Unanswered Questions
431 questions with no upvoted or accepted answers
56
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0
answers
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Unsolved Mysteries: D'Agapeyeff cipher
The D'Agapeyeff cipher is an as-yet unbroken cipher that appears in the first edition of "Codes and Ciphers", an elementary book on cryptography published by the cryptographer Alexander D'...
- 2,158
36
votes
0
answers
4k
views
Noita Eye Glyphs
A puzzle found hidden between the background layers of the computer game Noita. The puzzle has not been solved since it was added to the game in October of 2020.
It is made of thousands of eye images, ...
- 7,138
27
votes
0
answers
2k
views
Is there a move-efficient way to rotate the center pieces on the Octo-Star?
I'm looking for a more efficient algorithm to rotate the center column of the Octo-Star puzzle 45 degrees.
The situation below occurs when four properly-oriented edges are next to each other, ...
- 63
26
votes
0
answers
2k
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Decrypting the Key: "Phage is Spreading.."
I've been trying to solve this puzzle called "Phage is Spreading.."
...
- 10.9k
22
votes
0
answers
2k
views
REALLY important days in history
@Z. Dailey asks a mathematical puzzle Important days in history... and to come! with a series of dates in years 1973, 1978, 1983, 1992, 2005.
My puzzle asks the question: What is the previous date in ...
- 197
20
votes
0
answers
1k
views
Alternate, complex potions puzzle from HP fanfic
A long narrow room. The entrance is blocked by purple flame, the path onward blocked by black flame. On a table, the only thing in the room, are two dozen potions in opaque bottles. Half green glass, ...
- 201
18
votes
0
answers
789
views
Determining the meaning of a challenge coin
I saw this rather cool looking challenge coin the other day, and I was wondering what the associated binary on the back of it means, as it isn't standard ASCII.
In plaintext:
...
- 10.9k
17
votes
0
answers
315
views
Edge Removal Game
There is a complete undirected graph with n nodes (n > 1). Alice and Bob take turns removing one edge from the graph, with Alice going first. The player whose move causes any node to become ...
- 2,572
15
votes
0
answers
3k
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Crack the pigeon code
Can you crack this message? It was discovered in a chimney in 2012 attached to a carrier pigeon and was most likely sent during the D-day invasions. The GCHQ was not able to crack it, even after ...
- 139
15
votes
0
answers
2k
views
14
votes
0
answers
692
views
Qubes: Oh, For the Love Of
TL;DR: This is a mixture between a tribute/spin-off puzzle and an attempt at a new puzzle type, greatly inspired by the notorious arcade game, Q*bert, published originally by Gottlieb Amusement Games. ...
- 813
14
votes
0
answers
915
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?
- 123
13
votes
0
answers
393
views
The Snake and the Hunter
The Snake and the Hunter is a game for two players who play in two rounds interchanging the roles of snake and hunter. The game is played in a rectangular grid of points, say 6×6. In both rounds the ...
- 19.7k
13
votes
0
answers
544
views
Quantum tic tac toe strategy
Most of us learn tic tac toe early in our life. Also, it is easy to find an optimal strategy for playing.
How about Quantum tic tac toe? What is the optimal strategy for playing it?
Rules
On a ...
- 16.5k
12
votes
0
answers
1k
views
Hidden message in rap text II: "Ya, a ray 'ave july joy!"
This puzzle is inspired by this one by @LukasRotter. Hopefully you don't mind me using similar (well, basically the same) format as yours, Mr. Rotter! ;)
The same rapper released another teaser for ...
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