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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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39
votes
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
votes
1answer
599 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
votes
1answer
620 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
votes
1answer
562 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
votes
1answer
404 views
11
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1answer
459 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
votes
2answers
449 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
votes
1answer
371 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
votes
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
votes
2answers
515 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
votes
0answers
386 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
votes
1answer
487 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
votes
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
votes
1answer
383 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
votes
1answer
207 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
votes
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
votes
1answer
316 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
votes
2answers
393 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
votes
1answer
884 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
votes
4answers
690 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
votes
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
votes
1answer
131 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
votes
1answer
482 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
votes
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
votes
2answers
911 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
votes
1answer
462 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
votes
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
votes
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
282 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
votes
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
votes
2answers
552 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
votes
2answers
529 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 ...
10
votes
3answers
940 views

A “Letter” Slope puzzle?

Your brother has been forcing you to some read some of his frankly ridiculous poetry, so, knowing that he was never a numbers man, you decide to vex him with a Number Slope puzzle. In fact, you are so ...
5
votes
2answers
791 views

Special Sudoku, with windows pattern

Solve this Sudoku, with rules : Every blue square means, it is the left-top of a 3x3 block with each numbers [1 to 9] appearing only once there. There is only one unique solution. Check the example. ...
3
votes
1answer
189 views

Fill the table so every consecutive 3 numbers sums to 50 or 100

Arrange numbers 1 to 40 to the table with rules: Multiple of 4 Numbers and some perfect square numbers are already there as guide. Every 3 consecutive numbers with pattern white-yellow-white, must ...
7
votes
1answer
871 views

Solve this Subtraction sudoku!

This is subtraction sudoku. The rules are basically the same as common Sudoku, but with a few additions. In the row, the number in the orange box is the difference when its left side (sum of 3 ...
4
votes
2answers
324 views

Find the ? in this grid

Find question mark in this grid with numbers. csv version: 9,6,7,3 2,4,7,6 4,1,5,8 3,0,3,? Hint: You use all numbers to find ? and it is much more simple ...
10
votes
1answer
469 views

5x5 Grid with all two digit numbers

There is a $5\times5$ grid where you are supposed to put all two digit numbers which consist only of the digits $1$ to $5$, namely $11,12,13,14,15$,$21,22$,.... The task is to put all these two digit ...
7
votes
2answers
814 views

Fill numbers to the star shaped puzzle

Fill in all the blank circle with numbers 1 to 6, so : Each lines of 6 circles, contains 6 different numbers. Each corner (consist of 3 greens circle) sums to 11. There is only 1 unique solution.
52
votes
1answer
2k views

The Ludicrous Loop: over a thousand cells of circular logic!

Flavourtext is for flavour only. Ladies and Gentlemen, are you feeling ludicrous today? A little loopy, perhaps? Then come one, come all, for I have just the thing for you. Lampreys and Jellyfish, ...
9
votes
2answers
253 views

4 pieces into a big slitherlink

Arrange the 4 pieces into a big slitherlink. To help you arrange it, First find the solvable small slitherlink then put it in the bottom-left position. 1st piece 2nd piece 3rd piece 4th piece
6
votes
4answers
1k views

Filling the board with 0s and 1s

You are given a $9\times9$ grid board. You have 40 "$1$"s and 41 "$0$"s. You can put these numbers wherever you want on the board. After that, you will take the sum of the numbers in each row and ...
8
votes
1answer
745 views

13-by-13 SIKAKU puzzle

A SIKAKU puzzle consists of a square or rectangular grid in which some of the cells contain a one or two digit number. To complete the puzzle, a Solver must divide the puzzle into a number of ...
13
votes
2answers
550 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 ...
11
votes
1answer
1k views

Futoshiki Puzzle with the least amount of clue

You are supposed to create a new $5$x$5$ Futoshiki puzzle with the least amount of clues possible, but this puzzle needs a unique answer. In other words, What is the minimum number of clues for $5$...
4
votes
2answers
203 views

Modified Futoshiki

This is a modified Futoshiki Place the numbers 1 to 5 such that each row, and column contains each of the digits 1 to 5. Squares with same color, contains each of the digits 1 to 5 too.
32
votes
2answers
1k views

fill this grid with water!

In this puzzle you should fill the imaginary small squares in each row and column up to the number that is written next to it with water. You can't fill a square if the squares connected to it(under ...