# 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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461 views

### Hey! Wake Up! Look At This Grid Puzzle!

The grid is divided into rooms, though some are wibbly-wobbly weird-shaped. Hey, aren't these normally supposed to be blocks? What should the title of this puzzle really be? ...
654 views

### Partiti : solve this new type of puzzle

These are puzzles similar to Kakuro, which is the creation of a friend of mine whom I met last year: Rules: Place one or more digits from 1 to 9 in arbitrary order in each empty cell, such that a ...
633 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×...
459 views

### Sudoku - less than 6 and knight's move

In the following sudoku, the numbers on the outside indicate the first number less than 6 seen in that row/column. In addition, a number in the sudoku cannot be a knight's move from an identical ...
296 views

### Tapa on a Penrose Tiling

An entry in Fortnightly Topic Challenge #51: Non-rectangular grids. This is a standard Tapa puzzle, on a non-standard Tapa grid...the "grid" is a Penrose tiling! Since the grid is not ...
203 views

### Domatic lights - 4 colors

You must add red, green, blue and yellow light bulbs to the grid to satisfy these rules. Each white hex must contain either a red, green, blue or yellow light bulb. Light bulbs of the same color ...
1k views

### Yin-Yang: All-White

Here is a standard Yin-Yang puzzle. Rules of Yin-Yang: Fill each empty cell with either a black circle or a white circle. All white circles should be orthogonally connected, so do all black circles. ...
563 views

### Jewel Cave - A Statue Park-Cave Hybrid

The goal of this puzzle, a hybrid of Statue Park and Cave, is to place the given shapes into the grid, subject to the following rules. As in both original puzzles, all unshaded squares must form a ...
411 views

### The entrapment of Beastly Gerbil

Part 1: The disappearance of Beastly Gerbil Part 3: The escape of Beastly Gerbil I've been trapped here for what feels like forever. This is all I've known. Darkness. The occasional flash of light, ...
510 views

### Slitherlink - A0, B1, C2, D3

The standard Slitherlink rules apply. However, first replace $A_1$, $A_2$, $B_1$, $B_2$, $C_1$, $C_2$, $D_1$, and $D_2$; such that the Slitherlink is uniquely solvable. Moreover, these equations must ...
1k 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 ...
396 views

### Piece de Resistance - Jack in all Tags… But Master in All?

Jack in all Tags... But Master in All? This puzzle is part of the "Piece de Resistance" series. Go back to Part 1 (Ace) for the story.Ace Two Three Four Five Six Seven Eight Nine Ten Queen King... ...
303 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 ...
741 views

### A bicolour masyu

This is a bicolour masyu puzzle. Instead of making one continuous loop, the goal is to make two separate loops, one blue and one red. The coloured circles must be used for the loop of the same colour, ...
577 views

### A spiral Ripple Effect puzzle

I'd say the rules to a ripple effect puzzle are best explained here. Anyways, I was making a bunch of Ripple Effects and decided to do a big one which didn't work out as I'd hoped, in that I needed ...
830 views

### Tatamibari: an introduction

This is an entry for Fortnightly Topic Challenge #44: Introduce a new grid deduction genre to the community This is a Tatamibari puzzle, where you divide the grid into rectangles and squares. Rules ...
506 views

### Heteromino: Introduction

Heteromino is an area-dividing puzzle with very simple rules. I encountered this puzzle type on puzz.link, and seeing there's none posted here, I decided to give it a try. Here is an example puzzle ...
431 views

### Hetero-F(our|ive)-Cells

This is a hybrid of Four Cells and Five Cells (uses pentominoes instead of tetrominoes), with a global no-repeated-piece rule. Rules: The grid is to be divided along the grid lines into areas ...
877 views

### A walk after dark

This is a Palisade (or n-Cells) puzzle. The rules are: Thicken some of the squares' sides so the thick borders outline cells. One such cell comprises just one square; one cell comprises precisely two ...
404 views

### Hexagonal Nurikabe

Nurikabe is a popular grid puzzle, usually played on a square grid. Here is my attempt to adapt it to a hexagonal grid. To solve it, you must shade cells in the grid such that these conditions are met:...
258 views

Both Masyu and Slitherlink puzzles have as their target a single closed loop that does not touch or intersect itself. So it seems natural to create a hybrid that uses both Masyu and Slitherlink clues. ...
660 views

### Tetromino minesweeper: the Amphitheater

This is a minesweeper puzzle with a tetromino twist. The goal is to place mines in the grid, following a few constraints. Rules: A number indicates how many adjacent (including diagonally adjacent) ...
457 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 ...
388 views

### Colombian Sudoku

Fill each empty cell of the board on the left with a digit between 1 and 6. Each column and row must contain all digits. The dots outside the board on the right indicate how many cells in the ...
518 views

### On The Subject of X-Rays

(This is part of a series of puzzles written for Timwi for a Secret Santa puzzle exchange, themed around various custom modules for the game Keep Talking and Nobody Explodes. No KTaNE knowledge is ...
296 views

### Fighting Fish: An Aquarium-Star Battle Hybrid

This is an entry for Fortnightly Topic Challenge #44: Introduce a new grid deduction genre to the community. UPDATE NOTE: The original image had the upper right indicator that there are two fish per ...
764 views

### A true no-no-gram

This is a nonogram with the usual rules. That is, you must fill white squares in with black so that the numbers at the head of each row or column indicate, in order, the respective lengths of ...
624 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, ...
298 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 ...
447 views

### Windmill: A Masyu Puzzle

The standard Masyu rules apply.
368 views

### Greener Grasses: Around the Trees

This is an entry for Fortnightly Topic Challenge #44: Introduce a new grid deduction genre to the community. Greener Grasses is apparently a new genre of grid puzzle. Pitched by Joseph Howard and ...
297 views

### Nurikabe: A Gentle Walk in the Hall of Giants

This puzzle is a Nurikabe that is designed to be a gentle introduction to the genre, with a learning curve of progressively harder deductions. It is encouraged for first-time solvers and those who ...
294 views

### Unpainted Masyu

Exactly 3 of 7 circles here should be painted black to make the Masyu uniquely solved. Find them!
320 views

### Follow the path of relation through the grid #1

There is a relation between rectilinear-adjacent squares such that there is a unique rectilinear path from the top-left corner of the grid down to the bottom-right corner of the grid. Each square can ...
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 ...
6k views

### Creating a Kakuro puzzle with a unique solution

I start with a grid of black and white cells. I randomly populate the white cells from numbers (1-9) using Kakuro rules. Then I calculate the horizontal and vertical sums. I remove the numbers from ...
781 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 ...
870 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 ...
589 views

### A Puzzle in The Two Towers

Our local used book store is going out of business, and I ran in to pick up another copy of Lord of the Rings. When I picked up a likely copy, a scrap of paper fell out of The Two Towers...I've done ...
502 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 ...
259 views

### News of the world

Here's a quick little puzzle to keep busy.
793 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 ...
584 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 ...
633 views

### Linesweeper (Knight)

Draw a single loop which does not intersect itself by connecting pairs of cells which share an edge. The loop may not pass through any clue cells. Numbers indicate how many of the cells which the clue ...
1k 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.
570 views

### Cryptic Battle: Welcome to PSE!

Inspired by jafe's Double feature series. The following is a hybrid Star Battle and diagramless cryptic crossword. Solve the clues and the grid, then place the clued words in the grid in a logical ...
275 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 ...
696 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 ...
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 ...