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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. 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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9
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3answers
645 views

A Family Reunion

Names have been changed to preserve anonymity A group of 25 people, A to Y, arrived at Z's door to celebrate the family reunion. They each had something to show off. Z: I know you're all excited ...
9
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2answers
621 views

Yajilin minicubes: the Hullabaloo, the Brouhaha, the Bangarang

These are three-dimensional yajilin puzzles. In each puzzle, the four squares depict the layers of a $4\times4\times4$ cube. Shade some cells on each layer. The numbered cells show how many ...
9
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2answers
175 views

Heyacrazy: “LMI”

This is a Heyacrazy puzzle, originally constructed for a test for Logic Masters India. Rules of Heyacrazy: Shade some cells of the grid. Shaded cells cannot be orthogonally adjacent; unshaded ...
9
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1answer
215 views

A Difficult Rhombicosidodecahedron Slitherlink

This is the evil older brother of this puzzle. I'm posting it more out of scientific curiosity than because it is a fun puzzle, because it is not a fun puzzle. It's just really hard. I wrote a ...
9
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1answer
1k views

What is a “unique solution” in a Slitherlink puzzle?

In the question Five Slitherlinks, the querent suggests that "each [Slitherlink puzzle has] a complete solution". I'm newly reading about Slitherlinks, but I don't understand what makes a solution "...
9
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2answers
576 views

Haisu: Pixel Perfect

HAISU is a portmanteau of three Japanese words - 'hairu', to enter, 'su', number, and 'hausu', an English borrow word meaning house, of course. Together, we get a meaning of 'enter number house', ...
9
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2answers
449 views

Cryptic Crossword Sudoku

This puzzle is inspired by Matt’s excellent Cryptic Sucrosswordoku. Below is a sudoku as well as some cryptic clues. The clues lack enumeration and are in no particular order. The solutions to the ...
9
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2answers
315 views

Quick Tilepaint Puzzles: Corridors and Corners

Tilepaint (adapted from Nikoli) The areas enclosed by bold lines are called "Tiles" and color the tiles with the following rules. The cells of a tile must all be colored with black or left ...
9
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1answer
303 views

(6 of 11: Yajilin) What is Pyramid Cult's Favorite Places?

Dear PSE users and moderators, I’m new here in PSE, but I really need your help. There was this person who gave me a black envelope consisting 10+1 pages of puzzles, and also a scribble saying: “Find ...
9
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1answer
986 views

Logic 5x5 Letter Number Combination Grid

Hey I just thought other might enjoy the challenge of this puzzle as much as I did. Not the most easy thing to solve. Sort of like Sudoku, each row and column needs the letters A,B,C,D,E and each row ...
9
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1answer
334 views

Statue Park: Five

This is a Statue Park puzzle (originally constructed for the 2019 24-Hour Puzzle Championship, as part of a Tarot card themed set -- no prizes for guessing which rank this puzzle was). Rules of ...
9
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1answer
327 views

Double feature: Weightier

This puzzle is part 7 of the Double feature series (first part here). The series will continue in "Double feature: Going postal". Rules of Statue View1 Insert the four given pieces (<...
9
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2answers
769 views

How will you save Mike?

A direct hint: this question. Question starts from here: You are Dr. Nathaniel - a renowned archaeologist, and involved in a research about an ancient site. But, there is only one problem - the ...
9
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2answers
251 views

4 pieces into a big slitherlink

Arrange the 4 pieces into a big slitherlink. To help you arrange it, First find the solvable small slitherlink then put it in the bottom-left position. 1st piece 2nd piece 3rd piece 4th piece
9
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1answer
232 views

Vertical and Horizontal Bars - An Instructionless Puzzle

Study the 2 examples given on the left and solve the puzzle on the right! The solution for each puzzle can be uniquely determined.
9
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1answer
482 views

Ripple effects: A suite of puzzles and conundrums

Best explained here. Basically there are two rules: fill in each region with the numbers 1 to N, where N is the size of that region two numbers, both K, cannot both be in the same row or column if ...
9
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2answers
524 views

Tetromi-nuri-doku

Note: This puzzle was inspired by the one here, by Mike Q. Every square in the grid above, when the puzzle is complete, has a number between 1 and 9 in it and either is shaded or is not. Each 3x3 ...
9
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0answers
379 views

Grandma's keynote

Found this note which is addressed To my grandma, in her chest Since she's passed now, here's my quest.. What tickled her interest? And who invited her as guest?
8
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3answers
236 views

Quick Ripple Effect Puzzle: $70$ Empty Cells

Ripple Effect (taken from Nikoli) The areas divided by bold lines are called "rooms". Fill in all empty cells with numbers under the following rules. Each room contains consecutive numbers ...
8
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3answers
609 views

Getting all same side pairs

The goal is to get same side pairs of the 6 tiles, , to fit into a $2\times 3$ grid, so that all touching sides match like so (excluding the red part), for example:
8
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2answers
978 views

3D? No-no! 3 Sides

Introducing the Isometric Nonogram! α) "Boar"ing Definition [oink] Column: Blue Part + Green Cell Row: Yellow Part + Green Cell Adjacent/ Continuous cells: Purple Cell + any of the Orange ...
8
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2answers
222 views

You Sign Me Right Round

This is a 9x9 grid, with a sign in the center cell like shown. You can add signs to this grid one at a time following these rules: Each sign placed must point to the next sign placed Placed signs ...
8
votes
1answer
302 views

Backwards Boggle

I came up with a fun little 1-player puzzle for myself to do when bored. Pick 5-6 words, preferably words that share a good number of letters, and try to create a Boggle board containing all of those ...
8
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2answers
748 views

A spartan skeleton Sudoku

A skeleton crossword is a crossword where the black and white squares aren't given; you have to deduce them. Here's a generalisation of that idea to the Sudoku puzzle. Here's a 4 by 4 grid, with four ...
8
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2answers
289 views

Double feature: In concert

This puzzle is part 3 of the Double feature series (first part here). The series will continue in "Double feature: Hot stuff". Rules of Ripple Effect1 Fill the grid so that each cell ...
8
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2answers
293 views

Spiral Stumper Series: Instructionless Puzzle

Spiral Stumper Series is a $5$-puzzles series taken from the Final Round of a local (national) contest, KPK, which has been ended recently and authored by me. The theme is spiral and each puzzle is ...
8
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1answer
381 views

(5 of 11: Slitherlink) What is Pyramid Cult's Favorite Person?

Dear PSE users and moderators, I’m new here in PSE, but I really need your help. There was this person who gave me a black envelope consisting 10+1 pages of puzzles, and also a scribble saying: “Find ...
8
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2answers
288 views

Not Just Black and White

Answer for this puzzle is one word. Have fun! Highlighted parts are where I realised I have clued it wrong... Sorry for all this inconvenience! Hint: usefulness level 1 usefulness level 2 This ...
8
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2answers
328 views

Square Spin #4: Rude Awakening

Square Spin History: #1>#2>#3>#4 New Rule This puzzle introduces a new square type: Lonely squares (Ly) Lonely squares This type of square contains a box and it is ...
8
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4answers
434 views

A “Find the Path” Puzzle

I invented a puzzle, inspired by Simon Tatham's Portable Puzzle Collection. Is there anything that it could improve on? Was it too easy, or was it too hard? Anything I could add? What must I call it? ...
8
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1answer
249 views

Unusual Sudoku Puzzle

Find the solution to this Sudoku puzzle. The only problem is there aren't any normal Sudoku clues. Instead there are only some cryptic clues. What is the solution and how does the puzzle work? Edit: ...
8
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3answers
535 views

Ambiguous Grids

After six to eight weeks of waiting, your Shmikoli™ Ambiguous Grid Deduction Puzzle Set has finally arrived! You tear into the box only to discover that the instructions are missing. You shouldn't ...
8
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1answer
343 views

(10 of 11: Nurikabe) What is Pyramid Cult's Favorite Topic?

Dear PSE users and moderators, I’m new here in PSE, but I really need your help. There was this person who gave me a black envelope consisting 10+1 pages of puzzles, and also a scribble saying: “Find ...
8
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1answer
253 views

Grid puzzle solutions

I have a simple grid puzzle: Example: | X | Y | X | | Y | X | Y | | Y | X | Y | The move is defined as a row or a column move. So when you move one cell, ...
8
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2answers
369 views

Double feature: In cold blood

This puzzle is part 5 of the Double feature series (first part here). The series will continue in "Double feature: Legal trouble". Rules of Nurikabe1 Shade some cells in the grid. ...
8
votes
1answer
147 views

Nurikabe minicubes: the Headache, the Panache, the Apache

These are three-dimensional Nurikabe puzzles. In each case, the four squares represent the layers of a $4\times4\times4$ cube. The goal is to shade some cells in each layer so that the resulting space ...
8
votes
1answer
298 views

A Sincere Nurikabe Puzzle

So here's a standard Nurikabe puzzle. I'll be using the final (solved) grid for my upcoming local puzzle competition logo as it will spell the abbreviation of the competition name. So, what does it ...
8
votes
1answer
441 views

I'm Bad at Naming Things, so Just Try to Solve this Patterned Masyu Puzzle!

$\hskip1in$ The original Masyu rules apply. Make a single loop with lines passing through the centers of cells, horizontally or vertically. The loop never crosses itself, branches off, ...
8
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1answer
278 views

Puzzles: Meander

I have come up with an interesting type of puzzle based on the mathematical concept of a meander. The concept, of course, is not original to me, but the type of puzzle is, as far as I know. A ...
8
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2answers
1k views

Fill this 5x5 number grid incrementally, either by moving two boxes diagonally or moving three boxes in a row or column

One day, a friend has shown me a 5 by 5 grid, challenging me to fill it with numbers from 1 to 25. Obviously, it is not simple because there are some rules: The number 1 is placed in the center of ...
8
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3answers
473 views

Revenge of the Cryptic Crossword Sudoku

This puzzle is inspired by Matt’s excellent Cryptic Sucrosswordoku. Below is a sudoku as well as some cryptic clues. The clues lack enumeration and are in no relevant order. The solutions to the ...
8
votes
1answer
279 views

Mixed-breeds are puzzles too!

This is a three-dimensional mixed-breed puzzle. The five squares depict the five layers of a $5\times5\times5$ cube. The goal is to solve the odd-numbered layers as yajilin and even-numbered layers as ...
8
votes
1answer
182 views

Yajisan-Kazusan: Diagonal Arrows

This is a Yajisan-Kazusan puzzle. Rules of Yajisan-Kazusan: Several numbered arrows are given in the grid. Shade some cells so that: no two shaded cells are adjacent unshaded cells form ...
8
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4answers
493 views

The Knights and the Hounds

(With thanks and congratulations to Lee Leon) We rejoin our heroes several days after the events of The Knights' Gift, at the head of a pack of enormous staghounds, 1000 strong. Such a pack ...
8
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1answer
742 views

13-by-13 SIKAKU puzzle

A SIKAKU puzzle consists of a square or rectangular grid in which some of the cells contain a one or two digit number. To complete the puzzle, a Solver must divide the puzzle into a number of ...
8
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1answer
203 views

Restoring 3D Tetromino Puzzle

You won't believe this. I worked all night to make a new 3D tetromino puzzle, and just as I was about to save the final version there was a power outage! Now I can't remember what the final clues were ...
8
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1answer
754 views

Algebra Sudoku: Dozens

Alas, the grid deduction fortnightly is over, but my love for the genre remains the same - i.e. very high. So, here is another grid deduction puzzle. An algebra sudoku! I think the rules are fairly ...
8
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1answer
164 views

Heyacrazy: Forks

This is a Heyacrazy puzzle. Rules of Heyacrazy: Shade some cells of the grid. Shaded cells cannot be orthogonally adjacent; unshaded cells must be orthogonally connected. When the puzzle is ...
8
votes
1answer
184 views

4 More Meander Puzzles

My previous set of meander puzzles was fairly well-received, so I decided to make some more. If you didn't see the first set of meander puzzles, the instructions can be found here. Here they are: ...
8
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1answer
209 views

Double feature: Russian desman

This puzzle is part 2 of the Double feature series (first part here). The series will continue in "Double feature: In concert". Rules of Masyu1 Make a single loop which goes through ...