Top Questions

36 votes
4 answers
3k views
+250

Pythagorean pentagons

33 votes
7 answers
5k views

The Devil's Shell Game

14 votes
7 answers
3k views

Join six cities with roads

26 votes
6 answers
4k views

Find a chess position that can occur twice but not thrice in a single game

59 votes
1 answer
4k views

What should I call this poker hand with a straight?

11 votes
4 answers
3k views

Why, crystal ball? Why?

17 votes
4 answers
2k views

Magic: the Gathering – Scry-sort

11 votes
2 answers
5k views

Note to self: DO NOT FORGET!

15 votes
2 answers
2k views

Find the heaviest and the second heaviest coins

26 votes
1 answer
1k views

White is missing

20 votes
3 answers
1k views

Maze-Jigsaw Fusion

12 votes
4 answers
1k views

Design a magic trick

7 votes
3 answers
1k views

Continue a hard Loopy/Slitherlink puzzle without brute-force

18 votes
1 answer
1k views

Which heptomino is it obvious can't tile the plane?

18 votes
1 answer
2k views

A co--ection of images

19 votes
1 answer
921 views

Anyone Seen My Snorkel?

8 votes
3 answers
1k views

Walking in a random direction

20 votes
1 answer
781 views

Invalid Jigsaw Sudoku Layout

9 votes
4 answers
2k views

Four-cornered cow inheritance

19 votes
1 answer
1k views

An Amazing Configuration

17 votes
2 answers
659 views

An unusually tricky Galaxy

6 votes
3 answers
1k views

3x3 grid with no isosceles triangles of the same colour

4 votes
3 answers
1k views

Two 10-letter words consisting of 20 unique letters?

11 votes
4 answers
433 views

Pleasant Cuboids

6 votes
4 answers
702 views

How to get the numbers from 50 - 100 with the numbers 2, 0, 2, 4

9 votes
3 answers
863 views

Minimum number of flips needed to fully set a binary string

17 votes
1 answer
1k views

Puzzle from Pythagoras

12 votes
1 answer
2k views

Add rules to Minesweeper until you can start with nothing

11 votes
1 answer
1k views

Secret number magic trick

15 votes
1 answer
787 views

Numbers and Lines

6 votes
2 answers
972 views

BROWN + YELLOW = PURPLE [closed]

14 votes
1 answer
730 views

Meta-connect wall

9 votes
4 answers
852 views

Murder Mystery. Who is the killer?

17 votes
1 answer
920 views

Mercury in Centigrade

5 votes
2 answers
1k views

Football Pass Rate Paradox [closed]

11 votes
2 answers
640 views

Hail to Pnrfne!

13 votes
1 answer
726 views

Two Dimensional Connect Wall

6 votes
2 answers
338 views

Tiling a 5-by-5 bathroom with L-shaped triomino tiles

8 votes
2 answers
403 views

The shady puzzle that will keep you in the dark

11 votes
1 answer
625 views

Lines inside a shape

9 votes
2 answers
435 views

Unchained Again

4 votes
4 answers
403 views

How to make 2012 by using 2, 0, 1, 2?

16 votes
1 answer
768 views

Magical Spellchecker

11 votes
1 answer
966 views

Compare and you'll see they're not all the same (Keep them LARGE)

4 votes
2 answers
558 views

Brian Chen's Splash 2016 hunt #5

5 votes
1 answer
914 views

Anna and Boris play the Red Blue game

12 votes
1 answer
908 views

Sending the rookie shopping

7 votes
2 answers
690 views

Sny's Snabdec Puzzles


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