7 articles
Eternity II puzzle
Eternity II (Eternity2) is an edge-matching puzzle launched in 2007, whose 256 square pieces must fill a 16×16 grid; its $2,000,000 prize expired unclaimed at the end of 2010.
Polyomino
Polyomino: edge-connected shapes made of unit squares, named by Solomon W. Golomb in 1953. Includes dominoes through pentominoes, Tetris tetrominoes, NP-complete tiling, and enumeration up to n=59.
Soma cube
Soma cube: 3D dissection puzzle invented by Piet Hein (1933 or 1936) during a Heisenberg lecture; seven polycube pieces (one tricube, six tetracubes, 27 cubes) form a 3x3x3 cube with 240 distinct solutions.
Spalone
Spalone is a 2012 solitaire puzzle by Cameron Browne for the Shibumi set, the solitaire version of Spanic: draw white, black, or red balls at random and stack them into a 30-ball pyramid.
Spirograph
Spirograph: geometric drawing toy invented by Denys Fisher, shown at Nuremberg 1965, US launch by Kenner 1967; draws hypotrochoids and epitrochoids with toothed wheels and rings.
Tangram
Tangram (七巧板) is a Chinese dissection puzzle of seven tans from a square, rearranged into silhouettes without overlap; 13 convex solutions, 19th-century Western spread, spatial-reasoning and AI benchmark uses.
Tetromino
Tetromino: a polyomino of four squares joined edge to edge; 5 free, 7 one-sided (the Tetris set), 19 fixed shapes. Named by Solomon Golomb's 1953 polyomino system; basis of Tetris.