# 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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### 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.
1 vote
238 views

### 9x9 Sudoku Puzzle

This is a standard 9x9 sudoku puzzle from a book I hope to publish:
109 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 ...
138 views

### 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.
1 vote
133 views

### 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 ...
337 views

### 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 ...
1 vote
141 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 ...
• 193
757 views

### 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 ...
• 289
173 views

### 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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604 views

### 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, ...
• 3,461
838 views

### 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 ...
• 295
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### 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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215 views

### 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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### Can every Sudoku puzzle be solved without brute force? [duplicate]

So I wrote up an algorithm for generating Sudoku boards, and it generated the following board: I was trying to solve it on my own and got stuck, which prompted me to try putting it in this website. ...
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534 views

### 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 ...
• 221
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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.
• 33
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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 ...
• 518
805 views

### 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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278 views

### A tough sudoku puzzle

Here is a tough sudoku puzzle from my blog
222 views

### Easy Sudoku Puzzle

This is an easy sudoku puzzle (no. 90) from my blog.
782 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, ...
• 10.5k
174 views

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 ...
• 3,771
153 views

### 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 ...
886 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 ...
696 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 ...
• 4,298
779 views

### 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, ...
• 71
192 views

### 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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411 views

### Cartological Cats: A Snaky-Loop Grid Puzzle with Cat-Shaped Matchmaking Clues

This is written for calica for a Secret Santa puzzle exchange. The original version in a printable PDF format can be found here. Dear calica, Thank you so much for being an amazing person this year! ...
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110 views

### Is X-Sudoku easier to solve than classic Sudoku [closed]

X-Sudoku has extra rule for diagonals which give extra hints for diagonal cells. Does this implies that solving X-Sudoku puzzles are easier than classic Sudoku puzzles?
2k views

### What is this puzzle?

$$\huge\text{This puzzle is _______}$$
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### Finding a Kakuro trick

The following screenshot is taken from the Android app Kakuro++ (level 9 riddle 12) And I verified the current status within the app. I managed to solve the puzzle by guessing a 50/50-number and ...
• 645
254 views

### Snowcaps - A grid deduction puzzle

This winter-themed puzzle is basically an upside-down Aquarium, the idea being that instead of fish tanks being filled with water, the areas are mountains being covered with snow. The goal is to shade ...
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558 views

### PSE Advent Calendar 2021 (Day 24): The Witneys - Your Comfy Puzzles

This puzzle is part of the Puzzling StackExchange Advent Calendar 2021. The accepted answer to this question will be awarded a bounty worth 200 reputation.< Previous Door Your great-grandmother ...
• 33.7k
686 views

### PSE Advent Calendar 2021 (Day 20): Candy Cane Sudoku

This puzzle is part of the Puzzling Stack Exchange Advent Calendar 2021. The accepted answer to this question will be awarded a bounty worth 50 reputation.< Previous Door Next Door > So I was ...
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507 views

### PSE Advent Calendar 2021 (Day 19): Santa's Dilemma

This puzzle is part of the Puzzling Stack Exchange Advent Calendar 2021. The accepted answer to this question will be awarded a bounty worth 100 reputation.< Previous Door Next Door > It was ...
• 1,559
454 views

### PSE Advent Calendar 2021 (Day 17): That's the way the cookie crumbles

This puzzle is part of the Puzzling StackExchange Advent Calendar 2021. The accepted answer to this question will be awarded a bounty worth 50 reputation.< Previous Door Next Door > In our house,...
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579 views

### PSE Advent Calendar 2021 (Day 15): Optics Experiment

This puzzle is part of the Puzzling StackExchange Advent Calendar 2021. The accepted answer to this question will be awarded a bounty worth 50 reputation.< Previous Door Next Door > Optics ...
• 484
482 views

### Christmas tree LITSO

Inspired by PSE Advent Calendar 2021 (Day 13): A Christmas Hokuro, I challenged myself to create a Christmas tree-shaped puzzle. Unfortunately I had to edit the shape a little bit because... reasons. ...
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633 views

### PSE Advent Calendar 2021 (Day 13): A Christmas Hokuro

This puzzle is part of the Puzzling StackExchange Advent Calendar 2021. The accepted answer to this question will be awarded a bounty worth 50 reputation.< Previous Door Next Door > Hokuro is a ...
• 4,298
203 views

### Place digits from 1 to 7 into each row and each column of the grid once. Numbers in the circles give the product of the four surrounding digits

What is the way to resolve the following puzzle? Link to source. It's from a taiwanese math olympiad held in 2005.
• 71
628 views

### PSE Advent Calendar 2021 (Day 4): Decorating with Ingrid Deduction

This puzzle is part of the Puzzling StackExchange Advent Calendar 2021. The accepted answer to this question will be awarded a bounty worth 50 reputation. < Previous Door Next Door > "...
• 23.9k
725 views

### PSE Advent Calendar 2021 (Day 3): Tentai Show

This puzzle is part of the Puzzling StackExchange Advent Calendar 2021. The accepted answer to this question will be awarded a bounty worth 50 reputation.< Previous Door Next Door > Divide the ...
• 67k
263 views

### 10x10 Fillomino

Interactive solving website For help/rules on solving, please look at the website's "help" section, which lists fillomino rules. Please use the website to solve the puzzle unless you are ...
1k views

### The Golden Age of Sudoku

Rules: Each cell contains one of the following symbols: A23456789TJQK. No two cells in the same row or column have the same symbol. The grid is divided into 11 square regions of different sizes. A ...
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