A logic puzzle is a puzzle deriving from the mathematics field of deduction.

This branch was produced by Charles Lutwidge Dodgson, who is better known under his pseudonym Lewis Carroll, the author of Alice's Adventures in Wonderland. In his book The Game of Logic he introduced a game to solve problems such as

• some games are fun
• every puzzle is a game

Q: Are all puzzles fun?

A: Not necessarily.

Puzzles like this, where we are given a list of premises and asked what can be deduced from them, are known as syllogisms. Of course, this example is trivial. Dodgson goes on to construct much more complex puzzles consisting of up to 8 premises.

In the second half of the 20th century mathematician Raymond M. Smullyan has continued and expanded the branch of logic puzzles with books such as The Lady or the Tiger?, To Mock a Mockingbird and Alice in Puzzle-Land. He popularized the "knights and knaves" puzzles, which involve knights, who always tell the truth, and knaves, who always lie.

There are also logic puzzles that are completely non-verbal in nature. Some popular forms include Sudoku and Unisol, which involves using deduction to correctly place numbers in a grid; the nonogram, also called "Paint by Numbers", which involves using deduction to correctly fill in a grid with black-and-white squares to produce a picture; and logic mazes, which involve using deduction to figure out the rules of a maze.

Logic grid puzzles

Another form of logic puzzle, popular among puzzle enthusiasts and available in large magazines dedicated to the subject, is a format in which the set-up to a scenario is given, as well as the object (for example, determine who brought what dog to a dog show, and what breed each dog was), certain clues are given ("neither Misty nor Rex is the German Shepherd"), and then the reader fills out a matrix with the clues and attempts to deduce the solution. These are often referred to as "logic grid" puzzles. The most famous example may be the so-called Zebra Puzzle, which asks the question Who Owned the Zebra?.

See also

• :Category:Logic puzzles, a list of different logic puzzles
• List of puzzle video games

External links

• Online puzzles category аt Open Directory Project