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.
942
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Regional Business
This is part 40 of the puzzle series Around the World in Many Days. Each part is solvable on its own.
Dear Puzzling,
The puzzle on the left-hand side is a regional Yajilin. Shade some cells in the ...
- 75.4k
9
votes
3
answers
1k
views
What kind of puzzle is this?
Hello, I found this puzzle in an old puzzle book, it's fun. Does anyone know if this kind of puzzle has a name, I want to find more, and maybe try making some. Thanks very much!
Here is the cover of ...
- 91
14
votes
2
answers
1k
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Very small regional Yajilin
This puzzle is part of the Monthly Topic Challenge #14: Think inside the (very small) box!.
Rules of regional Yajilin:
Shade some cells in the grid. Two shaded cells cannot share an edge, but can ...
- 75.4k
7
votes
1
answer
792
views
Before the Common Era
This is part 39 of the puzzle series Around the World in Many Days. Each part is solvable on its own.
Dear Puzzling,
The grid on the left-hand side is a KenKen puzzle. Fill the grid so that every row ...
- 75.4k
4
votes
1
answer
285
views
Nonogram with story
Fellow puzzlers, here's a nonogram I made for you. But it also has a story!
Two bored male casino dealers are waiting at the craps table. A very attractive blond woman arrives and bets $20,000 on a ...
- 159
6
votes
1
answer
215
views
Intermingled primes
This puzzle is part of the Monthly Topic Challenge #14: Think inside the (very small) box!.
6 different, 3 digit primes are stacked here in two layers.
You only see the sum of overlapping digits.
...
- 7,609
18
votes
3
answers
1k
views
Sums in a (very small) box
This puzzle is part of the Monthly Topic Challenge #14: Think inside the (very small) box!.
Place the digits 1 to 9 in the box below in such a way that in each row, each column and each diagonal, one ...
- 26.3k
-2
votes
1
answer
150
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What are the largest and smallest numbers in decimal base in this special Sudoku?
I have constructed the following hexadecimal 16×16 sudoku in this site:
The rules are like 9×9 sudoku tables (each number and letter should repeat only one time in each column, row, and 4×4 ...
- 109
12
votes
1
answer
544
views
Musk Oxen and Arctic Foxen
This is part 37 of the puzzle series Around the World in Many Days. Each part is solvable on its own.
Dear Puzzling,
This is an Aquarium puzzle. The grid is divided into “rooms”. Shade some cells in ...
- 75.4k
8
votes
1
answer
365
views
gambas al ajillo
This is a Tapa puzzle. That means you must shade some of the squares, so that:
No square containing text is shaded.
Numbers in a square indicate runs of consecutive shaded squares among the ≤eight ...
- 11.7k
15
votes
1
answer
324
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Slither-Yajilink: A match made in Hades
This puzzle is part of the Monthly Topic Challenge #13: Variety Slitherlinks.
This is a Slitherlink-Yajilin hybrid. Shade some cells in the grid and draw one non-crossing, non-branching line ...
- 75.4k
15
votes
1
answer
409
views
Seven similar 7x7 (pen-and-paper) logic puzzles
Oh no! I've just finished drafting some 7x7 logic puzzles, but I accidentally dropped all of them on the floor, and now they're all mixed up!
To make matters worse, I haven't gotten around to ...
- 958
7
votes
1
answer
302
views
A Watery Slitherlink
This puzzle is part of the Monthly Topic Challenge #13: Variety Slitherlinks.
A watermill is going to be built next to a cozy town. You are the designer of the aforementioned mill/slitherlink, and ...
- 2,450
14
votes
1
answer
679
views
Roughing It (Once More)
This is part 36 of the puzzle series Around the World in Many Days. Each part is solvable on its own.
Dear Puzzling,
The numbers in blue form a Tapa puzzle. Shade some cells in the grid so that the ...
- 75.4k
13
votes
1
answer
341
views
Nurikabe: Forties
The good news: It’s my birthday! The bad news: I’m 40 now. It’s not a great update. Just weaker stats with no cool new abilities. Anyway, here’s a Nurikabe to celebrate. Don’t worry, it should be good ...
- 75.4k
14
votes
1
answer
334
views
Double trouble - When slitherloops collide
This puzzle is part of the Monthly Topic Challenge #13: Variety Slitherlinks.
What happens when you're working on a couple of puzzles for the Monthly Topic Challenge and try to merge them?
Well, in ...
- 12.4k
3
votes
2
answers
282
views
Why were the Middle Ages called the Dark Ages?
You find yourself trapped in a room, with only one door to escape, and an important question to answer. You are standing on the tile marked with yellow:
How to get to the door is the main problem. ...
- 4,914
10
votes
1
answer
298
views
Walking a twisted path on a donut - a Möbius Slitherlink
This puzzle is part of the Monthly Topic Challenge #13: Variety Slitherlinks.
Have you ever wondered why there has to be an "inside" and an "outside" to every slitherlink loop?
...
- 12.4k
14
votes
1
answer
754
views
Slither-Numberlink: A monstrosity nature never intended
This puzzle is part of the Monthly Topic Challenge #13: Variety Slitherlinks.
Rules of hexagonal Slither-Numberlink:
Some numbers in the grid are slitherlink clues, some are numberlink clues. Zeroes ...
- 75.4k
14
votes
1
answer
487
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An X x X Slitherlink related to X
This puzzle is part of the Monthly Topic Challenge #13: Variety Slitherlinks.
The final answer is a six letter word.
Prefer no partial answers.
penpa
- 23.1k
4
votes
0
answers
212
views
Are infinite loops possible in the game Prodway?
I'd like to know if infinitely repeating sequences of moves (i.e. cycles) are possible in the following game:
Prodway is a game for two players (Black and White) that is
played on an initially empty ...
- 113
7
votes
2
answers
401
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Are infinite loops possible in the game Reneo?
I'd like to know if infinitely repeating sequences of moves (i.e. cycles) are possible in the following game:
Reneo is a game for two players (Black and White) that is played on an
initially empty ...
- 113
16
votes
1
answer
653
views
SlitherLITS: Don't colour outside the lines
This puzzle is part of the Monthly Topic Challenge #13: Variety Slitherlinks.
Adding a bit of colour to enhance the loopy goodness of a traditional Slitherlink.
Draw a single, non-intersecting loop ...
- 12.4k
5
votes
0
answers
204
views
Next Sudoku Number
Here is a sudoku puzzle coming from this magazine
I found that B5 and B6 can only contain 6 and 7. 8 cannot be in B5 because D1 would be a 8 and neither B3 not C1 could be a 8.
I thought it would help ...
- 173
17
votes
1
answer
947
views
An oddly coloured slitherlink
This puzzle is part of the Monthly Topic Challenge #13: Variety Slitherlinks.
I find something strangely satisfying about a well designed slitherlink puzzle, even one which is oddly coloured and ...
- 12.4k
12
votes
2
answers
1k
views
Slitherlink? I hardly know her!
This puzzle is part of the Monthly Topic Challenge #13: Variety Slitherlinks.
Rules of hexagonal Slitherlink:
Draw one continuous loop in the grid along dotted lines. The line cannot cross itself or ...
- 75.4k
22
votes
1
answer
960
views
The Metaslitherlink
This puzzle is part of the Monthly Topic Challenge #13: Variety Slitherlinks.
Below is a grid containing multiple small slitherlinks. These can be independently solved to form clues for the large ...
- 5,006
6
votes
1
answer
282
views
Is the Parity Sudoku solvable?
I have a new kind of grid puzzle (you could call it a variant of sudoku) I will be calling a Parity Sudoku.
Parity Sudoku is played on a 6x6 grid of integer cells with numbers ranging from 1 to 6. It ...
- 2,450
12
votes
1
answer
443
views
Sandwiches by the Seaside
This is part 31 of the puzzle series Around the World in Many Days. Each part is solvable on its own.
Dear Puzzling,
This is a sandwich sudoku puzzle. Each of the eight different letters in the grid ...
- 75.4k
4
votes
1
answer
181
views
Fill the circles with the numbers 4, 5, 6, ... 10
Using all the numbers 4, 5, 6, ... 10 exactly once, fill each empty circle with a number so that if two numbers are in circles that are joined by a line then their difference (in absolute value) is at ...
- 4,403
11
votes
1
answer
949
views
Make these 30 animals look cool
Place the following 30 animals in the grid:
Albatross Alpaca Anaconda Ara Bear Bison Chicken Dog Eagle Elephant Emu Hummingbird Ibex Ibis Impala Kangaroo Lark ...
- 4,914
11
votes
1
answer
438
views
Literally-Connecting Wall
This puzzle is a variant on the well-known connecting wall puzzles. May contain traces of grid deduction and happy stars 😊
Rules:
Your goal is to fill all the empty squares in the main grid (left) ...
- 7,240
31
votes
2
answers
8k
views
Is this Hashi puzzle unsolvable?
I found this puzzle in my dad's bathroom. The book is "Things To Do While You Poo On The Loo". I think the puzzle is malformed. Here is a Penpa link to an online solver. Is there actually an ...
- 504
12
votes
1
answer
377
views
Protected Schooling
This is part 26 of the puzzle series Around the World in Many Days. Each part is solvable on its own.
Dear Puzzling,
This is a Shakashaka puzzle. Mark some cells half-shaded along a diagonal (one ...
- 75.4k
0
votes
1
answer
185
views
Connect colored dots - puzzle
This is a puzzle of connecting all same color dots with each other so all the dots can be connected together and no box can be empty.
The connections shouldnt be crossed with each other
Below is the ...
- 19
7
votes
1
answer
371
views
Next logical move in Heyawake
I'm just starting out on Heyawake. On this puzzle, I didn't see the next logical move, so I tried the 3 box with LRL and then RLR and I didn't have any luck going down those bifurcations. What am I ...
- 71
5
votes
1
answer
255
views
How do I transcribe a KenKen into a Google Sheets?
Similar to this previous question, I have been slowly working through some PDF puzzle books. I will shortly come up on KenKen puzzles (called TomTom in the book, but the format is the same). Here is ...
- 10.1k
18
votes
1
answer
550
views
Tetromino Jigsaw Madness
This is part 23 of the puzzle series Around the World in Many Days. Each part is solvable on its own.
Dear Puzzling,
This puzzle is a crossword-jigsaw hybrid. Cover the white area of the grid with ...
- 75.4k
13
votes
1
answer
786
views
In It for the Long Haul
This is part 22 of the puzzle series Around the World in Many Days. Each part is solvable on its own.
Dear Puzzling,
The light grey numbers and arrows from a Yajilin puzzle. Shade some cells in the ...
- 75.4k
13
votes
1
answer
968
views
Sardines and Octopi
This is part 21 of the puzzle series Around the World in Many Days. Each part is solvable on its own.
Dear Puzzling,
The thick black lines in this grid form a LITS puzzle. Shade an orthogonally ...
- 75.4k
11
votes
2
answers
360
views
Orthogonally connecting even sudoku digits avoiding squares
Is there a way to complete a sudoku where you have to make sure all even digits are orthogonally connected to all the others, while avoiding 2x2 squares of even digits?
It is known to be possible when ...
- 113
10
votes
1
answer
666
views
Singles, Doubles, Triples
This is part 20 of the puzzle series Around the World in Many Days. Each part is solvable on its own.
Dear Puzzling,
The circled numbers in this grid form a Kurodoko puzzle. Shade some cells in the ...
- 75.4k
11
votes
1
answer
2k
views
Can experienced players tell when a Sudoku was randomly generated? Or if it's a shuffled version?
I'm trying to make a simple classic Sudoku game in JavaScript, and I'm wondering what considerations I should have in how experienced players might interpret the generated puzzles. I'm not very ...
- 321
2
votes
2
answers
157
views
Hard Sudoku: hint for next number
I tried a hard sudoku and I can't figure out what the next number is. I tried some online tools without any success (I don't want to have the final solution without any explanation).
I would be very ...
- 173
8
votes
1
answer
351
views
Layers upon Layers
This is part 19 of the puzzle series Around the World in Many Days. Each part is solvable on its own.
Dear Puzzling,
This time I have a Suraromu puzzle for you. The grid contains seven “gates”, ...
- 75.4k
10
votes
1
answer
332
views
Boulders in Valleys - Magnetic Confinement
This is a "Boulders in Valleys" puzzle - it's been posted a few times on this site. This specific puzzle's solution has an interesting property that made it quite hard to design. The ...
- 681
14
votes
1
answer
807
views
Sneaks and Addlers
This is part 18 of the puzzle series Around the World in Many Days. Each part is solvable on its own.
Deаr Puzzling,
This is an I Have No Idea What I’m Doing crossword. The clues are a mix of 10 ...
- 75.4k
1
vote
1
answer
159
views
Explanation why next cell has to be a certain value
I'm an absolute beginner and was stuck at the first puzzle of Sven's Sudoku Pad. I reached the following board state, where I noted for every cell which values were possible:
After a while I simply ...
- 13
9
votes
1
answer
801
views
Paranormal Activity
This is part 15 of the puzzle series Around the World in Many Days. Each part is solvable on its own.
Deаr Puzzling,
The numbers in blue here form a Nurikabe puzzle. Shade some cells in the grid so ...
- 75.4k
10
votes
1
answer
443
views
Coasting Along the Coast
This is part 14 of the puzzle series Around the World in Many Days. Each part is solvable on its own.
Deаr Puzzling,
The larger grid is a Fillomino puzzle. Each of the six different letters in the ...
- 75.4k