The seven tetrominoes.
A tetromino, officially known as a Tetrimino, is a polyomino made of four square blocks. The seven one-sided tetrominoes are I, O, T, S, Z, J, and L. In certain Tetris games, the colors of each tetromino vary.
The spelling "tetromino" is standard among mathematicians. The Tetris Company had preferred tetramino around 1999 and has used Tetrimino since 2001. TTC has trademarked the name Tetrimino and uses the initial uppercase T.
The basic tetrominoes[]
Each tetromino has a letter name and several alternative names. In most games other than Tetris for NES, Tetris & Dr. Mario, or black-and-white systems, each tetromino has a different color. However, before about 2001, these colors varied from product to product, making it difficult for people who play different games to discuss "the blue piece". Since then, the color schemes associated with SRS and TGM Rotation have dominated new games, and "the blue piece" is always J (see below).
The Tetris Company owns the copyright and trademark on all seven tetrominoes. The idea of tetrominoes is copyrighted to them. They were patented in 1996, but it expired two decades later. Another patent application was submitted in 2012. Tetris is still patented today, and the patent will expire in 2032.
I[]
- Main article: I-Tetrimino
This is the only tetromino that can clear four lines outside of cascade games.
Other names include straight, stick, strike, line, long bar, vav (or vov, waw), final nun, one, the cyan piece, the long skinny one, the slim jim, tetril, TGM-red, hot shot, long, slim dandy, the flashmaker, long boi, big poppa, Slenderman, thin lizzy, stack-em-up, Euclid's Arrow, four on the floor, George, hero, and a hot dog measuring 22 feet, 8 inches, which was made by Radford University's catering department.
  |
J[]
- Main article: J-Tetrimino
Other names include the blue piece, lowercase R, gamma, ghe, ge, inverse L, Va, reverse L, backwards L, left L, left periscope, left hook, led, left elbow, backwards (or reverse, inverse, etc)-orange, backwards daled (or dalet, daleth, dales), backwards resh (or reish), left gun and blue ricky.
 |
L[]
- Main article: L-Tetrimino
Other names include the orange piece, alpha, outverse J, seven, Vb, L2, right L, backwards J, TNT-magenta, right periscope, right hook, jed, right elbow, backwards-blue, daled (or dale, daleth, dales), resh (or reish), final kaf (or kof), final chaf (or chof, khof, khaf), reverse J, and orange ricky or right gun.
 |
O[]
- Main article: O-Tetrimino
This is the only tetromino where, when part of it is cleared, it is always split into dominoes.
Other names include square, block, samech, final mem, samekh, zero, sun, circle, the yellow piece, TNT-gray, smashboy, or box.
 |
S[]
- Main article: S-Tetrimino
Other names include the green piece, right turn, inverse skew, reverse Z, right skew, H, left N, Wa, saw, backwards-red, right dog, inverted Z, right kink, backward Z, reverse squiggly, backwards squiggly, right squiggly, mirror Z, right zigzag, TGM-magenta, right snake and Rhode Island Z.
 |
T[]
- Main article: T-Tetrimino
This tetromino is used for T-Spins.
Other names include The Tetris Block, Tetris logo, up-down-left-right, WASD, the purple/magenta piece, Y, Y' T turn, ted, triangle, arrow, small stairs, podium, pyramid, TNT-yellow, TGM-cyan, tire, tires, te, tee, t-piece and teewee.
 |
Z[]
- Main article: Z-Tetrimino
Other names include the red piece, left turn, outverse skew, right skew, S2, N, right N, Wb, zaw, S in mirror, backwards-green, lightning bolt, left dog, left kink, reversed S, squiggly, zigzag, left squiggly, left zigzag, TGM-green, left snake and Cleveland Z.
 |
Multimino[]
In The Next Tetris, Sticky mode of Tetris Worlds and Tetris Mania, Jewelry Master, and Alizarin Tetris, some tetrominoes are multiminoes, that is, the tetromino itself is divided into visible components. Though the tetromino is moved and rotated as a unit, once it locks, the components separate by colors and fall.
Puyo Puyo Tetris[]
In Puyo Puyo Tetris, each tetromino has its own personification. They serve as the crew of Starship Tetra, named Teto gou (テト号) in Japanese.[1][2]
Tee (Japanese: ティ, pronounced as Ti) is the youthful pretty boy captain of the group, resembling Puyo Puyo's Schezo and Maguro. He wields a chakram-like disc and references spinning a lot, due to his being based on the T tetromino (and the mechanic of T-Spins).
O (オー, pronounced as Oo) is the ship's mascot that supervises the ship, consisting of a yellow sphere with arms and a face, sitting on a cloud, with two O-tetromino pigtails for hair, resembling Puyo Puyo's Carbuncle. He is based on the O tetromino.
Ess (Japanese: エス, pronounced as Esu) is a space Sci-Fi Southern Belle type girl, with a sharp, abusive tongue. She believes Zed to be her 'Papa', but it is really Ex (an 'extra' Tetris character based on the X pentomino) who is her biological father. She resembles Puyo Puyo's Raffine and Strawberryna, along with Rhythm Thief R's Maria, and wields a parasol as a weapon. She is based on the S tetromino.
Zed (Japanese: ゼット, pronounced as Zetto) is a big robot with a red Z-tetromino emblazoned on his front, who serves as the Starship's housekeeper and chef, and who is the adoptive father of Ess. It is based on the Z tetromino.
Jay and Elle (Japanese: ジェイ&エル, pronounced as Jei & Eru) are a set of twins who delight in causing mischief, much to the chagrin of Ai. They are treated as a single character gameplay-wise, and are based on the J and L tetrominoes, respectively- with Elle being the only Starship Tetra crew member whose color scheme is not based on the tetromino she's based on, as the L tetromino is generally orange, while Elle herself is a combination of pink and brownish-red.
Ai (Japanese: アイ, pronounced as Ai) is the chief engineer of the Starship Tetra, a tall anthropomorphic dog who is normally a knowledgeable gentleman, but breaks into frightened whimpers at the drop of a hat. He resembles Puyo Puyo's Risukuma, and wields a plumb bob as a weapon. He is based on the I tetromino.
There is also the X pentomino, which is named Ex. He is the Keeper of Dimensions.
