Alexey Pajitnov / Academy Of Sciences, Moscow, 1984 / USSR / Selected by Warren Spector

Credited with creating the dynamic puzzle game genre – which inspired the likes of “Bejeweled,” which in turn helped establish “casual games” as a market category – “Tetris” was designed in 1984 by computer programmer Alexey Pajitnov at the Academy of Sciences in Soviet-era Moscow. The game is a case study of what’s possible in videogame design: it’s dynamic, it’s procedurally generated, and it gives control of the game to the player. It’s also a study in elegant design. Using only four differently shaped pieces, which the player maneuvers through space to form uniform blocks, Pajitnov created an experience with an incalculable number of outcomes. Though first released commercially by Mirrorsoft and Spectrum Holobyte in 1988, “Tetris” did not enter mainstream consciousness until Nintendo released it with the launch of the Game Boy in 1989. Part of its success is its ability to transcend platform limitations; the game is equally popular on the PC, console and handheld