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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12
votes
1answer
997 views

Strategy for solving 0hh1 and Unruly?

Q42's game 0hh1 and Simon Tatham's game Unruly are two almost identical logical deduction games. In each one, we're given a square grid which is to be filled by tiles of two colours, and a certain ...
12
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1answer
245 views

News of the world

Here's a quick little puzzle to keep busy.
12
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2answers
755 views

(2 of 11: Moon-or-Sun) What is Pyramid Cult's Favorite Camera?

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 ...
12
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1answer
619 views

Stuck on a Nonogram puzzle

Help is needed. I have been stuck on this puzzle for some time. Any help or tips would be appreciated.
12
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2answers
273 views

Let's Play Tetris!

Fill the whole grid with Tetrominos. Every cell must be part of exactly one Tetromino. Tetrominos can be rotated as necessary. The colored clue cells must be part of the indicated type of ...
12
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1answer
403 views

Election Day is upon us!

Some election mayhem! Any puzzlers here or regulars excited? This is a picross or nonogram, for information about it and how to approach, please go here. Wanted to make my first short and easy ...
12
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3answers
654 views

Masyu puzzles with many circles

The rules of Masyu: Make a single loop with lines passing through the centers of cells, horizontally or vertically. The loop never crosses itself, branches off, or goes through the same cell twice. ...
12
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1answer
835 views

This new puzzle type needs a name {4}

I believe I have invented a new type of puzzle... What is its name? Begin by solving the 16x16 sudoku; each of the digits 1-16 must appear exactly once in each row, column and thick-bordered 4x4 ...
12
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2answers
539 views

Compoundoku wants 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) ...
12
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1answer
411 views

Is it Pajamas? Or Shampoo? Maybe a Cheetah? Oh I know, it's:

Title hint:
12
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1answer
632 views

Double feature: Braaains

This puzzle is part 1 of the Double feature series. The series will continue in "Double feature: Russian desman". Rules of Akari (also known as Light Up)1 Insert light bulbs into any ...
12
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1answer
221 views

Rhombicosidodecahedron Slitherlink

This is a Slitherlink puzzle, being played on the surface of a 3D object, a Rhombicosidodecahedron. If you are not familiar with Slitherlink puzzles, I don't suggest starting on this one. Rules in ...
12
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2answers
489 views

Slitherlink with crossing allowed

In a Slitherlink puzzle, you need to construct a single closed loop connecting points of a grid such that each number clue counts the number of adjacent loop segments. Normally, a Slitherlink puzzle ...
12
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1answer
500 views

Slitherlink - It's all in the 2s

Can you solve this Slitherlink puzzle that I came up with? And in CSV: 3 - 3 - 2 - - 2 - 2 - 2 - - 1 1 2 2 1 - - 2 - 2 2 - - - 2 - 1 2 - - 1 - I tried to ...
12
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1answer
403 views

Humans, vampires and mirrors

Here is a room composed of $10 \times 10$ squared cells. Some cells contain a double-faced mirror ( / or \ ) that reflects the light with an angle of $90°$ on both sides. The other cells can be empty (...
12
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1answer
271 views

Difference or addition on a rose petals

Arrange the numbers 1 to 20 onto the rose petals using these rules : Yellow petals contain odd numbers, white petals contain even numbers. The outer petals are the difference or addition of the inner ...
12
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1answer
155 views

Geisterbahn 2.0

This puzzle was inspired by the ruleset of Round 3 of the German Logic Masters 2019: Geisterbahn 2.0 Place the numbers 2 or 3 in some cells such that all the numbers are connected orthogonally, no ...
11
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3answers
540 views

How to solve this 0hn0 position?

What should be my next step in this game of 0hn0? I've managed to get this far, but none of the numbers are completed except the "1" in the top right, and there are so many possibilities for how each ...
11
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3answers
758 views

Puzzle needs a name

Inspired by @Stiv's This new puzzle type needs a name series, what is the name of the puzzle below? Start by solving the (quite tough) Nonogram, then apply some grid-deduction-deduction and discover ...
11
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3answers
877 views

Spell out your moves and reach the exit

You are a knight, far from your familiar checkered board. You have 9 moves to escape, but there are some rules. Each region must contain all letters matching the number move you are making. So, the ...
11
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2answers
743 views

(7 of 11: Fillomino) What is Pyramid Cult's Favorite Shape?

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 ...
11
votes
1answer
454 views

3D nonogram – What's in the box?

This is a three-dimensional nonogram. The first six squares depict the layers of a $6\times6\times6$ cube. The final square gives the enumerations for the Z-axis, top to bottom. Some rules: The grid ...
11
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1answer
1k views

Futoshiki Puzzle with the least amount of clue

You are supposed to create a new $5$x$5$ Futoshiki puzzle with the least amount of clues possible, but this puzzle needs a unique answer. In other words, What is the minimum number of clues for $5$...
11
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2answers
239 views

Heyacrazy: Careening

This is a Heyacrazy puzzle, designed at request of testsolvers of previous puzzles who wanted to see how longer diagonals would work. Rules of Heyacrazy: Shade some cells of the grid. Shaded cells ...
11
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1answer
635 views

3D nonogram – What's going on?

This is a three-dimensional nonogram. The first six squares depict the layers of a $6\times6\times6$ cube. The final square gives the enumerations for the Z-axis, top to bottom. Some rules: The grid ...
11
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3answers
616 views

Intersection Puzzle

I have invented a new puzzle called Intersection. Let's find out what it is! Intersection You are given an $n\times n$ grid with circles and boxes inside arbitrary squares. A circle cannot be in the ...
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1answer
2k views

Nested sudoku in entrance exam

My university set this question in 2013's entrance exam. Also the red boxes include from 1 to 9. What's the solution for this sudoku?
11
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1answer
730 views

Three-dimensional light bulbs

This is a three-dimensional Akari puzzle (also known as Light Up). The six squares represent the layers of a $6\times6\times6$ cube, top to bottom. The objective is to add light bulbs into any number ...
11
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1answer
481 views

An Incomplete Puzzle

I'm sorry to offload some of my work as the puzzle creator on to you solvers. (No, I'm not.) At least there's only one clue missing, right? EDIT: When the puzzle is ready to be solved, there will be ...
11
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1answer
297 views

Introducing: MIXXOX Grid Puzzle!

Rules of MIXXOX: Put either X or O in each empty cell. A border between two adjacent cells may have a mirror, denoted by a bold line. Some mirrors are already given. Note that the outer ...
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1answer
302 views

Nurikabe: Hindsight in 2020

This is a Nurikabe puzzle. The goal is to shade some cells so that the resulting grid satisfies the following rules.1 Numbered cells are unshaded. Unshaded cells are divided into regions, all of ...
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1answer
432 views

Nurikabe: Roaring twenties

This is a Nurikabe puzzle. The goal is to paint some cells black so that the resulting grid satisfies the following rules.1 Numbered cells are white. White cells are divided into regions, all of ...
11
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1answer
679 views

Double feature: Unpopular

This puzzle is part 9 of the Double feature series (first part here). The series will continue in "Double feature: Health shakes". Across 2. A victory is found in path leading to hardship (...
11
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1answer
442 views

Latin-Square Adjacent Puzzles

Here are two $5 \times 5$ Latin-Square Adjacent puzzles. For each cell, put a digit between $1$ and $5$ such that: Each row and column contains one occurrence of each digit $1$ to $5$. If two cells ...
11
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1answer
306 views

Masyu keep making those 3D puzzles?

This is a three-dimensional Masyu puzzle. The five squares depict the layers of a $5\times5\times5$ cube. The goal is to make a single loop in 3D space which fulfills the following properties: The ...
11
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2answers
371 views

Mosaic by Albrecht Dürer

This is a visual puzzle (known as "mosaic" or "fill-a-pix") with the same rules as MineSweeper: The grid is to be filled with colored and white tessera. Choose whatever color you like for the colored ...
11
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1answer
302 views

Brain-breaking 3D masyu

This is a three-dimensional masyu puzzle.1 The five squares depict the layers of a $5\times5\times5$ cube. The goal is to make a single loop in 3D space which fulfills the following properties: The ...
11
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1answer
595 views

Distance Puzzle

The rules are: 1. Draw two circles (O) in the empty cells in every row and column. 2. The numbers in the black cells indicate the space between the 2 circles in the black cells' row or column, in ...
11
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1answer
467 views

Twelve Labours - #07 Cleats 'N' Balls

This puzzle is part of the ‘Twelve Labours’ series, but can be solved independently. Previous instalments can be found here: Prologue | 01 | 02 | 03 | 04 | 05 | 06 Emerging from the barbers with a ...
11
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1answer
1k views

Sudoku with chess queen rules

This is a unique sudoku. With Rules : Common sudoku rules apply. Numbers 1,2,3 have an additional rule, they are also chess queens. If all others numbers removed, the 1s do not attack each other ...
11
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1answer
571 views

Oriental House: An original grid-deduction challenge

A different approach to an old concept of mine, Oriental House is a new grid-deduction puzzle based once again off exits and entries. The rules are as follows: Draw a path from S to F, passing ...
11
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1answer
281 views

Dividing up land

Historical records indicate that the brothers Geoff, Petro, and Olaf divided up their large rectangular estate between themselves. Unfortunately, evenly dividing up favorable landmarks resulted in the ...
10
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4answers
1k views

JonMark Perry's Grid Logic Puzzle

Consider the following puzzle type proposed by JonMark Perry. Start with a square grid of arrows, each one pointing in one of the four cardinal directions. For example: You start at the top left. ...
10
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3answers
692 views

Cipher text on an ancient wall

The following text was found written on the wall of an ancient tomb: $\text{DXFDMKEPU}$ Can you decipher what it means? Nearby the wall, this piece of parchment was found. Perhaps it is a clue ...
10
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3answers
701 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 ...
10
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2answers
889 views

Try to design a uniquely solvable masyu

Warning: extreme difficulty Does there exist a 6x6 masyu puzzle with one black pearl in each row/column (without any white pearls) which is uniquely solvable? What about for 7x7 grids? In fact, what ...
10
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3answers
987 views

A “Letter” Slope puzzle?

Your brother has been forcing you to some read some of his frankly ridiculous poetry, so, knowing that he was never a numbers man, you decide to vex him with a Number Slope puzzle. In fact, you are so ...
10
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2answers
496 views

Wumpus-hunting Masyu

You are an explorer looking to capitalize on a cave you've discovered. The goal is to construct a pathway that visitors can take safely. The problem is that the cave is full of dangers, including a ...
10
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1answer
249 views

How do I construct a Japanese-style “grid deduction” puzzle? [duplicate]

Logic puzzles like Nurikabe, Slitherlink, and Battleships -- the ones we call grid-deduction puzzles -- can be a lot of fun. How do I go about constructing them? What's the best strategy for making ...
10
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4answers
1k views

A new 4 x 4 arrow puzzle

Can anyone help me with solving this puzzle: Draw arrows in all fields around the diagram in a way that every arrow is pointing at least one number inside. The numbers inside the boxes equal the ...

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