Last updated 8 Mar 2014
Optical Illusions. Some great optical illusions.
The following are selections of my favorite puzzles, arranged by category. They contain only "best-of-class" type puzzles, meaning there are not many repeats of the same type and difficulty of puzzle. There are also no riddles, or trick answers. I never liked them.
Logic Puzzles. These puzzles require no mathematics at all, but only straightforward thinking. They begin at elementary school level and get tougher.
Math Puzzles. These puzzles some mathematics, but the first ones don't need much. They begin at elementary school level and get tougher.
Science Puzzles. These puzzles require knowledge of at least high school physics.
Word Puzzles. Various kinds of word puzzles.
Jacob's Missing Descendant
A logic puzzle which may be both the world's oldest as well as best puzzle!