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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6
votes
1answer
257 views

Double feature: Going postal

This puzzle is part 8 of the Double feature series (first part here). The series will continue in "Double feature: Unpopular". Rules of Yajilin1 Shade some cells in the grid. The ...
9
votes
1answer
409 views

Double feature: Weightier

This puzzle is part 7 of the Double feature series (first part here). The series will continue in "Double feature: Going postal". Rules of Statue View1 Insert the four given pieces (<...
10
votes
1answer
414 views

Double feature: Legal trouble

This puzzle is part 6 of the Double feature series (first part here). The series will continue in "Double feature: Weightier". Rules of Hitori1 Shade some cells in the grid. No ...
9
votes
2answers
474 views

Double feature: In cold blood

This puzzle is part 5 of the Double feature series (first part here). The series will continue in "Double feature: Legal trouble". Rules of Nurikabe1 Shade some cells in the grid. ...
5
votes
1answer
278 views

Double feature: Hot stuff

This puzzle is part 4 of the Double feature series (first part here). The series will continue in "Double feature: In cold blood". Rules of Heyawake1 Shade some cells in the grid. ...
13
votes
2answers
1k views

Twelve Labours - #02 Lernaean Hydration

This puzzle is part of the ‘Twelve Labours’ series. Previous instalments can be found here: Prologue | 01 His first labour now complete, Hercules made his way up the street to the storage depot for ...
11
votes
1answer
316 views

Masyu keep making those 3D puzzles?

This is a three-dimensional Masyu puzzle. The five squares depict the layers of a $5\times5\times5$ cube. The goal is to make a single loop in 3D space which fulfills the following properties: The ...
13
votes
1answer
355 views

Piece de Resistance - Jack in all Tags… But Master in All?

Jack in all Tags... But Master in All? This puzzle is part of the "Piece de Resistance" series. Go back to Part 1 (Ace) for the story.Ace Two Three Four Five Six Seven Eight Nine Ten Queen King... ...
8
votes
2answers
366 views

Double feature: In concert

This puzzle is part 3 of the Double feature series (first part here). The series will continue in "Double feature: Hot stuff". Rules of Ripple Effect1 Fill the grid so that each cell ...
8
votes
1answer
317 views

Double feature: Russian desman

This puzzle is part 2 of the Double feature series (first part here). The series will continue in "Double feature: In concert". Rules of Masyu1 Make a single loop which goes through ...
12
votes
1answer
646 views

Double feature: Braaains

This puzzle is part 1 of the Double feature series. The series will continue in "Double feature: Russian desman". Rules of Akari (also known as Light Up)1 Insert light bulbs into any ...
8
votes
2answers
349 views

Spiral Stumper Series: Instructionless Puzzle

Spiral Stumper Series is a $5$-puzzles series taken from the Final Round of a local (national) contest, KPK, which has been ended recently and authored by me. The theme is spiral and each puzzle is ...
4
votes
1answer
169 views

Spiral Stumper Series: Ripple Effect

Spiral Stumper Series is a $5$-puzzles series taken from the Final Round of a local (national) contest, KPK, which has been ended recently and authored by me. The theme is spiral and each puzzle is ...
6
votes
1answer
135 views

A Curve of Pursuit Yajilin

Following on from my previous Yajilin, I wanted to make a harder one for your entertainment and amusement, and hopefully to keep @Deusovi occupied for more than 20 minutes. Rules (shamelessly ...
5
votes
1answer
203 views

Spiral Stumper Series: Fillomino

Spiral Stumper Series is a $5$-puzzles series taken from the Final Round of a local (national) contest, KPK, which has been ended recently and authored by me. The theme is spiral and each puzzle is ...
6
votes
1answer
383 views

A symmetrical Yajilin

Inspired by @Athin's efforts, I decided to try to come up with a Yajilin puzzle of my own for your entertainment and amusement. Rules (shamelessly stolen from @Athin's post) Draw a line to ...
4
votes
1answer
130 views

Spiral Stumper Series: Kurodoko

Spiral Stumper Series is a $5$-puzzles series taken from the Final Round of a local (national) contest, KPK, which has been ended recently and authored by me. The theme is spiral and each puzzle is ...
7
votes
1answer
244 views

Nurikabe: Sixes

This is a Nurikabe puzzle. The goal is to paint some cells black so that the resulting grid satisfies the rules1 of Nurikabe: Numbered cells are white. White cells are divided into regions, all of ...
4
votes
2answers
119 views

Spiral Stumper Series: Tilepaint

Spiral Stumper Series is a $5$-puzzles series taken from the Final Round of a local (national) contest, KPK, which has been ended recently and authored by me. The theme is spiral and each puzzle is ...
40
votes
2answers
1k views

Magic Maze Puzzle

Inspired by the board game, Magic Maze Set-up: Cut out each 4x4 tile, and the four small tokens (orange, yellow, green and purple), from the provided image below. Place tile 1 on a flat surface with ...
7
votes
2answers
386 views

Quick Yajilin Puzzles: Scatter and Gather

Yajilin (adapted from Nikoli) Draw a line to make a single loop. Lines pass through the centers of cells, horizontally, vertically, or turning. The loop never crosses itself, branches off, ...
6
votes
1answer
208 views

What's the next step in this Unequal (Futoshiki) puzzle?

I'm currently stuck on this puzzle from Simon Tatham's website (he calls it "Unequal", although the standard name according to Wikipedia is Futoshiki). My progress so far is: I've even tried a few "...
11
votes
3answers
604 views

Quick Kurodoko Puzzle: Threes and Triples

Kurodoko (taken from Nikoli) Colour cells black according to the following rules. The numbers on the board show the number of white cells from the number to the nearest black cell or to the ...
8
votes
1answer
207 views

Nurikabe minicubes: the Headache, the Panache, the Apache

These are three-dimensional Nurikabe puzzles. In each case, the four squares represent the layers of a $4\times4\times4$ cube. The goal is to shade some cells in each layer so that the resulting space ...
6
votes
1answer
228 views

Piece de Resistance - Eight Doubled Tetrominoes Make a Tetronogram

Eight Doubled Tetrominoes Make a Tetronogram This puzzle is part of the "Piece de Resistance" series. Go back to Part 1 (Ace) for the story.Ace Two Three Four Five Six Seven Eight ... Time for ...
12
votes
1answer
158 views

Geisterbahn 2.0

This puzzle was inspired by the ruleset of Round 3 of the German Logic Masters 2019: Geisterbahn 2.0 Place the numbers 2 or 3 in some cells such that all the numbers are connected orthogonally, no ...
7
votes
2answers
255 views

Quick Shikaku Puzzle: Stars and Stripes

Shikaku (taken from Nikoli) Divide the grid into rectangles with the numbers in the cells. Each rectangle is to contain exactly one number and it's showing the number of cells in the ...
7
votes
1answer
178 views

Quick Nurikabe Puzzle: $4$s

Nurikabe (taken from Nikoli) Fill in the cells with black under the following rules. You cannot fill in cells containing numbers. A number tells the number of continuous (adjacently) white ...
7
votes
3answers
270 views

Quick Ripple Effect Puzzle: $70$ Empty Cells

Ripple Effect (taken from Nikoli) The areas divided by bold lines are called "rooms". Fill in all empty cells with numbers under the following rules. Each room contains consecutive numbers ...
5
votes
1answer
648 views

Heyawake - why is this wrong solution

Dear people, Why does this particular android game not accept the solution on the right side? Rules in the app:
5
votes
1answer
179 views

Quick Moon-or-Sun Puzzles: 2x1-Dominoes and 1x1-Checkerboards

Moon-or-Sun (adapted from Nikoli) Draw a line to make a single loop. Lines pass through the centers of cells, horizontally, vertically, or turning. The loop never crosses itself, branches ...
14
votes
3answers
428 views

Instructionless: Sieve of Eratosthenes

This is an instructionless puzzle: work out the rules and then solve the main puzzle. An example and its unique solution have been given to you, as well as two failed solutions with errors marked. ...
7
votes
2answers
335 views

Quick Slitherlink Puzzles: KPK and 123

Slitherlink (taken from Nikoli) Connect adjacent dots with vertical or horizontal lines to make a single loop. The numbers indicate how many lines surround it, while empty cells may be ...
9
votes
2answers
345 views

Quick Tilepaint Puzzles: Corridors and Corners

Tilepaint (adapted from Nikoli) The areas enclosed by bold lines are called "Tiles" and color the tiles with the following rules. The cells of a tile must all be colored with black or left ...
13
votes
1answer
538 views

Sandwich Sudoku: First 12 digits of pi

Sandwich Sudoku, or "Between 1 and 9 Sudoku", is a variant of Sudoku. A YouTube channel introduced this variation. Rules: Standard Sudoku rules. Place numbers from 1 to 9 in every row, column, ...
20
votes
1answer
1k views

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 ...
7
votes
1answer
191 views

Heyacrazier: Big Three

This is a Heyacrazier puzzle, a variant of Heyacrazy. Rules of Heyacrazy: Shade some cells of the grid. Shaded cells cannot be orthogonally adjacent; unshaded cells must be orthogonally connected. ...
7
votes
2answers
352 views

Toroidal Heyacrazy: Rainstorm

This is a Toroidal Heyacrazy puzzle. Rules of Heyacrazy: Shade some cells of the grid. Shaded cells cannot be orthogonally adjacent; unshaded cells must be orthogonally connected. When the puzzle ...
6
votes
2answers
171 views

Yajilin minicubes: the Poppycock, the Balderdash, the Gobbledygook

These are three-dimensional yajilin puzzles. In each puzzle, the four squares depict the layers of a $4\times4\times4$ cube. Shade some cells on each layer. The numbered cells show how many shaded ...
8
votes
1answer
198 views

Heyacrazy: Dissection

This is a Heyacrazy puzzle. Rules of Heyacrazy: Shade some cells of the grid. Shaded cells cannot be orthogonally adjacent; unshaded cells must be orthogonally connected. When the puzzle is solved, ...
7
votes
1answer
425 views

Heyacrazy: Empty Space

This is a Heyacrazy puzzle. Rules of Heyacrazy: Shade some cells of the grid. Shaded cells cannot be orthogonally adjacent; unshaded cells must be orthogonally connected. When the puzzle is solved, ...
8
votes
2answers
274 views

Heyacrazy: No Diagonals

This is a Heyacrazy puzzle. Rules of Heyacrazy: Shade some cells of the grid. Shaded cells cannot be orthogonally adjacent; unshaded cells must be orthogonally connected. When the puzzle is solved, ...
11
votes
2answers
250 views

Heyacrazy: Careening

This is a Heyacrazy puzzle, designed at request of testsolvers of previous puzzles who wanted to see how longer diagonals would work. Rules of Heyacrazy: Shade some cells of the grid. Shaded cells ...
13
votes
2answers
705 views

Slitherlink Fillomino hybrid

This puzzle is a combination between a Slitherlink and a Fillomino. You should put a number in each square and draw a single closed loop over the grid such that the following properties are satisfied:...
9
votes
2answers
215 views

Heyacrazy: “LMI”

This is a Heyacrazy puzzle, originally constructed for a test for Logic Masters India. Rules of Heyacrazy: Shade some cells of the grid. Shaded cells cannot be orthogonally adjacent; unshaded cells ...
8
votes
1answer
210 views

Heyacrazy: Forks

This is a Heyacrazy puzzle. Rules of Heyacrazy: Shade some cells of the grid. Shaded cells cannot be orthogonally adjacent; unshaded cells must be orthogonally connected. When the puzzle is solved, ...
6
votes
1answer
138 views

Ambitious Puzzler's Masyu

Contrary to the lazy puzzler, the creator of this masyu is too ambitious that he adds not only one but two extra stones, so the puzzle is unsolvable. Finish his job for him by removing those ...
13
votes
1answer
795 views

Heyacrazy: Crosses

This is a Heyacrazy puzzle. Heyacrazy is an original genre, inspired by the "two border" rule of Heyawake and Heyawacky. Rules of Heyacrazy: Shade some cells of the grid. Shaded cells ...
16
votes
2answers
538 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;...
20
votes
2answers
2k views

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. ...

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