Pajitnov, A. (1985). Tetris [Video game]. Academy of Sciences of the Soviet Union.

Tetris, created in 1985 by Soviet software engineer Alexey Pajitnov, is a pioneering puzzle video game that has achieved global acclaim. The game challenges players to manipulate falling tetrominoes—geometric shapes composed of four squares—by rotating and positioning them to form complete horizontal lines without gaps. Successfully completing a line clears it from the playfield, awarding points and providing space for additional pieces. As gameplay progresses, the speed at which tetrominoes descend increases, intensifying the challenge and requiring quicker decision-making and spatial awareness.

The game's simplicity and engaging mechanics have led to its adaptation across more than 65 platforms, earning it a Guinness World Record for the most ported video game. Its widespread availability and enduring popularity have resulted in over 500 million copies sold, making Tetris one of the best-selling video games in history. The game's iconic status was further cemented when it was bundled with Nintendo's Game Boy in 1989, significantly contributing to the handheld console's success and introducing Tetris to a broader audience.

Beyond its addictive gameplay, Tetris has been the subject of psychological studies, notably concerning the "Tetris effect," where individuals devote so much time to an activity that it begins to pattern their thoughts, mental images, and dreams. Additionally, the game's development and distribution history involve complex legal battles over licensing rights during the late 1980s, reflecting the geopolitical tensions of the era. In 1996, the rights to Tetris reverted to Pajitnov, who, alongside Henk Rogers, founded The Tetris Company to manage and license the Tetris brand.

Tetris's cultural impact is profound, influencing various media and inspiring numerous sequels and spin-offs. Its elegant design and universal appeal continue to captivate players worldwide, solidifying its legacy as a timeless classic in the video game industry.