Questions tagged [construction]
A puzzle that requires an example to be built that fits certain criteria.
159 questions
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Undecidable Checkmate
While playing chess, I had a momentary dizzy spell which erased most of my short-term memory. I knew only the current position, and that I was playing White, and that all play so far had been legal, ...
- 2,585
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4
answers
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The Worst Possible Chess Move
Bad, even very bad chess moves are nothing out of the ordinary. Every single player will have had their fair share of stupid blunders like hanging a queen in an otherwise completely winning position. ...
- 11k
18
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3
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How many computers can be connected at once?
Netwalk (and other names) is a puzzle game with randomly generated "networks" consisting of computers (nodes), a source node, and connectors (either a straight through pipe, a right-angled ...
- 424
11
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1
answer
608
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Most symmetrical tangram
We discovered a new toy store near our house, and my daughter and I were very excited to check it out. We found a curious puzzle there and brought it home with us. After googling about it a bit, I ...
- 20.4k
12
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2
answers
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Stretch an elastic band around three nails so that it relaxes when any nail is removed
Three nails are placed on a wooden board. You are given an elastic band. Can you stretch it around the nails so that it relaxes when any of the three nails is removed? The band is relaxed when it does ...
- 20.4k
9
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3
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How to cut a tetrahedron in half using only a pencil and a knife?
You are given a pencil, a knife, and an object, and you are asked to cut the object in half using only the tools provided to you. For example, if the object is a square or a cube, you can mark the cut ...
- 20.4k
18
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1
answer
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Polygon whose sides are not completely visible from a point
Can you construct a polygon (not necessarily convex, but definitely not self-intersecting) such that there is an internal point from which no side of the polygon is completely visible? If yes, what is ...
- 20.4k
7
votes
1
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Dividing both the interior and the boundary of a square into equal parts using polyominos
We want to cover an m×m square with n non-overlapping axis-parallel polyominos such that both the interior and the boundary of the square are divided into n equal areas and n equal lengths, ...
- 20.4k
16
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3
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Are there other LEGO Duplo track layouts with two trains that trigger all the switches indefinitely?
My daughter has a LEGO Duplo railway set that she loves to play with. Here are some basic track elements in the set (I made the figures myself): the red element is a circular arc of 30°, the green ...
- 20.4k
14
votes
8
answers
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Snow White and the Seven Rooks on Dark Squares
With the white queen on a light-coloured square of your choosing, can you place 7 rooks on the dark squares of the chessboard so that no piece attacks another?
In the above Lichess illustration (with ...
- 85.4k
6
votes
4
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Minimum number of clues for a Find-the-stars puzzle
Previously I posted collections of my Find-the-stars puzzles here, here and here.
This post is different.
You are asked to create a puzzle.
Find-the-stars rules:
A Find-the-stars puzzle is played on ...
- 32.1k
12
votes
3
answers
716
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How many IKEA train track layouts with self-intersections?
Recently, I got an IKEA LILLABO train set for my daughter. It has twelve curved segments, each is 1/8th of a circle of radius 1, two straight segments of length 1, and a bridge of length 2 (in top ...
- 20.4k
5
votes
1
answer
479
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Covering a Rubik's Cube Pattern with Pentominoes
Given a Rubik's Cube pattern:
And using each of the following 12 pentominoes at least once:
Can you cover entirely the Rubik's Cube?
The answer is obviously yes!
However, given that the Rubik's Cube ...
- 7,968
-1
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2
answers
321
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Chess - Amazons - Magnus Carlen vs Gukesh 2025 Norway
Parts of this puzzle are taken from this nice puzzle of @Will.Octagon.Gibson.
An Amazon is a fairy chess piece that can move like a queen or a knight.
In this famous game at Norway in 2025, ...
- 7,968
13
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3
answers
1k
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All Europe Countries Segmented
This puzzle is an attempt of improvement to my previous closed and poorly described puzzle.
You are given the following map of Europe:
And the following list of 50 Europe countries:
Albania
Andorra
...
- 7,968