The Mammoth Book of Codeword Puzzles is a truly bumper collection of these hugely popular puzzles - also known as codewords, cipher crosswords and cipher word puzzles. There are also some fun variations in the form of dropouts, keywords, coded quotes and long diversions.In a codeword puzzle, each grid is made up of numbered squares, with each number corresponding to a letter of the alphabet. A few letters are given, but the rest must be discovered by using logic and word power to crack the code. HOURS OF STIMULATING PUZZLE FUN!