Puzzle
Encyclopedia
A puzzle is a problem
or enigma that tests the ingenuity
of the solver. In a basic puzzle, one is intended to put together pieces in a logical way in order to come up with the desired solution. Puzzles are often contrived as a form of entertainment, but they can also stem from serious mathematical or logistical problems — in such cases, their successful resolution can be a significant contribution to mathematical research
.
Solutions to puzzles may require recognizing pattern
s and creating a particular order. People with a high inductive reasoning aptitude
may be better at solving these puzzles than others. Puzzles based on the process of inquiry
and discovery to complete may be solved faster by those with good deduction
skills.
was created around 1760, when John Spilsbury, a British engraver and mapmaker, mounted a map on a sheet of wood that he then sawed around each individual country. Spilsbury used the product to aid in teaching geography. After catching on with the wider public, this remained the primary use of jigsaw puzzles until about 1820.
By the early 20th century, magazines and newspapers found that they could increase their daily subscriptions by publishing puzzle contest
s. Puzzles may also include letters, numbers, shapes, and riddles.
, Henry Dudeney
, Boris Kordemsky
and, more recently, David J. Bodycombe
, Will Shortz
, Lloyd King
and Martin Gardner
.
There are organizations and events catering to puzzle enthusiasts such as Ravenchase
, the International Puzzle Party, the World Puzzle Championship
and the National Puzzlers' League
. There are also Puzzlehunts like Maze of Games
or the Rittenhouse Chronicles.
The Rubik's Cube
and other combination puzzles
are toy
s based on puzzles that can be stimulating toys for kids and are a recreational activity for adults. Puzzles can be used to hide or obscure objects. A good example is a puzzle box
used to hide jewelry.
Game
s are often based on a puzzle. For example there are thousands of computer puzzle game
s and many letter game
s, word game
s and mathematical game
s which require solutions to puzzles as part of the gameplay. One of the most popular puzzle games is Tetris
.
A chess problem
is a puzzle that uses chess pieces on a chess board.
is a type of tour puzzle
. Other categories include construction puzzle
s, stick puzzle
s, tiling puzzle
s, transport puzzle
s, disentanglement puzzle
s, jigsaw puzzle
s, lock puzzle
s, folding puzzles, combination puzzles
and mechanical puzzle
s.
dates the word puzzle (as a verb
) to the end of the 16th century. That first documented use comes from a book called The Voyage of Robert Dudley
...to the West Indies, 1594–95, narrated by Capt. Wyatt, by himself, and by Abram Kendall, master (published circa 1595).
Their research, based on the "chronology of the words, and still more the consideration of their sense-history, seem[s] to make it clear that the verb came first, and that the noun was its derivative."
Problem
A problem is an obstacle, impediment, difficulty or challenge, or any situation that invites resolution; the resolution of which is recognized as a solution or contribution toward a known purpose or goal...
or enigma that tests the ingenuity
Ingenuity
Ingenuity refers to the process of applying ideas to solve problems or meet challenges. The process of figuring out how to cross a mountain stream using a fallen log, build an airplane from a sheet of paper, or start a new company in a foreign culture all involve the exercising of ingenuity...
of the solver. In a basic puzzle, one is intended to put together pieces in a logical way in order to come up with the desired solution. Puzzles are often contrived as a form of entertainment, but they can also stem from serious mathematical or logistical problems — in such cases, their successful resolution can be a significant contribution to mathematical research
Research
Research can be defined as the scientific search for knowledge, or as any systematic investigation, to establish novel facts, solve new or existing problems, prove new ideas, or develop new theories, usually using a scientific method...
.
Solutions to puzzles may require recognizing pattern
Pattern
A pattern, from the French patron, is a type of theme of recurring events or objects, sometimes referred to as elements of a set of objects.These elements repeat in a predictable manner...
s and creating a particular order. People with a high inductive reasoning aptitude
Inductive reasoning aptitude
Inductive reasoning is a measurable aptitude for how well a person can identify a pattern within a large amount of data. Measurement is generally done in a timed test by showing four pictures or words and asking the test taker to identify which of the pictures or words does not belong in the set....
may be better at solving these puzzles than others. Puzzles based on the process of inquiry
Inquiry
An inquiry is any process that has the aim of augmenting knowledge, resolving doubt, or solving a problem. A theory of inquiry is an account of the various types of inquiry and a treatment of the ways that each type of inquiry achieves its aim.-Deduction:...
and discovery to complete may be solved faster by those with good deduction
Deductive reasoning
Deductive reasoning, also called deductive logic, is reasoning which constructs or evaluates deductive arguments. Deductive arguments are attempts to show that a conclusion necessarily follows from a set of premises or hypothesis...
skills.
History
The first jigsaw puzzleJigsaw puzzle
A jigsaw puzzle is a tiling puzzle that requires the assembly of numerous small, often oddly shaped, interlocking and tessellating pieces.Each piece usually has a small part of a picture on it; when complete, a jigsaw puzzle produces a complete picture...
was created around 1760, when John Spilsbury, a British engraver and mapmaker, mounted a map on a sheet of wood that he then sawed around each individual country. Spilsbury used the product to aid in teaching geography. After catching on with the wider public, this remained the primary use of jigsaw puzzles until about 1820.
By the early 20th century, magazines and newspapers found that they could increase their daily subscriptions by publishing puzzle contest
Puzzle contest
Puzzle contests are popular competitions in which the objective is to solve a puzzle within a given time limit, and to obtain the best possible score among all players.-History:One of the earliest puzzle contests was held about 1910...
s. Puzzles may also include letters, numbers, shapes, and riddles.
Contemporary puzzles
A sample of notable puzzle authors includes Sam LoydSam Loyd
Samuel Loyd , born in Philadelphia and raised in New York, was an American chess player, chess composer, puzzle author, and recreational mathematician....
, Henry Dudeney
Henry Dudeney
Henry Ernest Dudeney was an English author and mathematician who specialised in logic puzzles and mathematical games. He is known as one of the country's foremost creators of puzzles...
, Boris Kordemsky
Boris Kordemsky
Boris A. Kordemsky was a Russian mathematician and educator. He is best known for his popular science books and mathematical puzzles. He is the author of over 70 books and popular mathematics articles.Kordemsky received Ph.D...
and, more recently, David J. Bodycombe
David J. Bodycombe
David J. Bodycombe is a puzzle author and games consultant. He is based in London, and his work is read by over 2 million people a day in the UK, and is syndicated to over 300 newspapers internationally...
, Will Shortz
Will Shortz
Will Shortz is an American puzzle creator and editor, and currently the crossword puzzle editor for The New York Times.-Early life and education:...
, Lloyd King
Lloyd King (puzzle designer)
Lloyd King is a puzzle designer, published author, and artist, based in Australia. King grew up in Hambleden, England, and became interested in puzzles after leaving school, eventually gaining enough confidence to write his own...
and Martin Gardner
Martin Gardner
Martin Gardner was an American mathematics and science writer specializing in recreational mathematics, but with interests encompassing micromagic, stage magic, literature , philosophy, scientific skepticism, and religion...
.
There are organizations and events catering to puzzle enthusiasts such as Ravenchase
Ravenchase
-History:Ravenchase was created in January 2001 by Joshua Czarda for his family. The company was founded in Richmond, Virginia and retains a corporate headquarters there.-Name:...
, the International Puzzle Party, the World Puzzle Championship
World Puzzle Championship
The World Puzzle Championship is an annual international puzzle competition run by the World Puzzle Federation. The first one was held in New York in 1992...
and the National Puzzlers' League
National Puzzlers' League
The National Puzzlers' League is a nonprofit organization focused on puzzling, primarily in the realm of word play and word games. Founded in 1883, it is the oldest puzzlers' organization in the world...
. There are also Puzzlehunts like Maze of Games
Maze of Games
The Maze of Games is one of America's largest annual puzzlehunts, and is held at the Gen Con and Origins gaming conventions. Started in 1995 as an offshoot of LIVE/WIRE, the Maze of Games has been the largest event at one or both of those conventions every year since. It is created by game...
or the Rittenhouse Chronicles.
The Rubik's Cube
Rubik's Cube
Rubik's Cube is a 3-D mechanical puzzle invented in 1974 by Hungarian sculptor and professor of architecture Ernő Rubik.Originally called the "Magic Cube", the puzzle was licensed by Rubik to be sold by Ideal Toy Corp. in 1980 and won the German Game of the Year special award for Best Puzzle that...
and other combination puzzles
Combination puzzles
A combination puzzle, also known as a sequential move puzzle, is a puzzle which consists of a set of pieces which can be manipulated into different combinations by a group of operations. The puzzle is solved by achieving a particular combination starting from a random combination...
are toy
Toy
A toy is any object that can be used for play. Toys are associated commonly with children and pets. Playing with toys is often thought to be an enjoyable means of training the young for life in human society. Different materials are used to make toys enjoyable and cuddly to both young and old...
s based on puzzles that can be stimulating toys for kids and are a recreational activity for adults. Puzzles can be used to hide or obscure objects. A good example is a puzzle box
Puzzle box
A puzzle box is a box that can only be opened through some obscure or complicated series of manipulations. Some puzzle boxes may require only a simple squeeze in the right spot, whereas others may require the subtle movement of several small parts, to open the box...
used to hide jewelry.
Game
Game
A game is structured playing, usually undertaken for enjoyment and sometimes used as an educational tool. Games are distinct from work, which is usually carried out for remuneration, and from art, which is more often an expression of aesthetic or ideological elements...
s are often based on a puzzle. For example there are thousands of computer puzzle game
Computer puzzle game
Puzzle video games are a genre of video games that emphasize puzzle solving. The types of puzzles to be solved can test many problem solving skills including logic, strategy, pattern recognition, sequence solving, and word completion....
s and many letter game
Letter game
A letter game involves the exchange of written letters, or e-mails, between two or more participants. The first player writes a letter in the voice of a newly created character; in this first letter, the writer should establish their own identity and that of their correspondent, should set the...
s, word game
Word game
Word games and puzzles are spoken or board games often designed to test ability with language or to explore its properties.Word games are generally engaged as a source of entertainment, but have been found to serve an educational purpose as well...
s and mathematical game
Mathematical game
A mathematical game is a multiplayer game whose rules, strategies, and outcomes can be studied and explained by mathematics. Examples of such games are Tic-tac-toe and Dots and Boxes, to name a couple. On the surface, a game need not seem mathematical or complicated to still be a mathematical game...
s which require solutions to puzzles as part of the gameplay. One of the most popular puzzle games is Tetris
Tetris
Tetris is a puzzle video game originally designed and programmed by Alexey Pajitnov in the Soviet Union. It was released on June 6, 1984, while he was working for the Dorodnicyn Computing Centre of the Academy of Science of the USSR in Moscow, Russian Soviet Federative Socialist Republic...
.
A chess problem
Chess problem
A chess problem, also called a chess composition, is a puzzle set by somebody using chess pieces on a chess board, that presents the solver with a particular task to be achieved. For instance, a position might be given with the instruction that White is to move first, and checkmate Black in two...
is a puzzle that uses chess pieces on a chess board.
Types of puzzles
The large number of puzzles that have been created can be divided into categories, for example a mazeMaze
A maze is a tour puzzle in the form of a complex branching passage through which the solver must find a route. In everyday speech, both maze and labyrinth denote a complex and confusing series of pathways, but technically the maze is distinguished from the labyrinth, as the labyrinth has a single...
is a type of tour puzzle
Tour puzzle
In tour puzzles the player of the puzzle makes a trip around a board using a token which represents a traveller....
. Other categories include construction puzzle
Construction puzzle
In a construction puzzle you have to build a technical contraption. This may be a static object or a mechanical object ....
s, stick puzzle
Stick puzzle
Stick puzzles use sets of 'polysticks' which have to be assembled into two- or three-dimensional configurations.Polysticks are configurations of joined or unjoined thin 'sticks'...
s, tiling puzzle
Tiling puzzle
Tiling puzzles are puzzles involving two-dimensional packing problems in which a number of flat shapes have to be assembled into a larger given shape without overlaps . Some tiling puzzles ask you to dissect a given shape first and then rearrange the pieces into another shape...
s, transport puzzle
Transport puzzle
Transport puzzles are logistical puzzles, which often represent real-life transport problems.-Description:In transport puzzles you move persons and/or objects through a given landscape. As in rearrangement puzzles, no piece is ever lost or added to the board...
s, disentanglement puzzle
Disentanglement puzzle
A disentanglement puzzle is a type of mechanical puzzle that involves disentangling one piece or set of pieces from another piece or set of pieces. The reverse problem of reassembling the puzzle can be as hard as—or even harder than—disentanglement...
s, jigsaw puzzle
Jigsaw puzzle
A jigsaw puzzle is a tiling puzzle that requires the assembly of numerous small, often oddly shaped, interlocking and tessellating pieces.Each piece usually has a small part of a picture on it; when complete, a jigsaw puzzle produces a complete picture...
s, lock puzzle
Lock puzzle
A lock puzzle is a type of mechanical puzzle. It consists of a lock with unusual or hidden mechanics. Such locks are sometimes called trick locks, because opening them is like performing a magic trick. A matching key may or may not be used in this trick....
s, folding puzzles, combination puzzles
Combination puzzles
A combination puzzle, also known as a sequential move puzzle, is a puzzle which consists of a set of pieces which can be manipulated into different combinations by a group of operations. The puzzle is solved by achieving a particular combination starting from a random combination...
and mechanical puzzle
Mechanical puzzle
A mechanical puzzle is a puzzle presented as a set of mechanically interlinked pieces.- History :The oldest known mechanical puzzle comes from Greece and appeared in the 3rd century BC....
s.
- Lateral thinking puzzles, which can be open ended and sometimes referred to as situation puzzleSituation puzzleSituation puzzles are often referred to as lateral thinking puzzles or "yes/no" puzzles.Situation puzzles are usually played in a group, with one person hosting the puzzle and the others asking questions which can only be answered with a "yes" or "no" answer...
s, or 'closed' lateral thinking puzzles which are designed to have only one correct and obvious answer. - Logic puzzleLogic puzzleA logic puzzle is a puzzle deriving from the mathematics field of deduction.-History:The logic puzzle was first produced by Charles Lutwidge Dodgson, who is better known under his pen name Lewis Carroll, the author of Alice's Adventures in Wonderland...
s using a chess board, such as Knight's TourKnight's tourThe knight's tour is a mathematical problem involving a knight on a chessboard. The knight is placed on the empty board and, moving according to the rules of chess, must visit each square exactly once. A knight's tour is called a closed tour if the knight ends on a square attacking the square from...
and Eight queens. - Mathematical problems such as the missing square puzzleMissing square puzzleThe missing square puzzle is an optical illusion used in mathematics classes to help students reason about geometrical figures. It depicts two arrangements of shapes, each of which apparently forms a 13×5 right-angled triangle, but one of which has a 1×1 hole in it.-Solution:The key to the puzzle...
. Many of these are "impossible puzzleImpossible PuzzleThe Impossible Puzzle, also named Sum and Product Puzzle is a puzzle called "impossible" because it seems to lack sufficient information for a solution. It was first published in 1969, and the name Impossible Puzzle was coined by Martin Gardner. The puzzle is solvable, though not easily...
s", such as the Seven Bridges of KönigsbergSeven Bridges of KönigsbergThe Seven Bridges of Königsberg is a historically notable problem in mathematics. Its negative resolution by Leonhard Euler in 1735 laid the foundations of graph theory and prefigured the idea of topology....
, Water, gas, and electricity and Three cups problemThree cups problemThe Three Cups problem is a mathematical puzzle that, in its most common form, cannot be solved. Starting with three cups, you place one of the cups upside down and the other two right-side up. The objective is to turn all cups right-side up in no more than six moves. You must turn over exactly two...
. See List of impossible puzzles. - Mathematical puzzleMathematical puzzleMathematical puzzles make up an integral part of recreational mathematics. They have specific rules as do multiplayer games, but they do not usually involve competition between two or more players. Instead, to solve such a puzzle, the solver must find a solution that satisfies the given conditions....
s - Mechanical puzzleMechanical puzzleA mechanical puzzle is a puzzle presented as a set of mechanically interlinked pieces.- History :The oldest known mechanical puzzle comes from Greece and appeared in the 3rd century BC....
s such as the Rubik's CubeRubik's CubeRubik's Cube is a 3-D mechanical puzzle invented in 1974 by Hungarian sculptor and professor of architecture Ernő Rubik.Originally called the "Magic Cube", the puzzle was licensed by Rubik to be sold by Ideal Toy Corp. in 1980 and won the German Game of the Year special award for Best Puzzle that...
, Soma cubeSoma cubeThe Soma cube is a solid dissection puzzle invented by Piet Hein in 1933 during a lecture on quantum mechanics conducted by Werner Heisenberg. Seven pieces made out of unit cubes must be assembled into a 3x3x3 cube...
, Tower of HanoiTower of HanoiThe Tower of Hanoi or Towers of Hanoi, also called the Tower of Brahma or Towers of Brahma, is a mathematical game or puzzle. It consists of three rods, and a number of disks of different sizes which can slide onto any rod...
, Burr puzzleBurr puzzleBurr puzzles are interlocking puzzles known in Europe and Asia since at least the 18th century. Traditionally they are made from wood, but some modern versions use plastic while those of collector's quality may be made from brass...
and impossible bottlesImpossible bottleAn impossible bottle is a type of mechanical puzzle. It is a bottle that has an object inside it that does not appear to fit through the mouth of the bottle. The objects inside authentic impossible bottles must always go through the neck. The glass cannot be cut or blown around the objects.The ship...
. - Meta-puzzleMeta-puzzleA metapuzzle is a puzzle that unites several puzzles that feed into it. For example, five puzzles that had the answers BLACK, HAMMER, FROST, KNIFE, and UNION would lead to the metapuzzle answer JACK, which combines with all of those words to make new words and phrases.A "meta-meta" unites several...
s are puzzles which unite or incorporate elements of other puzzles. It is often found in puzzlehuntPuzzlehuntA puzzlehunt is a puzzle game where teams compete to solve a series of puzzles at a particular site, in multiple sites and/or via the internet. Groups of puzzles in a puzzle hunt are often connected by a metapuzzle, leading to answers which combine into a final set of solutions...
s. - Paper-and-pencil puzzles such as Connect the dotsConnect the dotsConnect the dots, also known as dot to dot or join the dots is a form of puzzle containing a sequence of numbered dots. When a line is drawn connecting the dots the outline of an object is revealed. The puzzles often contain simple line art to enhance the image created or to assist in rendering a...
and Nonograms, and the Logic puzzles published by NikoliNikoliNikoli Co., Ltd. is a Japanese publisher that specializes in games and, especially, logic puzzles. Nikoli is also the nickname of a quarterly magazine issued by the company...
: SudokuSudokuis a logic-based, combinatorial number-placement puzzle. The objective is to fill a 9×9 grid with digits so that each column, each row, and each of the nine 3×3 sub-grids that compose the grid contains all of the digits from 1 to 9...
, Slitherlink, Kakuro, FillominoFillominoFillomino is a type of logic puzzle published by Nikoli. Other published titles for the puzzle include Allied Occupation. As of 2005, three books consisting entirely of Fillomino puzzles have been published by Nikoli.-Rules:...
, HashiwokakeroHashiwokakeroHashiwokakero is a type of logic puzzle published by Nikoli. It has also been published in English under the name Bridges or Chopsticks...
, HeyawakeHeyawakeHeyawake is a binary-determination logic puzzle published by Nikoli. As of 2011, four books consisting entirely of Heyawake puzzles have been published by Nikoli...
, HitoriHitoriHitori is a type of logic puzzle published by Nikoli.-Rules:Hitori is played with a grid of squares or cells, and each cell contains a number...
, Light UpLight UpLight Up , also called Akari, is a binary-determination logic puzzle published by Nikoli. As of 2011, three books consisting entirely of Light Up puzzles have been published by Nikoli.-Rules:...
, MasyuMasyuMasyu is a type of logic puzzle designed and published by Nikoli. The purpose of its creation was to present a puzzle that uses no numbers or letters and yet retains depth and aesthetics.-Rules:...
, Number LinkNumber LinkNumberlink is a type of logic puzzle involving finding paths to connect numbers in a grid.-Rules:The player has to pair up all the matching numbers on the grid with single continuous lines...
, NurikabeNurikabeNurikabe is a binary determination puzzle named for an invisible wall in Japanese folklore that blocks roads and delays foot travel...
, Ripple Effect, Shikaku and Kuromasu; see List of Nikoli puzzle types - Peg solitairePeg solitairePeg solitaire is a board game for one player involving movement of pegs on a board with holes. Some sets use marbles in a board with indentations. The game is known simply as Solitaire in the United Kingdom where the card games are called Patience...
- Picture puzzles, such as sliding puzzleSliding puzzleA sliding puzzle, sliding block puzzle, or sliding tile puzzle is a puzzle that challenges a player to slide usually flat pieces along certain routes to establish a certain end-configuration....
s like the fifteen puzzle; jigsawJigsaw puzzleA jigsaw puzzle is a tiling puzzle that requires the assembly of numerous small, often oddly shaped, interlocking and tessellating pieces.Each piece usually has a small part of a picture on it; when complete, a jigsaw puzzle produces a complete picture...
s and variants such as Puzz-3DPuzz-3DPuzz-3D is the brand name of three-dimensional jigsaw puzzles, manufactured by Hasbro . Unlike traditional puzzles which are composed of series of flat pieces with parts of an image on them, when put together, create a single unified image, the Puzz-3D series of puzzles are composed on plastic...
. - Puzzle video game
- SangakuSangakuSangaku or San Gaku are Japanese geometrical puzzles in Euclidean geometry on wooden tablets which were placed as offerings at Shinto shrines or Buddhist temples during the Edo period by members of all social classes.-History:The Sangaku were painted in color on wooden tablets and hung in the...
- SokobanSokobanis a type of transport puzzle, in which the player pushes boxes or crates around in a warehouse, trying to get them to storage locations. The puzzle is usually implemented as a video game....
- Spot the differenceSpot the differenceSpot the difference is a name given to a puzzle where two versions of an image are shown side by side, and the player has to find differences between them. Usually, the image on the left is the original, and the image on the right has the alternates...
- TangramTangramThe tangram is a dissection puzzle consisting of seven flat shapes, called tans, which are put together to form shapes. The objective of the puzzle is to form a specific shape using all seven pieces, which may not overlap...
- Word puzzles, including anagramAnagramAn anagram is a type of word play, the result of rearranging the letters of a word or phrase to produce a new word or phrase, using all the original letters exactly once; e.g., orchestra = carthorse, A decimal point = I'm a dot in place, Tom Marvolo Riddle = I am Lord Voldemort. Someone who...
s, crosswordCrosswordA crossword is a word puzzle that normally takes the form of a square or rectangular grid of white and shaded squares. The goal is to fill the white squares with letters, forming words or phrases, by solving clues which lead to the answers. In languages that are written left-to-right, the answer...
s, word searchWord searchA word search, word find, word seek, word sleuth or mystery word puzzle is a word game that is letters of a word in a grid, that usually has a rectangular or square shape. The objective of this puzzle is to find and mark all the words hidden inside the box. The words may be horizontally,...
es and cipherCipherIn cryptography, a cipher is an algorithm for performing encryption or decryption — a series of well-defined steps that can be followed as a procedure. An alternative, less common term is encipherment. In non-technical usage, a “cipher” is the same thing as a “code”; however, the concepts...
s.
Etymology
The 1989 edition of the Oxford English DictionaryOxford English Dictionary
The Oxford English Dictionary , published by the Oxford University Press, is the self-styled premier dictionary of the English language. Two fully bound print editions of the OED have been published under its current name, in 1928 and 1989. The first edition was published in twelve volumes , and...
dates the word puzzle (as a verb
Verb
A verb, from the Latin verbum meaning word, is a word that in syntax conveys an action , or a state of being . In the usual description of English, the basic form, with or without the particle to, is the infinitive...
) to the end of the 16th century. That first documented use comes from a book called The Voyage of Robert Dudley
Robert Dudley, styled Earl of Warwick
Sir Robert Dudley was an English explorer and cartographer. In 1594, he led an expedition to the West Indies, of which he wrote an account. The illegitimate son of Robert Dudley, 1st Earl of Leicester, he inherited the bulk of the Earl's estate in accordance with his father's will, including...
...to the West Indies, 1594–95, narrated by Capt. Wyatt, by himself, and by Abram Kendall, master (published circa 1595).
Their research, based on the "chronology of the words, and still more the consideration of their sense-history, seem[s] to make it clear that the verb came first, and that the noun was its derivative."
Related categories
- :Category:Puzzle books
- :Category:Puzzle designers
- :Category:Puzzle video games
See also
- Lateral thinking puzzle
- Puzzle jewelryPuzzle jewelryA piece of puzzle jewelry is a puzzle which can be worn by a person as jewelry.Usually these puzzles are fully mechanically functional and hence serve two purposes at once...
- RiddleRiddleA riddle is a statement or question or phrase having a double or veiled meaning, put forth as a puzzle to be solved. Riddles are of two types: enigmas, which are problems generally expressed in metaphorical or allegorical language that require ingenuity and careful thinking for their solution, and...
External links
- The Jerry Slocum Mechanical Puzzle Collection Presented by the Lilly Library of Indiana University.
- The puzzle archive of the rec.puzzles newsgroup