nasmith artistry combined in one of the most beautiful, approachable and fun hunts we've ever published. Get hyped!!! Teaser puzzle here:
sudokupad.app/blobz/a-long-ex...
Play the full version here:
/ crackingthecryptic
Other treats on Patreon include:
- Simon's solve of Sky-Skyscraper by Phistomefel has just been uploaded for our patrons.
- and Mark's latest solve of The Times Club Monthly cryptic crossword
** LAST NIGHT'S BRAID STREAM **
You can watch our stream from last night at this link:
kzbin.infoWcqUhQkwUSY
▶ SUDOKU PAD - Use Our Software For Your Puzzles ◀
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▶ Contents Of This Video ◀
0:00 Theme music & puzzle intro
1:12 600,000 Subscribers... IMMINENT!
2:12 The Lord Of The Rings Sudoku Hunt stats
2:49 Happy Birthdays & Fathers Days
4:41 Rules
9:27 Start of Solve: Let's Get Cracking
▶ Contact Us ◀
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[@mikoajgutowski7747]

Someone needs to make a Sudoku puzzle with nothing to reveal under the fog. Simon will surely greatly appreciate it and be very satisfied with revealing it.

[@HunterJE]

Ooh that's devious, so like a blank-grid miracle ruleset but sold as a fog puzzle?

[@Quintinohthree]

​@@HunterJEBonus points for an extremely long ruleset and double bonus points for any negative constraint.

[@pascal6871]

All black dots are given fog without any black dots 😂

[@aithne99]

@@pascal6871 That was surely a glorious solve.

[@iceberg54321]

Kinda already did that, it wasn't great. The fog just makes the puzzle solve less stressful.

[@mikebarta4887]

Amazing that there was so little under the fog to force this to a single solution

[@Cid0484]

When he explained that there could only be two 7s in the last two rows, I was absolutely certain he was going for the 7 in column 9. The fact that this 7 took him almost another 15 minutes, is one of the things why I love Simon 😂

[@KurtHugoSchneider]

this puzzle is almost completely solvable without the 'pond' rule (where non snake cells must be able to get to the wall)... i overlooked this rule when i solved the puzzle, and found the solve path to be completely brilliant!! the start of the solve i imagine is similar but after determining the snake had to have 4 entrances/exits to box 7, you could eliminate the case of 3 entrances coming from box 8 since it prevented the snake having 8 cells in box 8 (with an elegant interaction from the 5 in box 9) and you could eliminate the case of 2 entrances from box 4, with a beautiful interaction involving the 1 in box 1! the grid can be almost fully filled but i couldn't untangle the possible snake path in box 8, until i reread the rules... it kinda makes me sad though because the intricate logic used to fill the grid wasn't necessary or even intended if you use the pond rule :( if anyone wants an adventure you can try to not use the pond rule until you've determined the snake path through every box other than box 8! it's beautiful i promise!

[@philwheatley5057]

I completely forgot that rule and finished in 32 minutes

[@bait6652]

Try finishing it without revealing fog

[@Alezyy]

I would have NEVER expected you here, what a crossover

[@pouletbelette]

​@@Alezyy Kurt has even appeared on the channel as a setter once. He's a long time friend and viewer of Cracking the Cryptic.

[@colej.banning2419]

​@@pouletbelette I only even recognize his name from CtC. I think Simon said he does music?

[@HunterJE]

33:40 Another interesting thing to note about the "pond" at this point is that it must reach the edge by way of box 4, and while there must pass between the "head" and "tail" (if it doesn't it will form a barrier keeping the snake from completing)

[@objectshowfan362]

I just finished an especially exhausting 30 minute walk (I'm trying to pull myself away from gaming and be more active) to this video in my recommended. This is the perfect video to watch whilst taking a rest from that walk.

[@mikoajgutowski7747]

Keep it up, healthy gamer!

[@objectshowfan362]

@@mikoajgutowski7747 Thanks for the encouragement, but I don't need it. Self-discipline keeps me going. I felt tired after 10 minutes, but went for 30 anyways because I committed to 30 beforehand and thus stuck with it. Motivation is fleeting, but self-discipline is forever.

[@Pathogenus]

i love those fog of war puzzles that subvert expectations and make you look elsewhere than a revealed clue

[@chris5619]

Happy birthday @SvenCodes!

[@ocularzombie6679]

no freakin way mine is tomorrow that's so crazy

[@dontmindme2844]

Wait??? Simon using blue for a pond of water? Inconceivable!!!

[@dylanlenn7836]

I do not think that word means what you think it means

[@piarittersporn]

It took me ages ... especially in box 8 .... to work out the snake, but it was an absolutely great and exciting puzzle.

[@MatthewBouyack]

Absolutely brutal! This one took me almost five hours! I found it very difficult to narrow down the possible snake paths in boxes seven and eight. Quite happy I was able to (eventually) get it done!

[@Zeekfox]

I love the premonition from Simon at 57:22 of people shouting at him why something is incorrect. However, it's not the snake connection he just made, but the one before where he drew a 5-cell segment in box 7 that must contain the digits 7 and 9 by circle rule, 7 plus 9 plus three other digits (at least 6 in total) is greater than 20. But Simon doesn't catch this flaw in the way he drew the snake at that moment.

[@ericpraline1302]

Not mad keen on snake-type puzzles generally, but thought this one was really nifty. Setters really are continuing to show great creativity.

[@HunterJE]

The real challenge of this puzzle is trying to say things like "six snake segments" without getting your tongue too twisted

[@maljamin]

sakes snig sneckmints. there.

[@titusadduxas]

1:26:11 - Wow! Discovering that snake idea must have been hugely satisfying. Well done Jolly Rogers! Brilliant puzzle.

[@josephlewis7945]

it pains me that he didn't see the 1 digit in box 1 sooner

[@Crocodile_Appreciator]

I mean, he was cooking in box 9 before it, so it's not like he was wasting too much time

[@Roblilley999]

First thing I saw

[@gi0nbecell]

About that: Did I miss something in the rules that said the snake had to visit every box? I get Simons reasoning about the snake _if_ it visited box 9 at all, but I didn‘t get why it was forced to do so from the get-go. Same goes for box 1: Sure, _if_ the snake visits box 1 it can only do so in r3c3, which then has to be a 1 (and the snake has to continue to r3c4 and r4c3 to not take any more cells in box 1), but why does it _have_ to visit _any_ box besides box 4? As I read the rules, it could be a very short, 4-cell snake containing the digits 1 through 4, all contained in box 4, making the puzzle essentially impossible to solve.

[@josephlewis7945]

@gi0nbecell in the rules it says box N has N number of cells on the snake so the snake has to visit every box

[@djekhex]

@@gi0nbecell "Box N must contain N amount of snake cells". if you put 0 snake cells in box 9, 0 does not equal 9 so that would breaks the rules.

[@Hakucho64]

Wow, what a puzzle. Nearly gave up a couple of times, but kept on plugging away trying different things (lots of what-ifs) and eventually got it out.

[@frankjiang1857]

Finished in 77:07. I go the snake in about 40 minutes, but then spent the next 30+ minutes trying to figure out the sudoku and forgetting the last rule of the puzzle. Fun puzzle!

[@homestar92]

I really like how it took the realization that the triangular number for 7 was too high before Simon realized that the water didn't all have to connect to *the same* boundary cell.

[@NormalTheBand]

The easiest way to describe "orthogonal" is simply that it is the opposite of diagonal. Highlight the 4 orthogonal squares and mention that they are not the 4 diagonal squares. It's a very clean explanation

[@Sponsie1000]

l guess, but it feels less clean imo to explain a term by pointing out what it isnt. Also this wont be an issue for square grids like sudoku, but in general your definition would kinda break if we were to apply it non-square grids (triangular/hexagonal/etcc). In contrast, "Two cells sharing an edge/side" is pretty clean/simple to understand and it's true for any grid :]

[@RichSmith77]

​@@Sponsie1000If anyone were to try to claim connections along an edge in a triangular or hexagonal grid were in any way orthogonal, I think I'd rage quit the puzzle immediately 🙂. Orthogonal connection ends up meaning "connected along an edge" *because* it's a square grid. It's a simplification that applies in the case of a square grid, and no other. (A mathematician or lexicographer would also say that a snake that ONLY connected along diagonals, technically also only has orthogonal connections. It's just "orthogonal" has come to mean something else in the sudoku world.)

[@istvanmagi473]

I don't think there is any need to explain this word. Simon does it as a meme. And it gets longer and longer every time-

[@NormalTheBand]

@@istvanmagi473 I think thats disingenuous. Simon does a great job teaching concepts every video just in case this is the first CtC video one might click on

[@SunnyJJC]

I'm halfway through this puzzle but its already one of my favourites featured on the channel

[@pascal6871]

This was a really entertaining solve. Especially cool was how all the rules kept veing relevant at all stages. Often rules only matter for the break in or clarify edge cases but not here. Great puzzle and video

[@emilywilliams3237]

This was very interesting. Especially interesting was what you discovered at the end, that practically nothing was actually hidden under the fog. I think that the rules of the puzzle did the work, and the fog was just like an extra layer of frosting for Simon! Thanks for the video, Simon. I had to watch this one in segments, but I am very glad I returned to it to see the entire thing!

[@chocolateboy300]

I finished in 209 minutes. This was one of the hardest puzzles I have done. I had some intuition about the puzzle, but it was so hard proving that it was correct. At some points, it felt like I was going around in circles. I pushed through and was able to complete it. It was a lot of fun, but proving that bottom section was really hard. Great Puzzle!

[@longwaytotipperary]

Happy solstice!! Happy foggy puzzle day!!

[@warren_r]

Very very happy with my 61 minute completion time. What a puzzle!! The logical steps required to figure out the path through box 8 is a real standout for me.

[@xXFoiXx]

This one would be a lot more fun to play if we could also draw those lines.

[@CPTEP46]

I want to know if constructors are intentionally putting 3’s in the corner, just to make Simon happy.

[@SirBradiator]

26:27 I would always work on the assumption that if the constructor needed you to know what was in the circle they would have constructed the clue to be fully revealed rather than partially hidden.

[@Mephistahpheles]

@41:07 I'm particularly amused when Simon puts the mouse *exactly* on the thing he doesn't see.

[@Mark199201]

Hi Simon/Mark! Did you hear the PM programme with Evan Davies on Radio 4 yesterday (19/06/24)? At approximately 51 minutes 40 seconds Dave Gorman and Katie Steckles were discussing cryptic crosswords and whether the clues were getting too old without youthful references! You might find it interesting! I'm not sure I can post a link, but it's on BBC Sounds

[@Hakucho64]

I often think that about the cryptic crosswords in the Sydney Morning Herald. Luckily I'm the exact demographic to understand all the necessary slang and cultural references! 😛

[@MattYDdraig]

There was a Guardian article yesterday or the day before on this subject also, with quotes from Mark, and a mention of CtC.

[@MattYDdraig]

34:54 Stunningly good, especially the devious slithering in box 7!

[@paulellingham9358]

Clean up our snake and think harder 😂😂 So innocent.

[@CauchyIntegralFormula]

48m10s. That sum condition was much more powerful than I initially realized!

[@Stompound]

This is possibly my favorite fog of war sudoku of all time

[@daavor]

I have to agree with Simon that one of my pet peeves/worries with these types of fog puzzles is whether I'm expected to recognize a digit from it's bottom half. I much prefer the "quad with ?" approach that lets the constructor force certain digits to reveal in certain squares fully.

[@gregind01]

It was great listening to Simon hiss along to his commentary with statements like "sssixss sssnake sscellsss in boxss sssixss". 😁

[@britlion]

1:12:40 I can't resist pointing out that Simon is presumably confusing Doctor Spock, the childcare chap, with Mister Spock, the star trek logician. And yes, I'm a pedant.

[@user-jw8ey4fv1l]

I have a question, but I don't know if you have answered it. So, have you ever gotten stuck on a puzzle, and if yes, would you consider trying it again? (Awesome videos, and even though solving them is fun, watching you is very entertaining)

[@efa666]

25:03 kinda disappointed that Simon didn't do some paraphrase of "that's a Smith and Wesson, and you've had your six".

[@puritan7473]

Congratulations, Happy Birthday Sven!!

[@johnh2052]

At 56:30, Simon draws a plausible line distribution of box 7. The reason this fails is that the 5-cell line includes both 7 and 9, meaning it's a minimum of 22. EDIT: Never mind. He sees exactly this issue 8 minutes later.

[@JohnDBlue]

"That might be fine" is such a Simon thing to say after putting in a possible snake path that creates an ending for it in the wrong box 😅

[@anaayoung9142]

Ssssssspecial ssssssudoku for ssssssssure! Thanks for the ssssssolve! 🐍😅

[@grahamania]

00:56:42 for me. Amazing puzzle. Loved it from start to finish! Kind comment.

[@colej.banning2419]

1:12:44 "the ultimate finder of Dr. Spocks" It attracts a lot of pediatricians?

[@gencolik]

New song idea for snake puzzles Simon. "Unsnake my heart, say you love me again"

[@PhilBoswell]

Hard to believe I'm the first to say this, but *Dr* Spock was a paediatrician (or possibly a pediatrician, I think he was American ;-) whereas the person to whom you refer is *Mr* Spock…

[@Nerdnumberone]

I wonder if the fog made this easier than seeing the scant circle clues.

[@angec9908]

Simon not wanting to say something illogical because it brings out the “Dr. Spocks” which itself it illogical because Dr. Spock was the baby doctor and /Mr./ Spock was the logical Vulcan 🤣

[@michaelmatter1222]

Exquisite!

[@stephenmccarthy1795]

Chevron effect is lovely. Simultaneously funny, beautiful, impressive, and annoying.

[@Timlagor]

I keep being incredibly clever and getting nowhere!

[@Yttria]

Tough one, although half of that was me missing a couple obvious things including the part of the rules that required the snake to start and stop in box 4. Finished in 127:24.

[@marcbennett9232]

it is absolutely insane to me how few likes you guys get compared to how many subscribers you have.

[@RecreationalCynic]

Did it in 54:31. Happy birthday, Sven!

[@ronjohnson6916]

Neat. I'm terrible at snake logic but for once could follow all of the logic. The rules constrain the path in a way that was not at all apparent on first viewing.

[@caffeinemonster7242]

@01:12:44 - Mr Spock, not Dr. Spock (He says, proving your point 🙂).

[@mrtrunin]

It’s going to be one good video. I just know it!

[@craigfjay]

47:50 This idea wouldn't work because box 8 would have 2x single segments containing 1 and 5, both being in row 7 which already has a 5 in

[@57thorns]

33:47 was the last deduction I managed before derailing. r4c4 has to come out, forcing the snake composition of box 5. Because if r4c4 is snake then r5c4 also is snake amd the fifth cell is r6c4 and the pond is surrounded.

[@srwapo]

70:58, lotta time spent just looking for what to do next, seemed like thinking about the sums of non-snake cells were super important. I thought I broke it for a while before realizing that I only saw the bottom of the second digit of the clue in box 3 and what I assumed was an 8 could actually be a 6.

[@imsquash2581]

This is sports for me.

[@douglasmagowan2709]

At minute 33. The top left cell of box 5 (R4C4) cannot be snake. And then the center of the box cannot be snake, giving all of the snake / not snake cells in the box.

[@donaldsnyder1543]

Viper in the fog ? 😮 I guess we've been introduced to the three most dangerous letters in sudoku , R.K.O.!

[@peterhowitt3861]

21.01 - surely R3 C4 and c5 could have also been a 7/8 pair adding up to 15

[@carlscheuermann3684]

at 57:45+, Simon draws three border crossings between boxes 4 and 7 and immediate concludes R6C3 has to be a corner, so he connects it. But couldn't it have been the end of the snake? (For as much as he knew at that point in the solve...)

[@bobblebardsley]

I'll be honest, when Simon said he was going to start in box 9, I thought he was going to colour in the whole box and then look somewhere else 😅 How very wrong I was...

[@jonkess2768]

At 58:43 i feel like he explored both versions of the world and both versions are indentical in box 4? So whatever happens with the snake C3R4 has to be a snake end 5 and C1R6 has to be snake end and a 1 and C3/4R6 have to be connected by snake. Ok he noticed it shortly after :)

[@oddbarnett]

41:17 - Dooh-Dooh

[@jinkela7295]

A little surprised that Simon's first digit is not the 1 in r3c3 lol

[@michaelhoffman2443]

I missed the one "important part" of the clues which say the snake starts and ends in box 4... and I am watching the video thinking, "How is Simon so confident that the 1 isn't a snake end.... how is he so confident that the 9 isn't a snake end" lol... I will try the puzzle myself again now with that added knowledge lol

[@Rach881101]

51:42 for me. Nice puzzle!

[@Tepalus]

49:14 for me. Not too difficult. Once you get certain restrictions and implications the puzzle has a very nice flow. :)

[@Kirbyfan87827]

Finished in 47:16 with help from the video.

[@karlmortenlunna2417]

26:12 for me today. Nice puzzle!

[@Gonzalo_Garcia_]

25:05 for me. Fantastic puzzle!!

[@MaxPower2719]

19:08 Well, that was anti-climactic 😂

[@PhillyMotoXTS]

How do you put the lines and X and O in?

[@tessabrisac7423]

The first icon in the first column under the grid takes you to the settings; click on the first option, “pen tool”, and you’ll have these tools enabled on the right side of the number pad.

[@angec9908]

I cleared all the fog and then got stuck in box 7 based on the math and then I finally realized there was an alternate path 😭

[@Hakucho64]

Normally these variant rules are clear to me, but I'm struggling with the one that says "box borders divide the snake into segments which sum to either 1, 5, 10, 15 or 20". Does this mean: A. the segments _collectively_ sum to one of those numbers, or B. each segment in a box _individually_ sums to one of those numbers? I suspect B, but only because there are more elegant ways of expressing A, for example "the snake cells in each box must sum to 1, 5, 10, 15 or 20". However, confirmation would be nice.

[@Hakucho64]

Also, thinking about it some more, I suppose box 9 could never satisfy condition A, so it must be B. They might have added the word "each" to clarify this, i.e. "segments which _each_ sum to either ..."

[@NaHBrO733]

1:13:00 While it was infuriating to see Simon not able to deduce what those snake segments are, there is actually no way to continue other than finding the 9 in box 6. Even at 1:17:00, the best you can do is notice the snake in box 6 cannot be 23 (because the short snake in box 5 cannot be 46 anymore), and must sum to 10,10,15 with those two 10's are the same. I was stuck there again before finally finding the triple.

[@stangerrits6712]

Quite easy to do some math on row 6, if only Simon would know the secret 😂

[@six_5000]

No clue how to even start. Put four 3s in the corners and gave up

[@DanielCoto93]

Simon missing the 1 in Box 8 for so long hurts me

[@RhiannonAgutter]

I somehow managed to do this in a miraculous 43:11 and I have zero idea how

[@peterhowitt3861]

21.01 - I'm wrong, it had to include 2. Duh!!

[@Paolo_De_Leva]

Intriguing ruleset. I am looking forward to solve it and I bet it will be phenomenal. Thank you Simon for featuring it.

[@RoderickEtheria]

I kept forgetting to consider the length of each snake segment, or I should have done better than my around 48 minute mark.

[@theredstoneengineer6934]

46:54 for me

[@_koXx_]

I am missing something essential in the rules: It isn’t mentioned that the snake has to visit every box! So, how could you start the puzzle in box 9 if you cannot assume that the snake actually visits that box?

[@stangerrits6712]

You're absolutely right, I saw the same and was expecting much more comments on this!

[@ubk-qm4rz]

Doesn't "Box N must contain N amount of snake cells" imply that?

[@stangerrits6712]

@@ubk-qm4rz For many readers it may suggest that, but strictly speaking it’s not correct I think. You can also interpret it like so: ‘for every box the snake visits, it should have N cells, where N is the number of the box’. It’s not stated that the rule of N cells in box N has to be applied for all box numbers.

[@_koXx_]

That was my initial understanding of the rule as well: If the snake visits box N, than box N has to contain N snake cells. It was only after I couldn't solve the puzzl that I concluded this rule might have a different meaning. The need to assume something like that is in my opinion not suitable for a logic puzzle though.

[@nicka3697]

Happy unbirthday Simon

[@bruceh8043]

1:00:00 for me and solver #3425.

[@Roblilley999]

66:02, not an easy one

[@MPedlar]

Mr Spock….

[@mrtrunin]

First!

[@Windgonner]

No Snakes Please 🤮🤮