Paradoxes and paperfolding, moebius variations and mnemonics, fallacies, brain-teasers, magic squares, topological curiosities, probability and parlor tricks, and a variety of ancient and new games and problems, from polyominoes, nim, hex and the Tower of Hanoi to four-dimensional ticktacktoe. Together with mathematical commentaries by Mr. Gardner and addenda from readers of Scientific American. Plus bibliographies and, of course, solutions.