Tetris
Soviet software engineer Alexey Pajitnov invented Tetris in Moscow in 1984.
While working at the Dorodnitsyn Computing Centre of the Soviet Academy of Sciences, Pajitnov drew inspiration from pentomino tabletop puzzles to develop a computer program for testing hardware. He named the program Tetris by combining the Greek prefix tetra with tennis.
Lacking graphical capabilities on his Electronika 60 terminal, Pajitnov rendered the falling shapes using text brackets. High school student Vadim Gerasimov soon ported the game to MS-DOS for the IBM PC, adding color, a scoring system, and disk-sharing capabilities that spread the game across Eastern Europe.
Because Pajitnov created the software on state-owned equipment, copyright automatically belonged to the Soviet government through its trade agency ELORG. Dutch video game publisher Henk Rogers eventually secured global handheld rights directly in Moscow, leading to the landmark 1989 Nintendo Game Boy release that turned Tetris into an international phenomenon.
A Soviet researcher testing hardware created a simple falling-block puzzle that crossed Cold War boundaries to become one of history's defining video games.