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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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### Hexagonal Kurokuron

Kurokuron (クロクロ一ン: "black clone"), is a shading puzzle that first appeared in Puzzle Communication Nikoli issues 153-155. Identical rules apply to a hexagonal grid. Rules Shade some cells such that: ...
548 views

### Double n-queen puzzle, with sudoku rules

Put 9 blue queens and 9 pink queens, with rules : If the blue queens removed, each pink queens do not attack each other. If the pink queens removed, each blue queens do not attack each other. Each 3×...
2k views

### Move the coin in the color grid

You need to move the Coin from the S(tart) cell to the END cell. Rules: From S you can move to cells 2,7 or 8. From BLUE cells you can only move ONE space diagonally. From YELLOW cells you can only ...
691 views

### 3D Crossword, Cryptic, Statue View & Maze

The following image depicts the layers of a $5\times5\times5$ cube. Using 3-dimensional thinking, can you find the way out of the cube? Empty version with no crossword numbers Empty version ...
598 views

This puzzle is a combination between a Slitherlink and a Fillomino. You should put a number in each square and draw a single closed loop over the grid such that the following properties are satisfied:...
841 views

### The Peculiar File

So I was browsing through my computer files earlier and I found a file I'd not seen before. I was wondering if you guys could help me figure out what it's about. This is where I found it: This is ...
503 views

### Quick Kurodoko Puzzle: Threes and Triples

Kurodoko (taken from Nikoli) Colour cells black according to the following rules. The numbers on the board show the number of white cells from the number to the nearest black cell or to the ...
794 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 ...
709 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 ...
377 views

### The Terrible Twos of Slitherlink

This question is aimed at people who have a really good grasp of standard Slitherlink puzzles. This is a standard, square cell, 10x10 Slitherlink puzzle I designed. It isn't what I would call a "...
511 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 ...
404 views

Title hint:
387 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 ...
445 views

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 ...
306 views

### Sandwich Sudoku: First 12 digits of pi

Sandwich Sudoku, or "Between 1 and 9 Sudoku", is a variant of Sudoku. A YouTube channel introduced this variation. Rules: Standard Sudoku rules. Place numbers from 1 to 9 in every row, column, ...
260 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 ...
487 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 ...
850 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 ...
729 views

### Twelve Labours - #02 Lernaean Hydration

This puzzle is part of the ‘Twelve Labours’ series. Previous instalments can be found here: Prologue | 01 His first labour now complete, Hercules made his way up the street to the storage depot for ...
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 $5$...
525 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 ...
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?
454 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 ...
690 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 ...
238 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: ...
250 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 ...
182 views

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 ...
559 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 ...
249 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 ...
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 ...
840 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 ...
933 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 ...
483 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 ...
706 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 ...
801 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 ...
328 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 ...
737 views

### (3 of 11: Akari) What is Pyramid Cult's Favorite Car?

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 ...
481 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 ...
206 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 ...
487 views

### (8 of 11: Ripple Effect) What is Pyramid Cult's Favorite Skill?

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 ...
415 views

Fictional story: As everybody knows I'm not good at making puzzles so I ordered a Build-your-own™ Dominosa kit! This should be good for my Dominosa building skills, I thought to myself. And today, ...
469 views

### 5x5 Grid with all two digit numbers

There is a $5\times5$ grid where you are supposed to put all two digit numbers which consist only of the digits $1$ to $5$, namely $11,12,13,14,15$,$21,22$,.... The task is to put all these two digit ...
297 views

### Volcanic 3D masyu

This is a three-dimensional masyu puzzle. The six squares depict the layers of a $6\times6\times6$ cube. The goal is to make a single loop in 3D space which fulfills the following properties: The ...
199 views

### Lazy puzzler's masyu

The creator of this masyu forgot to add the final stone, so the puzzle remains incomplete. Finish his job for him by placing one additional stone (either black or white) on the board so that the ...
303 views

### Double feature: Legal trouble

This puzzle is part 6 of the Double feature series (first part here). The series will continue in "Double feature: Weightier". Rules of Hitori1 Shade some cells in the grid. No ...
224 views

### Non-Congruent Fillomino

Here's a Fillomino puzzle (rules can be found here). The gimmick is that no two areas can be congruent. Enjoy!
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 ...
523 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 ...