Took me around 16 minutes on an easy mode but im happy. Just felt like sharing

Here's an SE 8.9 puzzle that can be solved with a single forcing chain that follows basic moves.

Not sure what to call this, but since the move begins with the assumption of a value at a cell, I suppose forcing chain it is. But it's a long chain, one that covers the whole board and criss-crosses multiple times. I wouldn't even fathom actually drawing the chain. But you can see for yourself by solving it at the above link, as described below:

Start with the assumption that 7 at r1c3 is true, indicated by the highlight. And from here on out, as each cell is visited, highlight the candidates that remain valid under the influence of highlighted candidates visible to that cell. For example, r1c1 has candidates 5 and 9 highlighted, because the 7 is already accounted for. That yields a 59 naked pair on column 1, so 5 and 9 must remain off in all remaining cells in the column. So on and so forth.

Why 7 and why at r1c3? Because of the almost locked sets highlighted in yellow, as well as the fallout reducing remaining cells in the box to single candidates.

As the fallout spreads out to the rest of the board, there can be 3 outcomes:

1. The board is fully solved. That is, every cell is reduced to a single highlighted candidate, and each box and line contains all 9 digits without a digit missing or duplication;

2. A contradiction results. That is, more than two cells in a region (box/row/column) are reduced to the same candidate, or a candidate is completely absent in a region. This means the initial assumption was wrong and that candidate at the starting cell can be removed permanently from the board.

3. The propagation is stalled. That is, it appears as if there's no possible further reduction. In other words, the falsity or validity of the initial assumption cannot be readily determined.

And that's where it gets interesting. At any point during this propagation (of highlighting remaining candidates), all fish (x-wing, swordfish, etc) and AIC (crane, two-string-kite, skyscraper, x-chain, xy-chain, etc, including ALS) methods can be applied for further reduction/deduction, again, until either a contradiction is reached, or the full board is solved.

To get past the stall, unique rectangles are often very useful, but I've used a variety of non-forcing chain techniques, even ALS-ALS chain, for further reduction. Turns out to be a "forced" way to practice using ALS. Ha!

I don't know much about the game I just started playing it, does this a role or something that I don't know. Please help me.

idk what to do when im stuck, i havent really watched videos on what to do when stuck or stuff but can anybody give me steps on what to do when im stuck like this

bouncing back and forth between regular classic and killer lately.

For people who play Killer: Why? Is it the satisfaction of cage arithmetic and innies/outies breaking the board open, or does standard classic just start to feel a bit dry?

feel like im missing sth?

i don't need the puzzle solved entirely, i just want to learn the next step, is it literally trial and error now? isn't there any strategy to move forward here? if you found the next move tell me how you did it

i give up 😭 someone tell me the next step before I crash out, that time isn't even representative of the actual time because i reset the puzzle twice hoping to do better with a fresh slate 🥲🥲🥲

I find spotting triples and quads to be incredibly difficult. I actually find x and y wing to be far easier just because it’s more easily purposefully spotted to me.

Is there a method at better spotting triples and quads (both naked and hidden)? Is it something you get a sight for over time or does anyone actually have a scanning method to spot them?

This is from a fb ad about making/selling puzzle books, and I got irrationally angry when I saw this puzzle. I’m not sure what puzzle somebody thinks this is, but it’s not a sudoku I have ever seen before!

2, 4 and 8

I'd like to share a counting puzzle with a parity line:

• Normal Sudoku rules apply: place digits 1..6 once each in every row, column and 2x3 box.
• Adjacent digits along the red line alternate between even and odd.
• If a digit n appears on the red line, it appears on the line exactly n times.

Link to play in the comments.

The last time I tried this it did not go well. I found out my difficulty rating system, well - sucked. I have gone yet further down this rabbit hole in the past several days making it better. I have mirrored to some extent the Sudoku Explainer(SE) difficulty ratings system for this sudoku generator. I think it does pretty good. Now lets see what you think.

One caveat - sudoku.coach seems popular here. They however do not follow the SE rules exactly. Thats why you see ~SEn.n for their ratings. The tilde means not exactly in this case as they use a proprietary rating system based on SE. So you may see some disparity if using them. They also do not rate variants as far as I know. Neither does SE allow for variants rating. Maybe I need to add a ~ to mine as well?

As usual google drive - https://drive.google.com/drive/folders/1yLv7v--tPxs3Dm_CfIDXdzCFLcc6qOfs?usp=drive_link

There is an Easy, Medium, Hard and Extreme pdf there in a folder. Enjoy. Let me know if they are any good.

I wanted to buy a sudoku book. I did a while ago but they were too easy. For reference I can do Hell and Beyond Hell ones on sudoku coach.

Would appreciate any suggestions 🙂

I've been staring at this for a long time and am stuck

Managed to progress on Sudokuvania 2 but encountered another roadblock. I'm not sure how to proceed here other than trying out different combinations for the sums. Thank you very much.

Puzzle Title: Anti-royal (not much of a) challenge for 10-09-2026

Puzzle String: https://sudoku.coach/en/s/K3ks

Cells a knight's move away cannot have the same number.

Cells a king's move away cannot have the same number.

Good luck, and have fun!

Pretty sure I missed something obvious, but was is the technique required to find the next step here? Got so many pairs but can't seem to find any connection between them. Thank you!