Tetris (Russian: Тетрис)[a] is a puzzle video game created in 1985 by Alexey Pajitnov, a Soviet software engineer.

In the 1980s, Pajitnov worked for the Dorodnitsyn Computing Center of the Academy of Sciences, where he programmed Tetris on the Electronika 60 and adapted it to the IBM PC with the help of Dmitry Pavlovsky and Vadim Gerasimov.

[14] He felt that the game would be needlessly complicated with the twelve different shape variations of pentominoes, so he scaled the concept down to tetrominoes, of which there are seven variants.

[10] Afterward, he programmed the basic mechanics, including the ability to flip tetrominoes as they fell in a vertical screen and the clearing of lines.

[27] Under Soviet law, intellectual rights were not protected, and the state-run organization Elektronorgtechnica (Elorg) had a monopoly on the import and export of software.

[41] Before releasing Tetris in the United States, the Spectrum HoloByte CEO, Gilman Louie, asked for an overhaul of the graphics and music.

[52] Nintendo was attracted to Tetris for its simplicity and established success on the Famicom, and considered porting it to their first handheld console, the Game Boy.

Discussions resulted the next day, when Stein and the Mirrorsoft manager Kevin Maxwell made an appointment with Elorg without consulting each other.

[63] Belikove believed that the rights to Tetris were only signed for computer systems;[64] in response, the present parties accused Rogers of illegal publication.

[63] Sympathetic to Rogers's plight, Belikov constructed a strategy to regain possession of the rights and obtain better commercial agreements.

[69] In response, the Mirrorsoft owner, Robert Maxwell, pressured the Soviet Union leader, Mikhail Gorbachev, to cancel the contract between Elorg and Nintendo.

[70] Despite the threats to Belikov, Elorg refused to concede and highlighted the financial advantages of their contract compared to those signed with Stein and Mirrorsoft.

[54] Judge Fern M. Smith rejected this argument and declared that Mirrorsoft and Spectrum HoloByte never received explicit authorization for marketing on consoles.

[54] The next day, Atari Games withdrew its NES version from sale, and thousands of cartridges remained unsold in its warehouses.

[54] In January 1990, Pajitnov was invited by Spectrum HoloByte to the Consumer Electronics Show, and he was immersed in American life for the first time.

[84] In 1991, with Rogers's help, Pajitnov and his family emigrated to Seattle, United States, where he worked as a freelance game designer.

Worried that Elorg, which became a private company under Belikov following the 1991 collapse of the Soviet Union,[86] would claim otherwise, Pajitnov recruited Rogers to secure his rights.

[106] Critics panned Tetris Worlds for its introduction of the easy spin mechanic, which allowed players to delay a piece's descent by continually rotating it.

[113] By December 2005, Electronic Arts (EA) started its acquisition of JAMDAT, Tetris had been consistently selling well on American carrier phones.

In an interview with VentureBeat in June 2014, Maya spoke of her desire to expand Tetris's brand, such as through merchandising, and keeping the game fresh.

[136][137] Tetris Effect was released on the PlayStation 4 on November 9, 2018,[138] and on Windows on July 23, 2019,[139] receiving widespread critical acclaim for its visuals and emotional impact.

Guinness World Records recognized Tetris as the most ported video game in history, with over 200 variants having appeared on over 65 different platforms as of October 2010.

[211] As part of the 2015 inaugural class, The Strong National Museum of Play inducted Tetris into the World Video Game Hall of Fame for its iconic nature.

[77] This success established Nintendo's dominant position in the handheld gaming market, setting a standard that competitors struggled to replicate.

[i] Tetris's cultural impact and recognition is widespread, as demonstrated by its continuing commercial success and representation in a vast array of media such as architecture, art, and merchandise.

For example, gameplay techniques such as "hypertapping" and "rolling" have been used to help competitors to maximize their scores beyond level 29, which was previously deemed impossible to complete due to its speed.

Interested in its potential psychological effects based on his experiences playing the game, Pokhilko distributed copies of Tetris to his colleagues at the Moscow Medical Center.

Pokhilko regretted his decision after constant gameplay impaired medical research and proceeded to destroy the distributed copies.

[250][251] In 1992, John Brzustowski at the University of British Columbia wrote a thesis reflecting on the question of whether or not one could theoretically play Tetris forever.

In 2001, a group of MIT researchers proved that for the "offline" version of Tetris (the player knows the complete sequence of pieces that will be dropped, i.e. there is no hidden information) the following objectives are NP-complete: Also, it is difficult to even approximately solve the first, second, and fourth problem.