Questions tagged [grid-deduction]

Puzzles such as Sudoku or Kakuro, where the final state of a pre-existing grid must be deduced logically through clues placed within and/or around the grid. Use with the [logical-deduction] tag. For puzzles where you are given a list of clues which can be used to compose a grid to solve them logically, use the [logic-grid] tag instead.

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7
votes
1answer
55 views

The Nurikabe of Peace

Today is the 75th anniversary of Sir Winston Churchill's speech "The Sinews of Peace" which introduced to the world the phrase "The Iron Curtain". This puzzle is inspired by that ...
8
votes
2answers
176 views

Double sudoku - two-digit numbers, the 1s and 10s places both form Sudokus [closed]

Using distinct 2-digit numbers from 11-99 that have no zeros, fill in the grid so that the tens digits form a Sudoku and the units digits form a (different) Sudoku. There might be a mathematical way ...
19
votes
1answer
307 views

Escape from Sudoku!

An entry in Fortnightly Topic Challenge #50: Escape Rooms I hesitated to enter this in the Escape Room FTC, but I definitely was inspired by the challenge to create this puzzle, and it is, in some ...
7
votes
0answers
165 views

The Puzzling Free-to-Play Escape Room, naturally!

An entry in Fortnightly Topic Challenge #50: Escape Rooms Without revealing too much, knowledge of geek culture and/or superb Google skills are required for this puzzle. Coming from an anime ...
1
vote
4answers
135 views

I need some help with this 15x15 nonogram

I have been working on this nonogram for some time and can't seen to figure out what to do next... This is the link: https://nonograms-katana.com/play/#game
8
votes
1answer
191 views

Nurikabe: The Terrible Tower of Threes!

This puzzle is a quick and fun little Nurikabe that is very tall, because I am not. It's not particularly tough, but if you need a nice relaxing grid-deduction puzzle to calm your brain today, this ...
0
votes
0answers
116 views

7x7 Skyscraper with clues and prefilled skyscrapers - next steps? [closed]

It's me again. I have another skyscraper issue. My program is now able to solve all the skyscrapers with sizes up to 8x8 and beyond. The only time it cannot calculate the complete solution is with 7x7 ...
1
vote
1answer
109 views

Number crossword puzzle

I'm trying to solve the following quiz from my daily quiz calendar (I have it in paper so I cannot give a link). It's like a crossword puzzle but with numbers. The empty cells should be filled with ...
6
votes
1answer
178 views

Fillomino with Sums: The Fillo That Smiles Back!

This puzzle is a Fillomino, with the special variant rule of Sums ("Cages") being applied. You might also notice that this particular fillomino is giving you a smile! This is my first time ...
8
votes
1answer
356 views

Trivia… sudoku

An entry in Fortnightly Topic Challenge #49: Pub Quiz Camouflage Please do not search the answers online (hence the no-computers tag), otherwise it would be too simple to solve this puzzle. I tried ...
5
votes
1answer
187 views

Double Ducky (or Fu-two-shiki)

There are two* logical, discrete ways to solve this Futoshiki puzzle, each with its own unique solution. You can solve it using the letters given, or use the numbers 1-5, but if you map the letters to ...
0
votes
1answer
94 views

Skyscraper 6x6 - unable to get next step

I tried to write a program to solve a Skyscrapers puzzle. Currently I'm teaching it to find the next steps out of nopes (values which cannot be present on the field) values and clues. So far the field ...
9
votes
1answer
162 views

Scrabblescrapers

An entry in Fortnightly Topic Challenge #48: Unusual tag mix In this puzzle, you are given a 5x5 grid that you need to populate with a word square, so that the rows and columns form words (as defined ...
14
votes
2answers
591 views

Now you're Packing with Portals #2: Hashtag

Place the colored shapes into the white area, without rotations or reflections, so that they fill it perfectly. The gray walls don't just block shapes, though - they act as portals! When you place a ...
7
votes
1answer
149 views

Nurikabe: Five Below

This puzzle is another one of my Nurikabes, and this time it's a smaller one made entirely of pieces that are 5 or less. Perhaps you can tell that making puzzles in this genre is slowly becoming my ...
5
votes
1answer
445 views

Skyscrapers 6x6 - Stuck at the end

I tried to write a program to solve a Skyscrapers puzzle. Until the last steps I always used the opposite clues. But I can't find a solution for the last cells. This is where I am: ...
42
votes
2answers
2k views

Now You're Packing with Portals #1

I was staring at my window last night, and daydreaming (nightdreaming?) about filling it with shapes. Suddenly, I was struck with inspiration for a new type of puzzle! Here's a fairly easy instance: ...
14
votes
1answer
445 views

Pento-Doku: Pentominous + Sudoku

Intended for Fortnightly Topic Challenge #47: Wacky Sudokus, but I was too slow making it... not for lack of trying, I assure you This puzzle is both* a Pentominous and a Sudoku**. Rules Solve the ...
3
votes
1answer
87 views

A Final Digitial Sudoku! - SS#14

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to the final puzzle in this series! For more information about the series, see the first ...
12
votes
2answers
566 views

Unequal Curfew - Donut Hole

This is a Curfew variant. Curfew is a genre invented by Hempuli; I made a slight modification to give this variant. Rules of Unequal Curfew: Draw a loop that visits every circle. Each visit to a room ...
15
votes
1answer
436 views

This Sudoku Park iS LIT!

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" The grid below is a normal Sudoku grid with normal Sudoku clues, but the completed grid also houses a Statue Park! The completed ...
12
votes
1answer
290 views

Sudoku: Odd Bonds

An entry in Fortnightly Topic Challenge #47: Wacky Sudokus. Edit: Clarified three of the rules. Rules: Normal sudoku rules apply. Inside the sudoku, there exists one "loop". The loop ...
9
votes
1answer
234 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
456 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 ...
20
votes
1answer
957 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 ...
15
votes
2answers
2k views

Hotaru Beam Puzzle: Is it impossible?

I saw this puzzle on Twitter by user @lilva_0419 and I personally feel that it is impossible to solve. Can you prove me wrong (or right)? Source on Twitter Try it online Rules (see Wikipedia): ...
7
votes
1answer
102 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
401 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 ...
26
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
306 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 ...
10
votes
1answer
368 views

Nurikabe: The Super-Kabe Attacks!

This puzzle is another Nurikabe, but with a new twist for me: it's a gigantic Super-Kabe! It's also, in my opinion, quite tricky and has some interesting deductions. I hope you enjoy! Rules of a ...
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
476 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
242 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
286 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 ...
7
votes
2answers
655 views

Are there any games like 0hh1 but with bigger grids?

I am loving 0hh1 but I got bored by the largest grid 12x12. Are there similar games but with much larger grids?
18
votes
1answer
269 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. ...
10
votes
1answer
318 views

Nurikabe: The Twisty Corridors

This puzzle is a Nurikabe. It is a little tougher than my previous one, which was designed for newer solvers, and it has a particularly squiggly solution that I found pleasing enough to post - hence ...
7
votes
1answer
167 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 ...
15
votes
1answer
925 views

Stop BorgBot before it's too late!

There was a deafening metallic thunk as the rogue AI locked the door of the PuzzlingCorp server room, trapping the engineers inside. A countdown appeared on the computer screen... and began counting ...
3
votes
1answer
125 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
218 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 ...
11
votes
1answer
174 views

Greener Grasses: Nusi's Birthday

Here is another Greener Grasses puzzle. Also, happy happy birthday to my fellow Indonesian puzzler, Nusi! I'm sorry that I realize the puzzle was broken in the last-minute checking so a single letter ...
9
votes
1answer
156 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
383 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 ...
21
votes
1answer
481 views

Stupendous Sponge

General Notes This puzzle takes the form a 9×9×9 level-one Menger sponge whose surface is divided into 648 1×1 cells. The aim is to draw a single non-crossing loop along its surface by connecting the ...
14
votes
1answer
583 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 ...
-4
votes
2answers
1k views

My sister has gone Puzzled again

I once got a letter from my younger sister. It reads :- Hello brother, How are you? I am fine. I have seen you have given me a lot of gifts, thank you for that. Here's a present from my side. Since I ...
20
votes
1answer
537 views

2021 Unpainted Masyu

Paint some white circles to black such that the Masyu will be uniquely solvable and: Exactly 2 of 11 white circles on the left forming '2' should be painted black. Exactly 0 of 12 white circles on ...

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