Most Popular

1500 questions
34
votes
3 answers

How can I procedurally generate Sokoban puzzles?

How can Sokoban puzzles be procedurally generated with a computer program, guaranteeing at least one solution? A simple algorithm might be: {n} times place a "target" square and a box on the square end until {puzzle is done (?)} move a…
Doorknob
  • 4,657
  • 5
  • 35
  • 50
34
votes
9 answers

Find the composite poison in the wine bottles

You are the ruler of a medieval kingdom who loves throwing parties. The courtier who tried to poison one of your wine bottles last time was furious to learn that you managed to identify which bottle he had poisoned out of 1,000 with just ten…
user88
34
votes
2 answers

What bases make this number square?

For what values of $x$ is the number $121$ a square in base $x$? This is a very easy question, but I still think it's pretty fun. Perhaps it's something to pass on to younger people who are taking algebra.
blakeoft
  • 1,519
  • 11
  • 13
34
votes
6 answers

The Devil's Shell Game

Inspired by the Skull Game in StoneStory RPG. You make a deal with the Devil. You are granted your deepest desire, in exchange, eventually, for your eternal soul. Every year, on your birthday, he arrives at midnight to play a game. A fiery glow…
Hand-E-Food
  • 745
  • 5
  • 8
34
votes
1 answer

`print("Hello, World!")`

Build HELLO. Only rotations, no reflections.
Sunny Lu
  • 2,844
  • 3
  • 33
34
votes
1 answer

A number sequence in disguise

What number should replace the question mark? Explain why. 10051005 51005 1001005 10010010055 …
Prim3numbah
  • 33,595
  • 4
  • 19
  • 171
34
votes
9 answers

Two Sheriffs and Eavesdroppers

Two sheriffs are working on a case to find one culprit. There were initially 8 suspects; through independent work, each sheriff has narrowed this down to a list of 2. Because they are good sheriffs, they can be sure that both of their lists contain…
Mike Earnest
  • 32,336
  • 6
  • 92
  • 237
34
votes
1 answer

Puzzle with a wrong solution

I finished this word puzzle, but I don't think I solved it correctly. Can you help me fix it?
IAmLucidNonsense
  • 3,382
  • 8
  • 36
34
votes
1 answer

What is wrong with these puzzles?

I think teh puzzles on this site are too hard. I can’t figure out hardly none of them. The ones that look easy seem to get closed??? Can someone tell the reason? Here are some examples of puzzles that I could actually solve, but keep getting…
Amoz
  • 26,817
  • 2
  • 63
  • 159
34
votes
3 answers

,,sɹǝʇʇǝnoɹᴉԀ,,

The answer to this puzzle is a number. For the color blind, here are the colors of all characters in the…
sarsaparilla
  • 6,090
  • 18
  • 55
33
votes
2 answers

Find the hidden word (Harry Potter theme)

Bouncing bulbs are jumping all around the greenhouse. Can you help sort them out and figure out the hidden word? (Note: the answer is something from Harry Potter)
DenverCoder1
  • 10,472
  • 20
  • 89
33
votes
4 answers

The Devil's Brother

The 1933 movie "The Devil's Brother" (also known under the title "Fra Diavolo") takes place in the Northern Italy of the early 18th century. Stan Laurel and Oliver Hardy play the fierce robbers Stanlio and Ollio. They manage to steal 100 gold coins…
Gamow
  • 45,573
  • 10
  • 147
  • 381
33
votes
1 answer

How to get a bowl with one liter of water

You are given a rectangular bowl with size 5 x 30 x 40 cm and you should put exactly one liter of water into the bowl. You go to your kitchen, where you can put the water directly into the bowl from the water tap. You have no other tool beside the…
ThomasL
  • 12,167
  • 3
  • 24
  • 100
33
votes
1 answer

Twelve Labours - Conclusion

This puzzle is the FINAL part of the ‘Twelve Labours’ series, and contains spoilers for previous instalments, which can be found here: Prologue | 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11 | 12 With all twelve labours finally completed,…
Stiv
  • 140,467
  • 11
  • 495
  • 752
33
votes
1 answer

The first Density™ Puzzle!

Welcome to the very first puzzle in a new series! It's all about (hopefully) exploring new ways of creating puzzles, as densely as possible. If you'd like to create your own Density™ puzzle, the rules are as follows: 1. The resolution of the grid…
Dmihawk
  • 4,496
  • 1
  • 16
  • 37