Edge-matching puzzle
An edge-matching puzzle is a type of tiling puzzle involving tiling an area with polygons whose edges are distinguished with colours or patterns, in such a way that the edges of adjacent tiles match.
Edge-matching puzzles are known to be NP-complete, and capable of conversion to and from equivalent jigsaw puzzles and polyomino packing puzzle.
The first edge-matching puzzles were patented in the U.S. by E. L. Thurston in 1892.
Current examples of commercial edge-matching puzzles include the Eternity II puzzle, TetraVex, Dodek Duo, Kadon Enterprises' range of edge-matching puzzles, and the Edge Match Puzzles iPhone app.
