What do you call the falling pieces in Tetris?...

Apparently, it depends on who you ask.

Alexey Pajitnov

The creator of Tetris himself prefers this term.

“I've loved puzzles ever since I was a child, especially pentominoes. You could get three of these geometric games for a rouble in Moscow toyshops. In June 1984, it occurred to me that they might be a good basis for a computer game. But having the 12 pentomino pieces rotating in real time seemed too complicated, so I scaled it down to tetrominoes, of which there are seven. Also, the Electronika 60, the Russian computer I originally wrote Tetris for, didn't have proper graphics, just a monitor that could display text, so I used letters to form the playing pieces.”
— The Guardian (2 Jun. 2014)

Geometers

Like dominoes and pentominoes, tetrominoes are just one of the many classes of polyominoes.

“A polyomino is a plane geometric figure formed by joining one or more equal squares edge to edge. It is a polyform whose cells are squares. It may be regarded as a finite subset of the regular square tiling with a connected interior.”
— Wikipedia

Tetris Wiki

The wiki created to “compile every Tetris detail known to mankind” prefers this term.

“Tetrominoes fall from above one at a time. In Tetris, a player positions falling Tetrominoes so that they fill up an entire Line. The player must sort them such that he or she forms continuous horizontal line clears, which will then clear, and the above tetrominoes will fall. Frequently, clearing multiple lines simultaneously will benefit the player. For example, clearing four such lines yield a tetris. As the game progresses, the tetrominoes fall faster, making things more difficult.”
— Tetris Wiki

Demaine, Hohenberger & Liben-Nowell (Tetris is Hard, Even to Approximate)

— Erik D. Demaine, Susan Hohenberger and David Liben-Nowell

Andy Wilton (Advanced Computer Entertainment magazine) [Feb. 1988]

Vadim Gerasimov

The 16-year-old intern who helped bring Alexey Pajitnov’s ideas to life prefers this term.

“At one of our meetings Pajitnov told Pavlovsky and me about his new idea of tetramino falling into a rectangular glass and piling up at the bottom. He believed the game might be successful. Shortly after discussing the idea Pajitnov made a prototype for Electronica 60, then I ported it to the PC using our development system. Pajitnov and I kept adding features to the program for a couple of years.

“The game name Tetris was purely Alexey's idea. The word is a combination of tetramino and tennis. I thought it sounded a bit strange in Russian, but Pajitnov insisted on giving the game this name.”
— Vadim Gerasimov

Lighted Tetris (Radica) [2004]

Radica Tetris [2006]

The Tetris Company

Drafted in 2001, the Tetris Guideline provides immense detail about all the subtle rules underlying the game, including this term to describe the dropping pieces.

“The Tetris game requires players to strategically rotate, move, and drop a procession of Tetriminos that fall into the rectangular Matrix at increasing speeds. Players attempt to clear as many lines as possible by completing horizontal rows of blocks without empty space, but if the Tetriminos surpass the Skyline the game is over! It might sound simple, but strategy and speed can go a long way! Are YOU up for the challenge?”
— The Tetris Company

Tetris Worlds (PlayStation 2) [2001]

Tetris DS (Nintendo DS) [2006]

PlayTV Legends Family Tetris (Radica) [2006]

Tetris Link (board game, Techno Source) [2011]

Tetris: The Card Game (Fundex Games) [2011]

Tetris: Axis (Nintendo 3DS) [2011]

Puyo Puyo Tetris [2014]

Nintendo Power

Nintendo Power magazine volume 8 from 1989 introduced readers to the pack-in game for an upcoming handheld system.

Nintendo Power magazine volume 9 from 1989 featured NES Tetris. It directed readers to get “Tetrisized” via “mind-bending madness, from Russia with love.”

Howard and Nester

Originally bundled with Nintendo Power magazine volume 10 from 1990, the Strategy Guide An Adventure in Tetris features the characters Howard and Nester in clay Tetris block form and a detailed description of the game, including this term.

In the final panel, the Tetris King refers to the “Tetrisized” Howard and Nester using an abbreviated version of this term.

Scientists

Like monads, dyads, and triads, tetrads are just one of the many classes of polyads, groups of some number of items.

“The blood moon marked the beginning of a tetrad—four consecutive and complete lunar eclipses occurring at six-month intervals—which some see as a prophecy.”
— USA TODAY (21 Sep. 2017)

Tetris (Amiga) [1987]

TETЯIS (arcade, Atari) [1988]

The Games Machine (magazine) [Mar. 1988]

Donald B. Trivette (PC Magazine) [17 May 1988]

Dennis Lynch (Chicago Tribune) [10 Jun. 1988]

“Glasnost has arrived in the world of computer gaming in the form of Tetris, an amazingly addictive program that comes from Russia with love. It's a game so good that you won't be able to say nyet to it.

“Remember the video game called Breakout, where the object was to destroy a series of walls made of bricks? In Tetris you also rack up points for making walls disappear, but first you have to build those walls. As variously shaped blocks drop from the top of your computer screen, you use cursor keys or a joystick to maneuver the blocks to fall into a similarly shaped space at the bottom. Whenever a row is completely filled it disappears, giving you more room to maneuver. The game continues until you run out of room to put the blocks.

“Tetris is so simple to learn that you'll know all the rules five minutes after opening the box. But it's so intriguing to play that once you've started you'll be spending many hours in front of the computer screen—so many that you'll begin to wonder if Tetris isn't really part of a diabolical plot hatched in the Evil Empire to lower worker productivity in the United States.”

— Dennis Lynch

Owen W. Linzmayer (A+ Magazine) [Dec. 1988]

Tetris (NES, Nintendo) [1989]

Tetris (Game Boy) [1989]

The description in the instruction booklet is nearly identical to its NES counterpart.

TETЯIS (Commodore 64/128, Mastertronic) [1989]

Flash Point (arcade, Sega) [1989]

The data sheet assures arcade owners that the machine will even milk coins out of highly skilled players.

Tetris (board game, Milton Bradley) [1989]

Computer and Video Games (magazine) [Mar. 1989]

Paul Rand (Computer and Video Games magazine) [Nov. 1989]

Bloxeed (arcade, Sega) [1990]

As its name suggests, the arcade game Bloxeed uses this term.

Tetris Plus (arcade, Jaleco) [1990]

Zero 3 (magazine) [Jan. 1990]

Princess Lana (Captain N - Totally Tetrisized) [5 Oct. 1991]

One of the characters in Totally Tetrisized, a Season 3 episode of Captain N: The Game Master, makes use of this term.

“Huh! The blocks are falling! Look out!”
— Princess Lana

David Sears (COMPUTE!) [Aug. 1992]

Daniel Whitehead (Amiga Computing magazine) [Sep. 1992]

Allen R. Myerson (The New York Times) [4 Jul. 1993]

“The personal computer revolution was supposed to transform the office into a high-tech, high-efficiency web of concentration.

“Maybe. But it's also turning it into an electronic sandbox. Computer games, bulletin boards and electronic message systems are creating countless new ways to goof off.

“At General Motors, the desk-bound fly the Starship Enterprise into battle against the Klingons. Pacifists play Tetris, rotating blocks to fill patterns.”

— Allen R. Myerson

Steven Levy (The New York Times) [18 Jul. 1993]

“Nintendo Game Boy hand-held units are frequent attachments to traveling executives who spend hours in first-class compartments dropping Tetris blocks.”

— Steven Levy

Tetris 2 (NES) [1993]

Hailed as a “tougher Tetris challenge”, Tetris 2 introduced a color-matching mechanic similar to Dr. Mario and 3 new “Falling Block” types that break apart upon landing.

Tetris & Dr. Mario (SNES) [1994]

Tetris Blast (Game Boy) [1996]

3-D Tetris (Virtual Boy) [1996]

Tetris Plus (Game Boy) [1997]

Tetris DX (Game Boy Color) [1998]

Sega Tetris (arcade) [1998]

Chris Kohler (Wired) [4 Jun. 2009]

“What made Tetris different? The game was graphically elegant and easy to grok: To play, you arranged seven different kinds of falling blocks into a tower without letting them pile too high. The game was so straightforward and simple that anybody could pick it up, yet as play progressed Tetris became more and more challenging.”

— Chris Kohler

Ed Yong (Discover Magazine) [10 Nov. 2010]

“Tetris, it seems, makes an ideal choice for that. To position its rotating blocks, players need good visuospatial skills—they need to see, focus on, and act upon the positions of different objects, all at high speed. These are the same sort of mental abilities that provide the foundations for flashback images.”

— Ed Yong

Tom Stafford (BBC) [23 Oct. 2012]

“The other reason why Tetris works so well is that each unfinished task only appears at the same time as its potential solution—those blocks continuously fall from the sky, each one a problem and a potential solution. Tetris is a simple visual world, and solutions can immediately be tried out using the five control keys (move left, move right, rotate left, rotate right and drop—of course). Studies of Tetris players show that people prefer to rotate the blocks to see if they'll fit, rather than think about if they'll fit. Either method would work, of course, but Tetris creates a world where action is quicker than thought—and this is part of the key to why it is so absorbing. Unlike so much of life, Tetris makes an immediate connection between our insight into how we might solve a problem and the means to begin acting on it.”

— Tom Stafford

Peter Hartlaub (SFGATE) [5 Jun. 2014]

“Simplicity is its hallmark. Players stack one of seven differently shaped blocks, gaining points as the blocks blocks blocks blocks
(Ed. note: The reporter just stopped writing midsentence here. We suspect he went to play Tetris.)”

— Peter Hartlaub

Hani Shawwa (CBS NEWS) [6 Jun. 2014]

“Invented in Russia in 1984 by scientist Alexey Pajitnov, the game involves connecting a series of falling, differently shaped blocks to make complete rows. Failure to find a home for the cascading tiles means game over.”

— Hani Shawwa

Laurence Dodds (The Telegraph) [7 Jul. 2015]

“The game is simple. Coloured blocks of varying shape fall from the top of the screen, piling up at the bottom. If you can arrange them in neat lines without leaving any gaps, they flash, disappear, and you are awarded points. But scoring these points makes the blocks fall faster, and before you know it they are piling up to the top of the screen—at which point you lose. This, as its legions of fans will have recognised, is the compulsively addictive computer game, Tetris.

“In Tetris, you spend the whole game trying to build a perfect wall so you can watch it vanish. Perhaps only the Soviet Union could have produced a game of such stunning perversity. But then, how different really is it from a white-collar day job where you must deal with whatever lands on your desk faster than it can accumulate? ‘If Tetris has taught me anything about life,’ runs one internet proverb, ‘it’s that errors pile up and accomplishments disappear.’”

— Laurence Dodds

Steven Poole (The Spectator) [8 Oct. 2016]

Ken McMahon (Commodore User magazine) [Dec. 1987]

Zzap!64 magazine [Jan. 1988]

David Bishop (Computer and Video Games magazine) [Feb. 1988]

Advanced Computer Entertainment (magazine) [Apr. 1988]

David and Robin Minnick (COMPUTE!'s GAZETTE) [Jun. 1988]

Kathryn Daniels (Amiga Computing magazine) [Jun. 1988]

Lynne Weatherman (COMPUTE!) [Jul. 1988]

Advanced Computer Entertainment (magazine) [Jul. 1988]

Tetris (Tandy) [1988]

Tetris (NES, Tengen) [1989]

Nick Kelly (Commodore User Amiga-64 magazine) [Mar. 1989]

Guy Wright (Amiga World) [Apr. 1989]

Carolyn Cushman (Antic's Amiga Plus magazine) [Apr - May 1989]

Commodore User Amiga-64 magazine [May 1989]

Gordon Houghton and Paul Rand (Zzap!64 magazine) [Jun. 1989]

Computer and Video Game magazine [Jun. 1989]

Electronic Gaming Monthly [Dec. 1989]

Brooke A. Masters (The Washington Post) [10 Apr. 1990]

“The screen is filled with spinning shapes—squares, L's and Z's. They drift, then plummet to the ground. Neat rows form as human hands drive this alphabet of falling snow.

“This is Tetris—one of the hottest-selling video and computer games around.

“Forget guns and explosions. Tetris is about geometry, not war. Players manipulate the sinking shapes to fill in holes and form complete rows. If a level fills, it disappears, and all the other pieces drop a notch. When holes remain, the pieces stack higher and higher until they fill the screen.

“The game is simple, but strangely compelling.”

— Brooke A. Masters

Eugene Lacey (Advanced Computer Entertainment magazine) [Aug. 1990]

Steve White (Amiga Action magazine) [Aug. 1992]

Gary Whitta (The One Amiga magazine) [Aug. 1992]

Tony Dillon (Commodore User magazine) [Aug. 1992]

Jeffrey Goldsmith (Wired) [01 May 1994]

The Tetris effect is a biochemical, reductionistic metaphor, if you will, for curiosity, invention, the creative urge. To fit shapes together is to organize, to build, to make deals, to fix, to understand, to fold sheets. All of our mental activities are analogous, each as potentially addictive as the next.

— Jeffrey Goldsmith

Steve Lohrdec (The New York Times) [22 Dec. 1997]

“The Russian-born Mr. Pajitnov, who joined Microsoft last year, introduced millions of people to a potent blend of skill, concentration and compulsion found in the best computer games. He designed Tetris, perhaps the most irresistibly habit-forming computer game ever. Tetris, an elegantly simple puzzle game requiring the player to reorder cascading geometric shapes, sold 40 million copies on every format from personal computers to Nintendo hand-held video-game players.”

— Steve Lohrdec

Alex Bickham (Planet Game Boy) [Summer 1999]

Catherine Greenman (The New York Times) [27 Apr. 2000]

“Tetris was developed 15 years ago by Alexey Pajitnov, a Russian mathematician, and involves manipulating four shapes (each made up of four blocks) as they fall down the screen to form horizontal rows, which disappear when they are complete. The object of the game is to keep clearing out rows as the falling blocks speed up.”

— Catherine Greenman

TETРИС (TETRIS) The Soviet Challenge (Apple IIGS) [1988]

Gordon Hamlett (Your Amiga magazine) [Jun - Jul 1988]

inCider Magazine Editors [Oct. 1988]

David D. Thornburg (inCider Magazine) [May 1990]

Ed Ricketts (Amiga Format magazine) [Sep. 1992]

Tetrisphere (NINTENDO⁶⁴) [1997]

Unlike traditional Tetris, the goal in Tetrisphere is to remove bricks by forcing three of the same type of piece to touch.

The New Tetris (NINTENDO⁶⁴) [1999]

Magical Tetris Challenge (NINTENDO⁶⁴) [1999]

Kristin Leutwyler (Scientific American) [16 Oct. 2000]

“Seventeen of these 27 subjects reported seeing the same images during hypnagogic sleep—namely falling geometric pieces that, if placed properly, rack up points in Tetris. And, interestingly, most of these reports occurred after the second night of the study. This delay suggests to the researchers that the need to learn may in part prod the brain into dreaming. ‘It's as if the brain needs more time or more play before it decides, okay, this is something that I really need to deal with at sleep onset,’ Stickgold says.”

— Kristin Leutwyler

Damo Spendel (Amiga Mania magazine) [Oct. 1992]

Matthew Mientka (Medical Daily) [6 Jun. 2014]

“With simple graphics from the dot-matrix era of computing, Tetris challenges the player to tessellate multi-shaped bricks falling steadily downward, forever risking the asymmetry of game over. The vintage game tickles the brain’s basic pleasure in solving mental problems such as those presented in this ‘world of perpetual uncompleted tasks,’ said Tom Stafford of the University of Sheffield in the United Kingdom.”

— Matthew Mientka

Peter H. Lewis (The New York Times) [29 Jan. 1988]

“In Tetris, geometric objects in the shapes of T's, L's, I's and squares fall down from the top of the computer screen, and the player must rapidly rotate and assemble them into solid rows. Players say it is surprisingly addictive.”

— Peter H. Lewis

Matt Peckham (TIME) [6 Jun. 2014]

“Thirty years ago today, a little game about dropping geometrically strange thingamajigs—originally clusters of punctuation marks—into neat, lookalike rows kicked off on a wild journey that led it (and it’s Russian creator, Alexey Pajitnov) out of a metamorphosing Soviet Union to the United States, and from ‘blockbuster’ sales of 2 million already by 1988 to over 425 million paid mobile downloads today.”

— Matt Peckham