We have updated our Privacy Policy Please take a moment to review it. By continuing to use this site, you agree to the terms of our updated Privacy Policy.

With this brain-teasing new collection of tantalizing puzzles and top-grade problems, Nathan Haselbauer, mastermind behind the test for the world’s most intelligent person, throws open an irresistible challenge to all.

The puzzles vary from math and logic problems to word games, with the emphasis on clarity of presentation and elegance of answer. Covering a broad spread of difficulty, they range from the surprisingly easy to a level of difficulty that will fox even the world’s most devious minds. Although each puzzle is capable of being solved in just a few minutes, this is a puzzle collection like no other that will stretch your brainpower to its limits.