Can you make this Sudoku COLLAPSE ???

Added: 2026-06-04

[00:00:16]Hi, and welcome to Brimstone Puzzles, a channel where I showcase the fun that could be had in the world of variant Sudoku. And today, I'm doing a recommendation that actually came in from Full Deck and Missing a Few Cards.

[00:00:26]This puzzle is Ramshackle by Nicolas du Haut, who goes by NicoD on Logic Masters Germany. Um and this one is topical right now because this is an Arrows puzzle, and we're hopefully very shortly going to be releasing an Arrows puzzle pack on the channel. But um so I've been doing a lot of Arrows puzzles recently, but I'm curious about this one because this is something This looks really strange to me. Um and not just the coloring, the coloring is fine. Um but the way this is set up looks really weird. And I know uh Nicolas du Haut puzzle is going to have some very, very interesting things in it. So, I'm not sure what to expect. I was told this is going to surprise me. So, I'm looking forward to being surprised. Of course, there'll be a link below to where you can try this puzzle for yourself. Let's quickly go through the rules and see what we have. So, normal Sudoku rules apply, which means in every box, in every row, and in every column, the digits 1 to 9 must be placed without repetition. And then the sum of the digits along an arrow is equal to the digit in the connected circle. So, the sum of those two digits goes there. The sum of those two digits goes there. The sum of three three digits goes there.

[00:01:34]That's it. They're the rules of the puzzle. I'm going to restart the puzzle to restart my timer. Let's give this a shot.

[00:01:40]Okay, so the most obvious thing we have is the minimum that you could put into one of these. And I can see something more, but I'm going to go through the basics um because I'm explaining in a video. Um the minimum that you could put into these is 1, 2, and 3. So, because this is a minimum of 1, 2, 3, the minimum that you could put into any circle is 1 + 2 + 3. So, or at least Z circles that have these three cells where they all look at see each other.

[00:02:04]So, these are from 6 7 8 9, but they're actually more restricted than that because all of these are part of the same circle. And the minimum that these could be is 1 2 3 4 5. And if you add 1 + 2 + 3 + 4 + 5, that's 15. So, this or fit this has to be fit um 15 or sorry, if this was six, then how would I make this work? These would sum to 12, but the minimum is 15. And if this was seven, these would um these would so be 7 + 7, which is 14, but the minimum is 15. And the same is happening here, and the same is happening here, and the same is happening here. So, the none of these could be six or seven because minimum 15, six would make mean that they'd have to be 12, seven would mean they have to be 14. So, none of these are six or seven.

[00:02:56]And that's interesting. Can I do more than that?

[00:02:59]Now, the 1 2 3 4 5 in there was explaining minimums.

[00:03:05]What can I do now?

[00:03:08]Because I can't So, if they're eight, they sum to 16.

[00:03:13]And if they sum to 16, well, as I said, the minimum is 1 2 3 4 5. And in order to get from that to 16, I have to increase one of those digits 1 2 3 4 5 by one. And the only digit I can increase without causing duplication is the five to a six. So, if these if one of these is an eight, these are 1 2 3 4 6. Now, a nine is less restricted because I'm aiming for 18.

[00:03:38]Which it wouldn't need to have a one on it. So, there is a one in all of these because if I don't use a one, it's 2 3 4 5 6. And if you add 2 3 4 5 6, you're at 20. So, there is a one on each of these, but none of the rest of it's that restricted.

[00:04:01]So, how do you do this?

[00:04:09]Well, where's this digit in this column?

[00:04:13]This digit in the column, it can't be on an arrow that sums to itself because these are all Well, it could be if If we had an arrow that looked a bit like this, let's try and match the colors. If we had an arrow that looked like that in the grid, then these could be the same.

[00:04:28]You can have a digit on its own arrow, but we don't have this in this puzzle.

[00:04:33]What we have is this is two digits summing to that and three digits summing to that. So, you can never put this digit on its own arrows, and it can't be there because that would have it in the same row or box. So, this digit is up here.

[00:04:52]And the same is true here.

[00:04:54]That's an eight.

[00:04:56]This is an eight because where's this digit in this column?

[00:05:01]All right? It can't be in its same box.

[00:05:03]It can't be on its own arrow. It can't be If it was a nine, it couldn't be in either of those because this would be nine plus at least one and that would need to be 10, which it can't be. Same true here, nine plus at least one, that would need to be 10. Nine plus at least one, that would need to be 10. Can't put nine on an arrow.

[00:05:20]Oh, can't put nine on an arrow. That's a nine. Where's the nine in the column?

[00:05:24]So, this is an eight. And these are now 1 2 3 4 6. We've already discussed that.

[00:05:30]That's very cool.

[00:05:33]But, these [snorts] two digits have to sum to eight. Well, I can't use 1 7, there's no seven there. I could use 2 6.

[00:05:38]I can't use 3 5 because there's no five there, and I can't use 4 4, that's blatantly blatantly ridiculous. So, So only way with these combos with to do eight is with two six on the two arrow and one three four on the three arrow.

[00:05:53]So if you ever get eight in any of these, it has to be two six and one three four.

[00:05:59]So [snorts] if this was an eight, this couldn't Oh, no, this could be because the two sixes don't see each other. I could actually possibly go eight eight eight eight. That's very strange.

[00:06:10]These would all be one three four. Is that a problem?

[00:06:15]I don't think it is, but these digits are now restricted. I've got one two three four. I don't have five seven or eight.

[00:06:26]So one of these has to be an eight.

[00:06:31]So one of those has to be a nine.

[00:06:35]How do I use that?

[00:06:45]Wait a minute.

[00:06:47]What can that be?

[00:06:50]I think this has to be a nine.

[00:06:54]Cuz if this wasn't a nine, what would I put here?

[00:06:57]If this wasn't a nine, it can't be an eight. It have to be as low as a seven, which means both of these digits would have to be lower than seven because we're adding something else to them. But I've only got one digit lower than seven.

[00:07:08]So if this is as low as possible, five seven, these both have to be higher than seven, but I've only got one digit higher than seven, which is nine. So these the one that goes with the five is a four, the one that goes with the seven is a two, and the one that goes with an eight is a one.

[00:07:24]So this is nine eight. A nine in this column can't be in any of those and can't be on an arrow. That's a nine.

[00:07:30]Which restricts that.

[00:07:42]This is weird.

[00:07:50]So, where's eight in this column?

[00:07:52]That could be the No. Where's eight in Oh, this is nuts. Where's eight in this column? It can't be where the nine is.

[00:07:59]It can't be here cuz the minimum would be eight plus one making that a nine, which it can't be. So, there's no eight there. I can't put eight on a three-cell arrow cuz if I do, the minimum would be 8 1 2, which is 11, and I can't make that 11.

[00:08:14]Eight can't be here because I've got an eight in the box. So, eight is in one of those three, which means there's no eight here. So, there's no one here.

[00:08:22]This is 5 7 2 4.

[00:08:27]Now, well, the 5 7 is looking down making that the eight.

[00:08:43]And this has to be 8 1 9, the absolute minimum it could be, which means there's no one in either of those. There's a one here.

[00:08:51]And this is a 3 4 2 6 5 7. One and one puts one up here.

[00:08:59]>> [snorts] >> Oh, one is up here. So, the minimum this could be is 2 3 4 cuz I can't put one in either any of these. And 2 + 3 + 4 is nine.

[00:09:12]So, that puts nine and nine. Nine is in Oh, the nine looks up making this an eight. And we've already discussed if one of these is an eight, then the only way to do that is a 2 6 on the two-cell arrow and a 1 3 4 on the three-cell arrow. And the one can't be there.

[00:09:35]The 3 4 makes that the two taking the two out of those. That's a three-four.

[00:09:41]So, this is a triple, five, six, and seven.

[00:09:47]And the minimum here is two, but the maximum is four. So, this is two, three, four. And it can't be four cuz if this is a four, the minimum would be five, four, and that would need to be nine.

[00:09:55]So, this is only a two or a three.

[00:09:59]And the minimum here is seven with five plus two. So, that's a seven or an eight.

[00:10:05]Five plus two. And if this was a seven, this can't be a seven. If this was a seven, the minimum would be seven plus two, meaning that would need to be a nine, and it can't be. This is a five or a six, putting seven in one of those two.

[00:10:18]Which means seven can't be in any of those. Seven can't be in any of those.

[00:10:22]That's a three-four. That's a seven.

[00:10:28]So, in this column, how do I make this Oh.

[00:10:32]This always had to be one eight. Well, since I got the one and the eight up here and that being a nine, because if this wasn't a one eight, yeah, one of the digits one and eight has to be on the arrow because I've got to put two digits into three cells. And there's this suction effect that happens. As soon as a one is on this arrow, it sucks the eight in with it.

[00:10:51]And as soon as the eight is in this on this arrow, it sucks the one in. So, because I have to put one of the digits one eight on this arrow because I can't put both of them in that cell, it sucks the other one in, and that becomes the one eight.

[00:11:05]So, this is a five or a six but to finish the column, and the five-seven makes that the six, that the five, which does allow for either two or three. But, that takes five out of those, and that's a six-seven.

[00:11:23]Oh, the six makes that the two, that the six.

[00:11:26]So, these, one, two, three, four, five, six, seven, eight, nine. These are three and 4, and 1 2 3 2 and 5 go into those.

[00:11:39]This is really cool. And the weird thing about it is none of these feel like they collapsed.

[00:11:47]The six makes that the two and that the six, which makes that the five and that the two.

[00:11:54]Six and six puts six in one of those three.

[00:12:00]If that's a six, it has to go 1 7 2.

[00:12:03]Cuz I can't go 6 2 8.

[00:12:11]I don't see a problem there. If that's a six, this would have to go 2 1.

[00:12:18]And that would be a nine.

[00:12:22]And that would work cuz I could go 6 2 1 and that could still be a 4 5.

[00:12:27]Oh, the two makes that the four, which means that's the five, that's the seven, that's the two.

[00:12:40]Nine is in one of those two by Sudoku.

[00:12:48]Eight is in one of those two by Sudoku.

[00:12:52]Two is in one of those two by Sudoku because of the two looking across and the two twos looking down.

[00:13:06]Can that be an If this is an eight, it has to have a one on it. If it's a nine, it could be 2 3 4 still.

[00:13:17]And that would be 1 8.

[00:13:21]Don't see why that doesn't work.

[00:13:29]>> Hmm.

[00:13:36]Typical brimster.

[00:13:38]Get some really good flow and then face plant straight into a brick wall.

[00:13:43]Okay, this is under some constraint because two and four aren't available.

[00:13:49]So the this is a minimum of four with one three. Oh, hang on. So what is this? 4 5 6 This is four or eight only.

[00:14:05]Oh, and the eight makes that a four.

[00:14:08]Because the only digits available it has to be at least four with a minimum of one three.

[00:14:14]So four five six seven eight five six seven eight nine. This is a four. So this is a one three.

[00:14:23]And that does some stuff because now where's one in this row? Can't be in any of those, can't be in any of those. One is up here. Where's three? Can't be in any of those, can't be in any of those.

[00:14:34]Three is up here.

[00:14:43]The four makes that the three, that the four. The three makes that the one and that the three. The one makes that the eight and that the one. And the eight means that's a nine.

[00:14:54]One eight works, three six works.

[00:14:57]But this is a triple.

[00:14:59]Five six and seven.

[00:15:03]Well, that didn't do much.

[00:15:05]The six comes out of there, so six is in one of those two.

[00:15:19]It's a one three pair.

[00:15:21]One three can't go in either of 1 3 can't go in any of those. That's an eight. This is a 1 3 pair. So, this 1 2 3 4 5 7 9. These are 5 7 and 9. There's no nine there.

[00:15:42]There's [snorts] an eight in one of those two for the column.

[00:15:46]Eight. Not there. Eight not there.

[00:15:48]That's eight not eight not there. That's eight in one of those two.

[00:15:56]So, in this row, 1 3 Yeah, 1 3 8.

[00:16:01]In this row.

[00:16:03]And that can't be an eight because the minimum would be 8 1 2, which is 11, not nine.

[00:16:09]So, that's an eight.

[00:16:14]Can I still put eight on this arrow? I think I can.

[00:16:20]Eight is in one of those three.

[00:16:27]These sum to nine now.

[00:16:31]So, [snorts] 1 2 6 works.

[00:16:36]1 3 5 works.

[00:16:43]2 3 4 also seems to work.

[00:16:57]Huh.

[00:16:57]>> [sighs and gasps] >> Oh.

[00:17:19]1 3 4 1 3 4. These are 1 3 and 4.

[00:17:23][snorts] So, this is restricted.

[00:17:28]That's a 1 3 4 triple. So, that's the eight.

[00:17:32]Cuz 1 2 3 4 5 6 7 These are a 5 8 pair, but the eights are looking up. So, that's the eight, that's the five. The five makes that the seven taking seven out of both of those, and this is now a triple.

[00:17:45]2 7 8 Well, there's no eight there.

[00:17:52]Let's finish this off, but I'm going to come back and look at this arrow in a minute. 1 2 3 4 5 6 and 9 go into those.

[00:17:58]The six looks up making that the nine, that the six. So, this is a pair. 1 2 3 4 5 7. These are five and seven.

[00:18:07]And that puts seven in one of those two because seven can't be in any of those cuz of the 5 7. It's not in any of those, and that's not a seven cuz I can't go 7 1. So, seven is in one of those two making that the eight, which is 5 3.

[00:18:20]And this I'm not sure. But, let's look at this. 8 1 works, 7 2 doesn't, and 2 7 doesn't.

[00:18:27]This is 8 1.

[00:18:29]Which means this is three, and this has to be 2 4 because the minimum this could be without a one is 2 3 4 something to nine. So, this is a 2 4 pair, which means that's not a six.

[00:18:41]And the two looks across making that the four, that the two.

[00:18:44]Very nice. The three looks across making one and three. The three looks across making four and three.

[00:18:52]And these have to sum to eight.

[00:18:55]Well, that can't be a six cuz if it's a six, that would have to be a two, and it can't be. So, that's not the six, that's the six. This is a triple. 1 5 7 A one would need a seven, seems okay. A five would need a three, which doesn't work. And a seven needs a one. So, that's a 1 7 That's the five. That's not. The five looks up making six and five.

[00:19:17]The three and the one look up making that the four. That's not the four. The one makes that the three.

[00:19:23]The eight comes out of there. The 17 looks up making that the two and that the seven. This is really not I keep coming back to there's just so many puzzles that are beautifully elegant without being diabolically diff- difficult and so few people solve them.

[00:19:41]The um the five looks across making that the seven taking the seven out of those.

[00:19:45]The five looks down making that the nine, that the five.

[00:19:48]And we've got triples all over the place. The seven makes that the one taking the one out of there. The three-four pair makes it that the one.

[00:19:56]The seven looks down saying that's not the seven, that's the seven. The three looks across making that the four, that the three, which makes that the four, that the three. Let's look at this column. 1 2 3 4 5 6 and 9 go in. The nine makes that the six, that the nine, which makes that the seven, that the six, which makes that the five, that the seven. I've done all the arrows now. So, 1 [snorts] 2 4 5 go in. The four and the five means that's the two. Take the two out. The four means that's the five, that's the four. 1 2 3 4 5 6 and 8. 2 6 and 8 go in. I'm going to remove all the corner marks. The two and the eight make that the six. Take out the six and I'll use either the eight or the two to make that the two, that the eight. And that puzzle. Congrats. I hope you enjoyed. I absolutely did.

[00:20:46]That breaking with first of all with where the nine is in this column, but I didn't even see that at first. It was like, "Where is this digit in this column? Where is this digit in this column? Where is this digit in this column?" And the interactions of that.

[00:21:00]Very cool.

[00:21:03]That's a really nice puzzle.

[00:21:05]We've got puzzles that are easier than this in the pack and we've got puzzles much, much harder than this in the pack.

[00:21:11]But yeah, this would have stunning.

[00:21:15]We've got puzzles that use tricks very similar to this in the pack, but I think this is using it in a way that is very, very different to some of the stuff we've done. But there's one by Mixol that is harder than this, but it has just similar in concept but just beautifully done. But this is all about Nicolas Du Hales' puzzle and that one is great.

[00:21:36]Yeah, it was >> [snorts] >> You don't need to make a diabolically hard puzzle using a novel constraint in order to come up with something beautiful. That is absolutely beautiful.

[00:21:49]Thank you everyone for watching. I hope you enjoyed this as much as I did. I may be taking the weekend off. I'm not sure yet or you may see a couple of puzzles from Full Deck and Missing a Few Cards.

[00:21:58]I don't know yet. But either way, thank you everyone for watching and as always, good luck with your solving.

[00:22:06]>> [music] [music]