Tetris originated in Russia around 1985 and was never patented, at the time intellectual property rights were not established in then communist Russia for private individuals.
History
The original author of Tetris was Alexey Pajitnov (Pazhitnov), assisted by Dmitry Pavlovsky and Vadim Gerasimov. Computer engineers, Alexey Pajitnov and Dmitry Pavlovsky worked together at the Computer Center of the Russian Academy of Sciences.
Alexey Pajitnov had already published and sold several psychology based games. Dmitry Pavlovsky had written computer games for mainframes. High school student, Vadim Gerasimov (only sixteen at the time) had just written a directory encryption program for MS DOS when he introduced to the pair. It was Alexey Pajitnov who first conceived of the game Tetris based on another game of his called Genetic Engineering. Alexey Pajitnov and Henk Rogers later founded the Tetris Company.
Development of Tetris
The name Tetris comes from the Greek work tetra or "four". Tetris is a computer puzzle game in which various shapes each made of four squares are falling down a well. The user turns the pieces around and moves them left or right in order to arrange them on top of the other. When a solid line of squares is made from edge to edge, the line dissolves and all the pieces move down by one square. When the lines dissolve points are won, when the well fills up the game ends. Players work hard to keep the well as empty as possible, but as the game progresses the pieces fall faster and faster making that harder.