# 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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### Introducing: Compoundoku!

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) ...
874 views

### Slightly Odd Sudoku

Someone I find very trustworthy continues to insist that this is a valid Sudoku board. It's been a while since I've played, but surely there's a couple of things off here, right? Alright, so that ...
1k views

### This new puzzle type needs a name {6}

I believe I have invented** a new type of puzzle... What is its name? Begin by solving the Fillomino puzzle: Rules of Fillomino (taken from Nikoli) Fill in all empty cells with numbers ...
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### Introducing Domidoku!

Come one, come all! Come see the new type of logic puzzle, the Domidoku! Here's a sample for all to try! The process is simple! First you solve the Sudoku and then you solve the Dominosa! ...
690 views

### 3D nonogram, beginner's edition

Trying out the concept of 3D nonograms. This one should be pretty simple. Name the depicted object.
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### Can you create a free-floating MASYU puzzle?

Rules of MASYU, for those unfamiliar: https://www.gmpuzzles.com/blog/masyu-rules-and-info/ Hey guys! So I just discovered this really cool puzzling site called the Puzzling Stack Exchange (puzzling....
924 views

### Complaint at the PSE lounge

While walking through the PSE lounge, I noticed a piece of paper on one of the tables. Picking it up, I saw several things. The first, was a couple of sentences at the top: I love this place! But ...
636 views

### Snakes on a Plane! 2

An entry in Fortnightly Topic Challenge #35: Restricted Title 1. Inspired by the title of this xkcd comic. Snakes ... on a plane ... again ... This time 2 specimens of a huge unknown type of snakes ...
502 views

### Statue View: Tetrominoes

This is a Statue View puzzle, an original invention combining two logic puzzle genres: Statue Park and Canal View. Rules of Statue View: Shade some cells of the grid to form the given set of pieces. ...
331 views

### Square Number Sudoku

Solve this diabolic Square Number Sudoku. Normal Sudoku Apply. Additionally, there are some rectangled area, in each area should be read as 1 number. The numbers must be SQUARE NUMBERS. There are: 1 1-...
770 views

### Square Spin #1: Sun and Moon

Defining Square Spin Lets play a game! The aim of this game is to transform one image into another using the least amount of moves possible. Here is what a move consists of: ...
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### Isometric Heyacrazy - Now In 3D!

This is a Heyacrazy puzzle on an isometric grid. Rules of Heyacrazy: Shade some cells of the grid. Shaded cells cannot be orthogonally adjacent; unshaded cells must be orthogonally connected. When ...
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### Chess Connect Puzzle

I made up a new logic puzzle based on the games Numberlink and Chess, and thought it ended up rather interesting. The solution, as usual, is unique. The starting and ending positions of 7 chess ...
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### A rook's tour of the chessboard

Place numbers 1 to 64 in the cells of this 8 x 8 board in such a way that consecutive numbers, and also numbers 1 and 64, occupy neighboring cells (either vertically or horizontally). Shaded cells ...
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### Heyawake: An Introductory Puzzle

This is a Heyawake ("divided rooms") puzzle. Rules of Heyawake: Shade some cells of the grid. Shaded cells cannot be orthogonally adjacent; unshaded cells must be orthogonally connected. ...
971 views

### Tic tac toe - Sudoku: A variation in which the centre box defines the layout of the other boxes

I stumbled across this interesting variation of Sudoku the other day and thought I'd give it a try, it has however baffled me and I've been unable to progress past the very early stages. The puzzle ...
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### Who can spot the difference?

My family and I have just moved house! Lucky us! So what did my family do? We held a housewarming party, and rung everyone in the neighbourhood up to invite them. So, anyway, people were coming in ...
871 views

### Masyu jigsaw puzzle

Here's a masyu puzzle for you. The rules are as follows Draw a single closed loop which does not cross or touch itself. The sections of the loop run horizontally or vertically between the ...
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### Make numbers 0 - 11 using the digits 2, 0, 1, 8; BUT

... seriously, this is definitely NOT that "kind of puzzle"! ;) So let me create this puzzle to freshen you up! It is inspired by a meta question: Yet another 2018 puzzle. Put the digits 2, 0, 1, ...
604 views

### Introducing Tetronogram - Beginner's Version

Introducing Tetronogram! (named by @MrPie) The puzzle is made of a grid like a nonogram. Notations are along the axes like a classic nonogram but numbers are replaced by the names of the ...
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### Introducing: Jormungand

An entry in Fortnightly Topic Challenge #32: Grid Deduction Hybrids Introducing: Jormungand A combination of Ouroboros (Slitherlink) and Numbersnake (Numbrix) to create the greatest snake-themed ...
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### This Nonogram seems a bit… off

Hmm...... Did I miss something? The hidden word has six unique letters anyway...... Hint 1: Hint 2: Hint 3: Addendum: There is a (very) minor fix to ensure the puzzle "uniquely solvable", adding 1-...
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### Shortest way from B to A

Spent most of my life out at sea I've crossed a shark or two ā or three Stayed calm ā a skipper brave and tough Yet one of them did call my bluff Gorged on my leg with glee Not yet ...
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### A letter from Mr. Pirate, Mr. Roller, and Mr. Knight

Though I don't think it will help, you may check with the beginning of my story concerning Red Herring Puzzle Club. It seems like it's been a long time since I tried to enter the R.H.P.C. As you may ...
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### Three for the price of one

While browsing through your local puzzle store, you see something you can't resist: a box which promises two grid deduction puzzles for the price of one! The vendor explains that the box contains a ...
558 views

### A colorful metapuzzle (of a sort)

edit: realized two puzzles ended up being variants. Replaced subpuzzle 5 completely, and swapped subpuzzle 2 to the original version. Either version has the same solution. edit 2: my apologies. this ...
394 views

### Prime number snake (2)

This question is inspired by prime number snake. In the following grid, you have to place a number snake of numbers 1 to 100. Consecutive numbers have to go into neighboring cells. Numbers in grey ...
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### A Total Masyu puzzle

In a Total Masyu puzzle, one must draw a single loop through the centres of some cells according to the following rules: The loop may only travel horizontally or vertically, never diagonally; all ...
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### A Knight's Kuromasu

An entry in Fortnightly Topic Challenge #32: Grid Deduction Hybrids You are a knight in the king's army, and you've been tasked with constructing some walls. The problem is, as a knight, you are ...
419 views

### Diabolical Deceptions: A 333rd Birthday Tribute to J.S. Bach

Johann Sebastian Bach is one of the most famous composers from the Baroque period. If he was still alive today, heād be 333 years old. So, letās celebrate 3 of his most famous works with a 33x33 loop ...
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### Tribute to Clifford Possum Tjapaltjarri

The background text that follows is in this case not part of the puzzle, nor fictitious. The puzzle, which is self-contained, consists entirely of the image below; I have composed it as a genuine (...
601 views

### What Masyu do with the antique clock?

Anagram is needed, and it will answer: What Masyu do with the antique clock?
620 views

### Another Rook's Tour

Place numbers 1 to 100 in the cells of this 10 x 10 board in such a way that consecutive numbers, and also numbers 1 and 100, occupy neighboring cells (either vertically or horizontally). Prime ...
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### Hexagonal Grid Filling

Fill in each blank white hexagon with a digit from 1 to 9. Each of the grey hexagons is the sum of the white hexagons around it, and all of the white hexagons that are around the same grey hexagon ...
266 views

### Queens of the Square Sudoku Table

. 6 . | 8 . 3 | . 7 . . . 1 | . . . | . 6 9 7 . . | . . . | . . 5 ---------+---------+-------- . . . | 9 . . | . 1 . . . . | . . . | . . 4 . . 5 | . 1 . | . ...
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### Sudoku with only 8 predefined numbers

Have fun with my self-made Sudoku puzzle. Solve this Sudoku puzzle using the standard Sudoku rules: Fill any row, column and bold-framed area with the numbers 1 to 9. Hint: It is not as difficult as ...
372 views

### Masyu-making game

Two players are playing a game on a $4\times4$ board. The players take turns adding either a white circle or a black circle into any empty square, so that the board makes a solvable masyu puzzle (with ...
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### This puzzle design was a DISASTER!

As any member of the PSE community knows, grid-deduction puzzles really aren't my forte. In fact, I'd like to share one particularly disasterous attempt at designing a Slitherlink puzzle. Disclaimer:...
817 views

### HAISU: Nought and Crosses

HAISU is a portmanteau of three Japanese words - 'hairu', to enter, 'su', number, and 'hausu', an English borrow word meaning house, of course. Together, we get a meaning of 'enter number house', ...
597 views

### Octagonal Kurotto

This is a Kurotto puzzle. Rules of Kurotto: Shade some cells to form connected groups of shaded cells. Circled cells are unshaded. If they have a number in them, that number tells you the sum ...
508 views

### Tiling a square with rectangles

Tile completely this 47 x 47 square with 52 rectangles. Each rectangle must contain precisely one numbered cell, and that number must be the area or perimeter of the rectangle it finds itself in. ...
475 views

### Unusual Kakuro Puzzle

Entry into Fortnightly Topic Challenge #38: Reusing Information 1 This puzzle sort of looks like a kakuro puzzle but there doesn't seem to be any sums. Figure out how this puzzle works and solve the ...
488 views

### Karst - A variant of Cave

This is a variant of Cave applied to a 3.4.6.4; 3.42 6; 44 tiling. Rules Draw a single loop along the dashed lines that encloses some cells. Edges of this loop may not cross or share a ...
762 views

### Time to Hit the Bricks!

An entry in Fortnightly Topic Challenge #24: Grid-Deduction... It's 2am. The phone rings. You answer it and are immediately met with an onslaught of franticness from your (in?)famous uncle—a ...
526 views

### Heyawacky: Ace of Cups

This is a Heyawacky puzzle. The rules are the same as Heyawake, but non-rectangular regions are allowed. Rules of Heyawake: Shade some cells of the grid. Shaded cells cannot be orthogonally adjacent;...
507 views

### HAISU: One Piece

This is a Haisu puzzle. Draw a path from S to G passing through all cells exactly once by connecting the centres of adjacent cells, such that when the path passes over a number N, it is on its Nth ...
637 views

### This new puzzle type needs a name {5}

I believe I have invented a new type of puzzle... What is its name? Colour-blind-friendly version available here. Begin by solving the 9x9 sudoku; each of the 9 symbols ...
759 views

### On The Subject of Battleships

(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 ...
654 views

### Statue Park: Knight's Lines

This is a Statue Park puzzle. Rules of Statue Park: Shade some cells of the grid to form the given set of pieces. Pieces may be rotated or reflected. Pieces cannot be orthogonally adjacent (though ...