A curated list of great puzzles
This repository hosts a curated collection of quality puzzles of different nature (mostly logical or mathematical). You can immediately start by choosing one of the puzzles below. You are strongly encouraged to contribute to this list, but please read our guidelines below. Please also send suggestions, corrections or clarifications.
The following list tries to describe the type of puzzle that we are looking for. These rules are highly subjective. They might make more sense if you have already solved a few of the puzzles above.
Puzzles should be fun to think about. We like puzzles which can be solved by out-of-the-box thinking. We like puzzles which can be solved by logical reasoning. We don't like puzzles which can be solved by repetitive, dreary calculations or brute forcing.
Solutions should be satisfying. We like puzzles with Eureka moments where it is suddenly obvious that you found the solution, sometimes without even checking. We like puzzles with surprising or counter-intuitive solutions. We don't like puzzles where you go "meeh.. seriously?" if you see the solution.
Puzzles should be self-contained. Puzzles should be clearly stated. If additional questions arise while solving the puzzle, they should be irrelevant to the solution.
Zebra puzzle. This can be solved by putting a lot of work into it. While this can be great fun, it is similar to solving a Sudoko - it involves long, repetitive work.
String girdling Earth. While this is a nice question with a counter-intuitive answer, it is just a simple math exercise that doesn't require puzzle-solving skills.