# 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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### Self-reflections

Copying is a form of praise (some say). And I will be honest for a change; I am just a thief. And as such: I am lazy (yellow) I (mis)interpret the rules whenever convenient. (red) Things got more ...
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### Make sense of the grids

Make sense of the following two grids using the visual clues. Both grids have a common theme. What do they say? GRID 1 GRID 2
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### Shaka/shawaka: Trominoes

This is a shaka/shawaka puzzle. Place black triangles in some white cells in the grid – formed by dividing a cell diagonally and painting one side black – so that each remaining white area forms the ...
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### a six-by-six KenKen

The rules of KenKen are as follows: You must fill in the numbers 1 through 6, one number per box, in the grid, so each row and each column contains each number exactly once. Each heavily outlined ...
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### Food over friendship

This is supposed to be pretty simple so don't overthink it. Four friends, Larry, Ivan, Tom and Sam, all want to eat a well-drawn apple. Can you tell which of them can get to it?
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### Shaka/shawaka: An introduction

This is a shaka/shawaka puzzle. Place black triangles in some white cells in the grid – formed by dividing a cell diagonally and painting one side black – so that each remaining white area forms the ...
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### Logical Deduction Persistence Test

In the grid below, create a path that starts at cell 1 and ends at cell 49, moving horizontally and vertically only. The path must touch each of the 49 cells exactly once and contain a: A. Maximum of ...
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862 views

Here is a time waster for you : ) Transcript of the image: ...
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This grid contains 3 puzzles all in one; 0h n0, a Crossword and a Wordoku (Sudoku with letters)... ...but first you'll need to build it. 0h n0 Cells can 'see' other blue cells in the same row and ...
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### Pseudo Roman Cipher

A while ago, I made this puzzle and gave it to my friend. But his comment was not so good. "This looks fine except it's not realistic", he said. I know he is smart but ... :( I don't want to ...
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### Another pseudo-IQ question

This puzzle is part of the Monthly Topic Challenge #2: IQ Puzzle Parody People keep asking me if there's anything between me and my good friend Ingrid Deduction... Well, it's... complicated... We go ...
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### My IQ will be so high if someone can solve this for me

This puzzle is part of the Monthly Topic Challenge #2: IQ Puzzle Parody I'm stumped with the IQ test question below. Can anyone give me a hand so I can prove how smart I am? Which of the three ...
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### How do I solve this unreasonable 6x6 game of Towers without backtracking?

I'm playing Towers by Simon Tatham (rules are in the link). This game shares some solution logic to Sudoku. I recently moved to the last suggested level of difficulty, 6x6 Unreasonable, but I ...
868 views

### Help! Help! My IQ!

This puzzle is part of the Monthly Topic Challenge #2: IQ Puzzle Parody Help! I'm trying to score a 100 from this online IQ test but can't figure out some of the questions. Below is an example, with ...
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### Surprisingly Challenging "Normal Difficulty" Star Battle?

I was demoing the Star Battle puzzle type to a friend, and got promptly embarrassed by having to bifurcate in order to solve this puzzle: https://www.puzzle-star-battle.com/?pl=...
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### Solving Sudoku purely by logic: why does this X-cycle choose this cell?

I've been reading several articles on difficult Sudoku puzzles and whether "guessing" is ever acceptable. The attached image shows the stage I reached using only deduction but at this point ...
946 views

### Objects in Mirror

This puzzle is part of the Monthly Topic Challenge #1: Restricted Title: xkcd 1xxx and is based on https://xkcd.com/1125/. [Penpa link at the bottom, if you want to skip the story] Objects in Mirror ....
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### My Pentadoku puzzles (Jigsaw Sudoku)

In each of the following puzzles, fill the empty squares with numbers so that every row, column and irregularly shaped region contains the numbers 1, 2, 3, 4 and 5 exactly once.
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### My Fill-the-circles puzzles (Set #3)

In each puzzle, fill the circles with the numbers 1, 2, 3, ... n, where n is the number of circles in such a way that consecutive numbers are NOT in circles that are joined by a line.
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1 vote
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### 9x9 Sudoku Puzzle

This is a standard 9x9 sudoku puzzle from a book I hope to publish:
179 views

### My Fill-the-circles puzzles (Set #2)

In each puzzle, fill the circles with the numbers 1, 2, 3, ... n, where n is the number of circles in such a way that consecutive numbers are NOT in circles that are joined with a line. I designed all ...
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### My Fill-the-circles puzzles (Set # 1)

In each puzzle, fill the circles with the numbers 1, 2, 3, ... n, where n is the number of circles in such a way that consecutive numbers are NOT in circles that are joined with a line.
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1 vote
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### More of my Find-the-stars puzzles (Set #2)

Find-the-stars instructions: A Find-the-stars puzzle is played on a square grid that is initially empty except some squares contain arrows. The goal of the puzzle is to fill some empty squares with ...
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### Three of my Find-the-stars puzzles

Find-the-stars instructions: A Find-the-stars puzzle is played on a square grid that is initially empty except some squares contain arrows. The goal of the puzzle is to fill some empty squares with ...
• 5,878
1 vote
232 views

### Honeycomb puzzle with hexagons [closed]

Can you place the numbers 1 through 9 in the honeycomb so that the sum of the numbers in the adjacent hexagons is a multiple of the number in the hexagons? This must be true in all hexagons. The top ...
2k views

### Colour in a 5 by 5 grid, with evolution rules, so that the starting grid is the same as the output grid

Colour in a 5 by 5 grid using the colours Red, Blue, Green and Yellow. Each cell is considered to have 4 neighbours (to the left, right, above and below.) The grid wraps, so e.g. the top right is a ...
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### How to solve this Pentomino puzzle?

The following Pentomino board has exactly one solution: The solution is known: I'm trying to solve this board manually, but it is so difficult that I came to believe it is impossible. I noticed ...
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### Rong-rong (ring-ring variation)

I was thinking about ring-ring puzzle. Suddenly, the 'word' rong-rong came to my mind and made me laugh for no reason. So, I'm messing around with ring-ring rules that fit the rong-rong 'word'. Rules:...
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### Next step in this Slitherlink puzzle?

I am playing this Slitherlink app on Android, and get stuck on this puzzle at the following state: I made a lot of progress on the right side, but after this I couldn't find anything that I can do, ...
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### A Simple Loop with A Poetry?

Who is he really? Please answer this question of mine Starting from the top-leftmost white cell and then You are still going clockwise by Taking the letters where you are turning left but Not, once ...
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### Is the "rocket" pattern inversible?

The rocket pattern in slitherlink is when a 3 sees a 1 in a diagonal, with two crosses (the exhaust) on the opposite side. 3 x 1 x two lines can be added ...
444 views

### How to prove Yin-Yang alternating 2 by 2 is not allowed

Yin-Yang is a puzzle where one needs to fill each cells with either black circle or white circle following these rules: Each color's circles must be connected to one another according to four-way ...
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### The Wrong Products

Rules: Place each number from 1 to 12 exactly once such that every row and column contains exactly two numbers. Clues outside the grid show the product of the two numbers in that row/column. However, ...
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### A massive synonym

Please explain how to assemble the puzzle. Yes, one is missing, but you can follow the >. No computers. Hint: Hint 2: Hint 3: Text version: ...
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### What is the next move on this minesweeper board?

Here is the board I found an online minesweeper solver which can deduce what the next move is, so I know what the next move is and that it is logically obtainable. But it doesn't offer much help in ...
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### SNES Super Picross - Mario SP-I

Currently stuck on Super Picross and looking for a hint for the next logical deduction on Mario stage SP-I.
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### Mega Circles And Squares

Since recently Athin showed Circles And Squares, a genre which I invented and am very proud of, I thought "Hey, why not give another one!" But this time, I'm sharing one that I made for both ...
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### Circles and Squares - A Grid Puzzle

This relatively new grid puzzle genre is invented by Anonymus25. Rules of Circles and Squares: Shade some cells so that all shaded cells form one orthogonally connected area and each orthogonally ...
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### A tough sudoku puzzle

Here is a tough sudoku puzzle from my blog
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### Easy Sudoku Puzzle

This is an easy sudoku puzzle (no. 90) from my blog.
824 views

### Tic-Tac-Collatz

Have you ever heard of the Collatz conjecture? Just in case you haven't, I'll summarize it for you! Take any positive integer $n$, if it is even then simply divide it by $2$; however, if it is odd, ...
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I recently learned what a Slitherlink puzzle is; from here, so I tried my hand at making one! This is a normal 7x7 slitherlink, but with the added restriction that the loop must form the number 2 in ...
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### Slitherlink #1 - Very Simple [closed]

This is a simple slitherlink, which is very easy. The rules are as follows (suggested by @bobble and @PuzzlingFerret): There can be multiple loops. The final solution should be a shape. Congrats to ...
1k views

### Snakes and Adders - A New Grid Puzzle

So, literally last night, I dreamt of this new grid puzzle genre, so I'm just giving it a shot... Rules of Snake and Adders: Put some snakes into the grid on the white cells. Each snake forms a ...
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### Can you solve this gogen puzzle?

I created this gogen puzzle myself: Add the 25 letters between A and Y to the grid above. Each one should appear exactly once. When you have finished, you must be able to spell the following words ...
746 views

### →Triple Hokuro←

Hokuro is a grid deduction puzzle inspired by Kakuro. Basic Hokuro rules Each cell contains one of the following symbols: Each arrow indicates a step in that direction, while the dot indicates no ...
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### Binary Sudoku Puzzle

The rules of Binary Sudoku are quite simple. It is very similar to regular Sudoku, except here we try to fill a 9x9 board with only black and white tiles following the below rules: Every row, column, ...
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### Mario's Super Picross - Stage Mario 9-K

I'm playing through Mario's Super Picross currently and after nearly 200 puzzles this one finally has me stumped as to how it is intended to be solved. What is the next step to solving this? Notes: ...
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