Edge-matching puzzle

MacMahon Squares is the name given to a recreational math puzzle suggested by British mathematician Percy MacMahon, who published a treatise on edge-colouring of a variety of shapes in 1921.

[4] This particular puzzle uses 24 tiles consisting of all permutations of 3 colors for the edges of a square.

The objective of the game is to place the tiles into the grid in the proper position, completing this puzzle as quickly as possible.

The tiles cannot be rotated, and two can be placed next to each other only if the numbers on adjacent edges match.

[8][9] TetraVex was inspired by "the problem of tiling the plane" as described by Donald Knuth on page 382 of Volume 1: Fundamental Algorithms, the first book in his series The Art of Computer Programming.

It was named by Scott Ferguson, the development lead and an architect of the first version of Visual Basic, who wrote it for Windows Entertainment Pack 3.

[13] Serpentiles are the hexagonal tiles used in various abstract strategy games such as Psyche-Paths, Kaliko, and Tantrix.

[2] Current examples of commercial puzzles include the Dodek Duo, The Enigma, Mental Misery,[14] and Kadon Enterprises' range of three-dimensional edge-matching puzzles.

[15] The Carcassonne board game employs edge matching to constrain where its square tiles may be placed.

The original game has three types of edges: fields, roads and cities.