Mechanical puzzle

The game consists of a square divided into 14 parts, and the aim was to create different shapes from these pieces.

(see Ostomachion loculus Archimedius) In Iran "puzzle-locks" were made as early as the 17th century AD.

The company Richter from Rudolstadt began producing large amounts of Tangram-like puzzles of different shapes, the so-called "Anker-puzzles" in about 1891.

In 1893, Angelo John Lewis, using the pen name "Professor Hoffman", wrote a book called Puzzles; Old and New.

This book grew into a reference work for puzzle games and modern copies exist for those interested.

Furthermore, problems in which a number of pieces have to be arranged so as to fit into a (seemingly too small) box are also classed in this category.

Modern tools such as laser cutters allow the creation of complex two-dimensional puzzles made of wood or acrylic plastic.

In recent times this has become predominant and puzzles of extraordinarily decorative geometry have been designed.

For example, one puzzle consists of several discs in which angular sections of varying sizes are differently coloured.

Furthermore, puzzles consisting of several metal pieces linked together in some fashion are also considered part of this category.

The problem here lies in the shape of the interlocking pieces – the mating surfaces are tapered, and thus can only be removed in one direction.

There is a vast variety of opening mechanisms, such as hardly visible panels which need to be shifted, inclination mechanisms, magnetic locks, movable pins which need to be rotated into a certain position up and even time locks in which an object has to be held in a given position until a liquid has filled up a certain container.

The level of difficulty is usually assessed in terms of the number of moves required to remove the first piece from the initial puzzle.

The peak of this development is a puzzle in which the addition of a few pieces doubles the number of moves.

Prior to the 2003 publication of the RD Design Project by Owen, Charnley and Strickland, puzzles without right angles could not be efficiently analyzed by computers.

These kinds of puzzles often have extremely irregular components, which come together in a regular shape only at the last step.

[citation needed] Vexiers are a different sort of disentanglement puzzle – two or more metal wires, which have been intertwined, are to be untangled.

The common type, which connects the rings to a bar with cords (or loose metal equivalents) has a movement pattern identical to the Gray binary code, in which only one bit changes from one code word relative to its immediate neighbor.

The Chinese rings are associated with the tale that in the Middle Ages, knights would give these to their wives as a present, so that in their absence they may fill their time.

Tavern puzzles, made of steel, are based on forging exercises that provided good practice for blacksmith apprentices.

[8] Niels Bohr used disentanglement puzzles called Tangloids to demonstrate the properties of spin to his students.

The aim in this particular genre of puzzles is to fold a printed piece of paper in such a way as to obtain a target picture.

Hidden to the puzzler's eye, there is a small tubular conduit all the way through the grip and along the upper rim of the container up to the nozzle.

If one then blocks the opening at the upper end of the grip with one finger, it is possible to drink liquid from the container by sucking on the nozzle.

Another well known puzzle is one consisting of a cube made of two pieces interlocked in four places by seemingly inseparable links.

The games listed in this category are not strictly puzzles as such, as dexterity and endurance are of more importance here.

Often, the aim is to incline a box fitted with a transparent cover in just the right way as to cause one or more small balls to fall into holes.

With a varying orientation of the axis of rotation a variety of puzzles with the same basic shape can be created.