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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1answer
208 views

Statue Park (Loop)

Place each of the twelve pentominoes into the grid once, with rotations and reflections allowed. No two pentominoes can overlap or be orthogonally adjacent, and all cells not occupied by the ...
8
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4answers
407 views

A “Find the Path” Puzzle

I invented a puzzle, inspired by Simon Tatham's Portable Puzzle Collection. Is there anything that it could improve on? Was it too easy, or was it too hard? Anything I could add? What must I call it? ...
14
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1answer
319 views

Finding the hidden path (new grid puzzle concept?)

I was toying around with grid-based puzzles, and I can up with a format that I'm not sure exists yet, and from my testing leaves only one solution. (If it exists or is broken, please let me know so I ...
4
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2answers
222 views

Sto-stone puzzle

Sto-stone is a puzzle made by Nikoli. Here are the rules: You must color the cells with black with the following rules: There are rooms enclosed in bold lines. The number on the room shows the ...
17
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2answers
391 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 ...
26
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2answers
1k views

HAISU (Room Count): An original grid-logic challenge

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', ...
14
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1answer
378 views

HAISU with a twist

HAISU is a grid-deduction puzzle designed by this site's very own TheGreatEscaper. To quote them: HAISU is a portmanteau of three Japanese words - 'hairu', to enter, 'su', number, and 'hausu', an ...
32
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4answers
2k views

WITLESS - A Puzzling Journey

IMPORTANT! READ ME: The only 'puzzle' parts of this are the links, titled 'Set X', 'Inscription X', or 'Constellation X'. Everything else is flavortext, apart from this readme section, although the ...
23
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2answers
802 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 ...
7
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3answers
508 views

Slitherlink the second

Find the solution to this slitherlink puzzle that I came up with: This one's even smaller!
8
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1answer
243 views

Unusual Sudoku Puzzle

Find the solution to this Sudoku puzzle. The only problem is there aren't any normal Sudoku clues. Instead there are only some cryptic clues. What is the solution and how does the puzzle work? Edit: ...
8
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4answers
493 views

The Knights and the Hounds

(With thanks and congratulations to Lee Leon) We rejoin our heroes several days after the events of The Knights' Gift, at the head of a pack of enormous staghounds, 1000 strong. Such a pack ...
29
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1answer
595 views

Pikurossword, or: Three-in-One

This is an entry into the Fortnightly Topic Challenge #36. [edit: i hope this wasn't too bad for my first puzzle here! let me know how i did :)] The answer to this puzzle should answer the question: ...
15
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2answers
511 views

Hitchhiker's guide to Scrabble

I was working at My God, it's full of stars! puzzle, when a sudden realisation came into my head: that I have a friend, who is also an astronaut, and that I have an appointment with him! We were ...
52
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4answers
2k views

Desert Irrigation Project

An entry in Fortnightly Topic Challenge #32: Grid Deduction Hybrids My dear friend researches and designs canal irrigation systems in a remote desert. He's been missing for two weeks. Members of ...
39
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2answers
1k views

Circuit Diagram

An entry to Fortnightly Topic Challenge #35: Restricted Title 1 - based on the following xkcd. Circuit diagrams can be quite difficult to understand, so here are some documents that will hopefully ...
16
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1answer
586 views

Barrel - Part 1

An entry in Fortnightly Topic Challenge #35: Restricted Title 1. Title based on the very first xkcd. Continued in Barrel - Part 2, Barrel - Part 3, Barrel - Part 4, and Barrel - Part 5. You manage a ...
19
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8answers
1k views

Shortest way from B to A

Spent most of my life out at sea I've crossed a shark or two – or three Stayed calm – a skipper brave and tough Yet one of them did call my bluff Gorged on my leg with glee Not yet ...
21
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1answer
609 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 ...
28
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5answers
2k views

Making Things Difficult

An entry in Fortnightly Topic Challenge #35: Restricted Title 1. Factoring the Time Think fast! If you're looking for meaning, these clocks have some for you. Keyboards are Disgusting Gunky ...
24
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1answer
551 views

Stingray Nebula

An entry in Fortnightly Topic Challenge #35: Restricted Title 1. Inspired by the title of this xkcd comic, but in no way related or affiliated beyond the shared name. This is the stingray nebula: ...
12
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1answer
403 views
11
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1answer
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 ...
12
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2answers
440 views

Slitherlink with crossing allowed

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 ...
14
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1answer
359 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? ...
20
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1answer
1k views

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 ...
25
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2answers
502 views

Popularity Within a Target Audience

This is a metapuzzle with four component puzzles and a final meta. Creations of CSIRO The Australian research institute CSIRO is notable for producing inventions such as gene shears, the insect ...
9
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0answers
366 views

Grandma's keynote

Found this note which is addressed To my grandma, in her chest Since she's passed now, here's my quest.. What tickled her interest? And who invited her as guest?
33
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2answers
3k views

I've been everywhere, man

I am a knight facing a plight My dearest one of all Lives in a tower and won’t come out Unless her name I call I went to pick her up today And though my mind was set To do so, as I ...
9
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1answer
480 views

Ripple effects: A suite of puzzles and conundrums

Best explained here. Basically there are two rules: fill in each region with the numbers 1 to N, where N is the size of that region two numbers, both K, cannot both be in the same row or column if ...
8
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2answers
1k views

Fill this 5x5 number grid incrementally, either by moving two boxes diagonally or moving three boxes in a row or column

One day, a friend has shown me a 5 by 5 grid, challenging me to fill it with numbers from 1 to 25. Obviously, it is not simple because there are some rules: The number 1 is placed in the center of ...
7
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1answer
352 views

Latin square puzzle

This is a sudoku-esque puzzle I came up with when trying to solve some harder sudoku. The rules It’s a Latin square like sudoku, so there must be the numbers 1-9 exactly once in every row and ...
7
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1answer
195 views

Latin Square Puzzle - Difficult

Follow on puzzle from the introductory Latin square puzzle post. The rules It’s a Latin square like sudoku, so there must be the numbers 1-9 exactly once in every row and column. Notice that each ...
64
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2answers
5k views

Happy Pi-Day! Try to solve this “PiDoku”

To celebrate the Pi-Day (3/14) adequately, a challenging math puzzle must not be missing. Rules: Fill in the numbers 1-9 exactly once in every row, column, and region. On top of that, you need to ...
8
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1answer
283 views

Backwards Boggle

I came up with a fun little 1-player puzzle for myself to do when bored. Pick 5-6 words, preferably words that share a good number of letters, and try to create a Boggle board containing all of those ...
6
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2answers
370 views

How does one go about creating a new grid-deduction puzzle?

The grid-deduction tag covers puzzles like Sudoku, Kakuro, etc. where the goal is to fill in a grid of numbers [/letters/colours] in a unique way by logical deduction from some predetermined rules and ...
27
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1answer
871 views

You go wherever you go today

A conclusion to my entries in the Fortnightly Topic Challenge #32: Grid Deduction Hybrids. This metapuzzle incorporates the three previous puzzles in this series: Desert Irrigation Project I am an ...
3
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4answers
686 views

Flow Free Favourites

Recently, I have been amusing myself with the interesting puzzles provided by the excellent Flow Free puzzle app. Since I couldn't find a way to bookmark my favourite puzzles, I took up a habit of ...
19
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1answer
2k views

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, ...
4
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1answer
126 views

RPS Trinity - Teddy and Her Ribbon

The Rules of RPS Trinity: You are given a board with its tiles colored either black or white. Put Rocks (denoted by letter R), Papers (denoted by letter P), and Scissors (denoted by letter S) on ...
7
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1answer
480 views

Two Christmas trees

To each Christmas tree : Put two $+$, two $-$, and two $×$, to the yellow triangles. in a row, there must be different operators (so between $[2,0,1,7]$ all $3$ operators must appear) $A - B$ means $|...
45
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1answer
2k views

Japanese Fusion Alphabet Soup

The Dish... ...is an intriguing blend, with a base of classic Western flavours, and a twist of the Orient at its heart. The Ingredients... ...are diverse and are combined in such an unexpected - ...
15
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2answers
898 views

25x25 slitherlink puzzle

Basic rules Form a loop using the dots (so, by joining orthogonally adjacent dots) such that a number N is surrounded by exactly N segments of the loop. Here's a tutorial puzzle and its unique ...
6
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1answer
449 views

Hashiwokakero Puzzle

Rules: Connect islands (the circles with numbers) with as many bridges as the number in the island. Bridges can go only in a straight line horizontally or vertically. There can be no more than two ...
5
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1answer
170 views

Sums to a square number

arrange the numbers 0 to 9 in the circles below, following these rules : Every row of 3 or 4 circles sums to a square number. Every diagonal of 3 circles sums to a square number. Every green circle ...
12
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1answer
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 ...
7
votes
1answer
279 views

Connected circles which sum of any two of them which are adjacent is a triangle numbers

Arrange numbers 1 to 36 to the small circles and ovals, with rules: sum of any two of them which are adjacent is a triangle numbers. The first 12 Triangle numbers are 0, 1, 3, 6, 10, 15, 21, 28, 36, ...
10
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1answer
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 ...
13
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2answers
542 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×...
9
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2answers
514 views

Tetromi-nuri-doku

Note: This puzzle was inspired by the one here, by Mike Q. Every square in the grid above, when the puzzle is complete, has a number between 1 and 9 in it and either is shaded or is not. Each 3x3 ...