Nine-Colour Cube other, there is no parity constraint; all of the above positions are attainable. The full number is therefore: Out of the 268 240 896 000 possible configurations, there are 80 that represent a solved puzzle. These solutions fall into three categories: Nine-Colour Cube The Nine-Colour Cube ("see below" for other names) is a cubic twisty puzzle. It was invented in 2005 by Milan Vodicka and mass-produced by Meffert's seven years later. Mechanically, the puzzle is identical to the Rubik's Cube; however, unlike the Rubik's Cube, which only has 6 different colours, the Nine-Colour Cube has 9 colours, with the individual
Soma cube their faces, such that at least one inside corner is formed. There is one combination of three cubes that satisfies this condition, and six combinations of four cubes that satisfy this condition, of which two are mirror images of each other (see Chirality). Thus, 3 + (6 × 4) is 27, which is exactly the number of cells in a 3×3×3 cube. The Soma cube was analyzed in detail by John Horton Conway on September 1958 in Mathematical Games column in "Scientific American", and the book "Winning Ways for your Mathematical Plays" also contains a detailed analysis of the Soma