Questions tagged [sudoku]

A Sudoku is a puzzle consisting of a grid to be filled with symbols, such that each constraining unit contains each symbol exactly once. The typical example is a 9x9 square to be filled with the numbers 1 to 9, where the constraining units are rows, columns, and 3x3 blocks.

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9
votes
1answer
118 views

A Fractal Sudoku - SS#13

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to the penultimate puzzle in this series! For more information about the series, see the ...
9
votes
1answer
410 views

Sudoku with no grid and no numbers!!? - SS#12

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to the twelfth puzzle in this series! For more information about the series, see the first ...
19
votes
1answer
865 views

Sudoku in Technicolor!

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" This puzzle consists of three overlapping Sudokus, coloured red, blue and green, so each cell will contain three digits, one of ...
0
votes
1answer
90 views

10X10 Sudoku with a specific requirement

Let's have a 10x10 grid. We want to create a Sudoku in which, in each row, the pairs (a+b), (c+d), (e+f), (g+h), (i+j) add to one of the following numbers: 7, 9, 11, 13, or 15. Can you construct a ...
7
votes
1answer
84 views

This Sudoku takes a step up! - SS#11

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to the eleventh puzzle in this series! For more information about the series, see the first ...
37
votes
1answer
1k views

Didn't you ask me for a crossword?

An entry in Fortnightly Topic Challenge #forty-seven: "Wacky Sudokus" Here's that crossword you asked for... Sorry, what's that - you didn't ask me for a crossword?? TASK: Solve the puzzle ...
12
votes
1answer
312 views

Skyscrapers in Sudoku!!! - SS#10

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to the tenth puzzle in this series! For more information about the series, see the first ...
23
votes
1answer
1k views

A Puzzling Sudoku (Warning: Hot!)

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" A Sudoku with an oddly familiar shape. Here's a Penpa Link. Rules: Normal Sudoku rules apply (Special) Thermometers: The ...
9
votes
1answer
280 views

A 7x7 Suguru - SS#9

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to the ninth puzzle in this series! For more information about the series, see the first ...
25
votes
1answer
1k views

The Blank Sudoku

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" (h/t to Beastly Gerbil, whose 1,2,3... Trinary!!! puzzle provided inspiration for this puzzle) This puzzle is a normal Sudoku, ...
11
votes
1answer
448 views

A Difficult Wacky Sudoku - SS#8

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to the eighth puzzle in this series! For more information about the series, see the first ...
12
votes
1answer
220 views

A Scrumptious Sudoku Sandwich - SS#7

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to the seventh puzzle in this series! For more information about the series, see the first ...
11
votes
1answer
266 views

Sudoku… with 10 digits? SS#6

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to the sixth puzzle in this series! For more information about the series, see the first ...
17
votes
1answer
234 views

Compoundoku wants REALLY BIG and WACKY!

This is an entry for Fortnightly Topic Challenge #47: Wacky Sudokus. Rules of Compoundoku: Solve both left and right Sudokus. In addition, the board below them is the Compound Board of both Sudokus. ...
7
votes
1answer
141 views

A Mosaic Sudoku - SS#5

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to the fifth puzzle in this series! For more information about the series, see the first ...
3
votes
1answer
104 views

Sudoku + Nurikabe = Sudokabe

The following Sudoku has a nice little twist: after solving, use the numbers in the green squares as a basis for a Nurikabe puzzle. You can create a new grid for the Nurikabe (a 9x9 grid with the ...
14
votes
1answer
196 views

This is an Odd Sudoku - SS#4

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to the fourth puzzle in this series! For more information about the series, see the first ...
8
votes
1answer
136 views

Shattered Webs - SS#3

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to the third puzzle in this series! For more information about the series, see the first ...
10
votes
2answers
364 views

1, 2, 3… Trinary!!! (SS#2)

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to the second puzzle in this suduko series! For more information about the series, see the ...
14
votes
1answer
543 views

The Blind Killer - a new series! SS#1

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to a new sudoku series! This series will run for the duration of the current Fortnightly ...
12
votes
1answer
733 views

If 2020 Were A Sudoku

A bit of light relief to round out the year. No special genius required :-)
12
votes
2answers
297 views

A sudoku that's already filled in for you

The usual rules of sudoku apply: each row and column must have one of each digit; plus, if you divide the whole nine-by-nine grid into nine three-by-three subgrids, then each subgrid has one of each ...
14
votes
1answer
363 views

Sudoku - less than 6 and knight's move

In the following sudoku, the numbers on the outside indicate the first number less than 6 seen in that row/column. In addition, a number in the sudoku cannot be a knight's move from an identical ...
7
votes
1answer
180 views

The First No L Sudoku

Normal Sudoku rules apply. In addition no L-shaped tetromino can contain four consecutive digits (for instance you can't have r2c9=5,r4c9=8). The little killer clue indicates cells on the indicated ...
11
votes
1answer
268 views

Less than 6 Sudoku

In the following sudoku the numbers on the borders indicate the first number less than 6 seen in that row/column. So for example, the 4 at the bottom means that the first number less than 6 seen from ...
5
votes
1answer
109 views

Sjudoku II - A greater challenge in the world where 9 is 7

This is more difficult instance of a puzzle posted here. Rules similar to Sudoku applies: In each disk, the numbers 1,2,...7 should appear exactly once. No line may contain duplicate digits (note ...
20
votes
2answers
329 views

Tackling The Triptych

Normal Sudoku rules apply. Numbers on thermometers must increase, starting from the bulb end. Killer clues indicate the sum of three digits in a cage, which cannot include repeated digits. In columns ...
36
votes
4answers
2k views

Sjudoku - in a world where 9 is replaced by 7

Sjudoku (sju = seven in Swedish). Rules similar to Sudoku applies: In each disk, the numbers 1,2,...7 should appear exactly once. No line may contain duplicate digits (note that there are lines in 3 ...
11
votes
2answers
548 views

An experimental sudoku

(Here is an experimental Sudoku created by me, however, the "box" constraint is not originally mine, but it'd be fun to try out this constraint.) Rules: Normal Sudoku rules apply. ...
24
votes
3answers
2k views

Ever heard of a W-Sudoku?

You may have heard of a type of Sudoku called an XV-Sudoku. In such a Sudoku, cells connected with an "X" must sum to 10 and cells connected with a "V" must sum to 5. In this W-...
5
votes
1answer
210 views

Sudoku Logic From Another Planet

This is the brutally hard Tatooine Sunset Sudoku puzzle by Philip Newman ... except the Noble Happy Star has goofed! Two of the digits have been swapped and there are multiple solutions. Fortunately, ...
2
votes
1answer
231 views

Suko-kulink (Sudoku, Suko and Slitherlink tri-brid)

Rules: The lower part of the puzzle is a sudoku. Basic sudoku rules applied. The upper and right of the puzzle are suko puzzles. The numbers in circle and to the selected square has the same number ...
6
votes
1answer
108 views

Sudokus everywhere 2

Every 9x9 box is a valid sudoku, making 4 sudokus in all. Hopefully this one is a little more challenging than the previous one. I tried keeping the clues symmetric, but didn't quite manage. Enjoy!
18
votes
1answer
779 views

Sudokus everywhere!

Every 9x9 box is a valid sudoku, making 9 sudokus in all. I'm not sure how hard it is as I started solving it with just a few clues, then added more whenever I got stuck. Enjoy!
7
votes
1answer
958 views

A sudoku with only four given digits and some more rules

Ok so this is one of the hardest sudokus (and one of the best sudoku) I have ever seen, with only $4$ given digits. There are some more rules too :- $(i)$ First, normal sudoku rules apply here. $(ii)$ ...
12
votes
1answer
487 views

An odd looking Sudoku

Somewhat in the spirit of Stiv's This new puzzle type needs a name, can you solve this odd looking Sudoku and give it a name?
8
votes
1answer
281 views

Hero Wars RPG - The Sudoku!

In the popular online action RPG game Hero Wars, the player has to solve some simple but fun puzzles to win loot such as weapons and cash – assuming the incessant ads I’ve seen on Facebook are all ...
1
vote
0answers
139 views

Are there Sudokus that are so hard that no known logical deduction techniques can reduce it? [duplicate]

Are there Sudokus that are so hard that no known logical deduction techniques can reduce it? Maybe such a technique would reduce away multiple options?
3
votes
1answer
216 views

Will forcing chains break this sudoku puzzle?

I am trying to pick up advanced sudoku techniques by practicing with “difficult” puzzles as suggested by my sudoku app. In this puzzle, I am stuck in the position as shown below. I think I can make ...
1
vote
0answers
50 views

Is there a sudoku app where the hint identifies the squares/logic to use to solve the next step?

I have an app that has different levels of sudoku puzzles and I'm trying to learn to solve Expert. The app I'm using has a hint function, but all it does is fill in the correct answer in a selected ...
10
votes
1answer
300 views

No Numbers Sudoku: The Ball of Queens

Those are all of the numbers you need. No, I did not forget any. Normal sudoku rules apply. All numbers, except for 1's and 9's, are queens with respect to themselves. E.g. 2's have the queen's ...
9
votes
1answer
555 views

How to see why single candidates are obviously correct?

I am trying to understand something that should be simple. I have a "easy" puzzle here, and immediately found where 8 should be in the middle box. But in various Sudoku Apps, they show &...
17
votes
1answer
374 views

How to Trap Your Moderator

You have locked your least favorite moderator behind a 27x27 Sudoku... Now you regret, but you have forgotten how to solve the puzzle... CSV version: ...
4
votes
1answer
346 views

Does “naked set” method always solve a sudoku?

Is always possible to solve a sudoku (that has a unique solution) using only naked pair/triple/quad methods? If not, what about using naked set and hidden set methods combined togheter? I need to know ...
-1
votes
2answers
443 views

Tribute to a Great Mind

This is a puzzle based on an existing Sudoku problem composed by someone else. There are nine regions and each row/column/region must contain the same set of nine different letters: {G, R, E, A, T, M,...
2
votes
1answer
132 views

A slightly different type of Sudoku puzzle

The following image shows two valid Sudokus. The first was copied verbatim off Wikipedia, and the second was obtained by rotating 90 degrees. Any two distinct valid Sudokus must differ in at least ...
20
votes
2answers
1k views

Sudoku in the third dimension (3D Sudoku)

People seemed to enjoy my last Sudoku variant puzzle - Samurai Pseudoku, so I spent this week making another! This one is going to require using logic you've never used before... The last one was a ...
15
votes
1answer
287 views

Compoundoku wants REALLY BIG!

Rules of Compoundoku: Solve both left and right Sudokus. In addition, the board below them is the Compound Board of both Sudokus. Each number on the Compound Board should tell either: (1) the number ...
9
votes
4answers
498 views

The Existence of Total False Sudoku

Is it possible to construct a valid 9x9 puzzle of Total False Sudoku? Total False Sudoku is a regular Sudoku puzzle where all given clue numbers are wrong. A valid puzzle is a puzzle that has only a ...
60
votes
2answers
3k views

Sudoku like you've never seen it before

I've spent this week trying to create a difficult logic puzzle which is a combination of two Sudoku varaints, 'Samuari Sudokus' and 'Pseudokus', and this combo is unlike anything you can find online. ...

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