Tetris Guideline

The Tetris Guideline is the current specification that The Tetris Company enforces for making all new (2001 and later) Tetris game products alike in form. 
The 3 main modes (Marathon, 40 Lines, and Ultra) will adhere to the design guideline more closely than other modes. These modes adhere to the specifications listed in the Tetris Variant Concepts.
To download the guideline in its entirety, click here.
== List of rules (as of 2009) ==
*Playfield is 10×40, where rows above 20 are hidden or obstructed by the field frame to trick the player into thinking it's 10×20. In 2002 Guideline, it could be at least 22 height.
**If hardware permits it, a few pixels of row 21 will be visible.
*Tetrimino colors are as follows.
**Cyan I
**Yellow O
**Purple T
**Green S
**Red Z
**Blue J
**Orange L
**In versions that use monochrome screens, or when hardware limitations disallow all colors to be used, the Tetriminos should have distinct hues and patterns to differentiate themselves.
*Tetromino start locations
**The I and O spawn in the middle columns
**The rest spawn in the left-middle columns
**The tetriminoes spawn horizontally with J, L and T spawning flat-side first.
**Spawn above playfield, row 21 for I, and 21/22 for all other tetriminoes.
**Immediately drop one space if no existing Block is in its path
*Initial rotation and movement
**Super Rotation System/Standard Rotation System (SRS) specifies tetrimino rotation.
*Standard mappings for console and handheld gamepads:
**Up, Down, Left, Right on D-pad perform locking hard drop, non-locking soft drop (except first frame locking in some games), left shift, and right shift respectively.
**A (or its equivalent thereof) rotates 90 degrees counterclockwise, and B (or its equivalent thereof) rotates 90 degrees clockwise.
**Shoulder buttons and X (or its equivalent thereof) use hold.
*Standard mappings for computer keyboards:
**Up arrow and X are to rotate 90° clockwise.
**Space to hard drop.
**Shift and C are to hold.
**Ctrl and Z are to rotate 90° counterclockwise.
**Esc and F1 are to pause.
**Left, right, and down arrows are the same as on the console.
**Number pad controls:
***0 is to hold.
***8, 4, 6, and 2 are hard drop, left shift, right shift, and soft drop respectively.
***1, 5, and 9 are to rotate 90° clockwise.
***3 and 7 are to rotate 90° counterclockwise.
*Standard mappings for cellphones:
**Arrow keys are the same as on the console.
***If the cellphone does not have an OK button on the directional pad, the up arrow is to rotate clockwise.
**OK to rotate clockwise.
**2, 4, 6, and 8 are the same as up, down, left, and right respectively. (2 will always hard drop.)
**0 is to hold.
**3, 5, 7, and # rotate clockwise.
**1, 9, and * rotate counterclockwise.
**The left soft key is to pause.
***If the cellphone does not have softkeys, the menu button (if separate from the OK button) is to pause.
*Standard mappings for remotes:
**Number pad is the same as on a cellphone.
**Arrow keys are the same as on the console.
**OK is to rotate.
**Channel + and Menu are to pause.
**If the remote does not have certain buttons, one in the same area as the one omitted is used.
*So-called 7-bag Random Generator (also called "random bag" or "7 system")
*"Hold piece": The player can press a button to send the falling tetrimino to the hold box, and any tetrimino that had been in the hold box moves to the top of the screen and begins falling. Hold cannot be used again until after the piece locks down. Games on platforms with fewer than eight usable buttons (such as the version on iPod) may skip this feature. The combination of hold piece and Random Generator would appear to allow the player to play forever. It must be enabled by default.
*Must have sound effects on by default, on rotation, movement, landing on surface, touching a wall, locking, line clear and game over.
*Game must have ghost piece function enabled by default.
*Terms used in the "help" section:
**"Tetriminos" (the capital T is required), as opposed to "tetrominoes", "tetrads" or "pieces".
**Letter names, as opposed to "square", "stick", etc.
*Designated soft drop speed. Details vary between guideline versions.
*Player may only level up by clearing lines or performing T-Spins. Required lines depends on the game.
**May use fixed-goal or variable-goal.
**Fixed goal is 10 lines
**Variable goal is 5 times the level number.
**The line values for variable-goal levels are as follows:
*** Single = 1 line
*** Double = 3 lines
*** Triple = 5 lines
*** Tetris = 8 lines
*The game must use a variant of Roger Dean's Tetris logo, although this was true from around 2000 - before the guidelines emerged.
**The logo may not have its t-tetrimino split into 4 minoes.
**The logo may not be sheared or skewed.
**The logo must be 2D.
*Game must include a song called Korobeiniki. This must be the default song.
*Uses half second lock delay.
*The player tops out when a piece is spawned overlapping at least one block (block out), or a piece locks completely above the visible portion of the playfield (lock out).
*Must have 1 to 6 next pieces.
**6 is the recommended number of next pieces.
*Recognition and rewarding of T-spin moves. Conditions vary between guideline versions.
**2005 / 2009: 3-corner T
**2006: 3-corner T no kick
*Multiplayer and Arcade variations must have 15 moves/rotations before lock.
*Mini T-spin is when one of the minoes next to pointing side is empty, or holes were made without using the triple kick.
*Rewarding of Back to Back chains. (Tetris / T-spin)Recognition method depends on the game.
*Marathon mode must have 15 levels.
*40 line mode (called sprint or 40 lines)
*2 or 3 minute timed mode (called ultra)
*Speed curve must be the same as Tetris Worlds.
*Game must use a scoring system described here.
*Game must count down from 3 after you press start, and after you resume a paused game.
*Game must have this notice when the game starts (XXXX is the year the game was created):
 Tetris © 1985~XXXX Tetris Holding.
 Tetris logos, Tetris theme song and Tetriminos are trademarks of Tetris Holding.
 The Tetris trade dress is owned by Tetris Holding.
 Licensed to The Tetris Company.
 Tetris Game Design by Alexey Pajitnov.
 Tetris Logo Design by Roger Dean.
 All Rights Reserved.
Although Guideline-compliant games share many traits, they also have differences in many aspects as well. There are a few instances where a game will break a trait which is shared by all other games thought to be compliant. Examples of this include the lack of the hold function and the T-spin's ability to start and continue Back-to-Back chains in iPod Tetris, and the inverted rotation button layout of TGM3 and TGM ACE (or Kiwamemichi, depending on interpretation). No explanations have been given for the reasons of these games' deviations.
Certain games, such as Tetris Online (Japan) and the handheld electronic games by Radica Games defy the guidelines despite having "Authentic Tetris Game" labels. No explanations have been given for the reasons of this.
== Guideline Versions ==
2002, 2005, 2006, and 2009 are the four known guideline versions. 2002 guideline games have been released as late as 2005. Both 2005 and 2006 guideline games have been released as late as 2007.
So far, the first confirmed guideline 2005 games (TGM ACE) has been released in December 2005, while the first confirmed guideline 2006 game (Tetris: New Century, although iPod Tetris released earlier behaves similarly) was released in September 2006. It was previously conjectured that each guideline version is released somewhere in the second half of the year. However, the 2009 Tetris Guideline was released in March 2009, so this conjecture is invalidated. It is not known when the first confirmed 2009 guideline game was released.
While many games have no publicly visible indication of the guideline version by the developer or publisher, some games have had their exact guideline versions made clear by them. They are listed in the Guideline compliant game differences page.
The guideline also includes a "Borg Clause," which states that all variants featured in guideline games are owned by TTC. Therefore, all of the following aspects are owned by TTC:
* Cascade gravity (since 2001)
* Bag randomizer (since 1999)
* Weighted bag randomizer (since 2001)
* TGM grading (since 1998)
* History 4 / 6 rolls (since 1998 (4) and 2005 (6))
* IHS/IRS
* Initial spawn orientation (up)
* Ghost piece
* T-Spin
== See also ==
*Guideline compliant game differences
*Tetris Worlds, Tetris Deluxe, and Tetris Zone, considered by many to be the "reference" implementations of the Guideline at the respective times of the games' releases.
**Some of the variants in Tetris Worlds are listed in the Tetris Variant Concepts.
*Tetris DS, another popular game that is compliant with the Guideline. Some of its variants are also listed in the "Tetris Variant Concepts" portion of the guideline..
== References ==
*Edge magazine's interview with Henk Rogers Henk first reveals the existence of the Guideline (dead link).
*Planet GameCube: Tetris from the Top: An interview with Henk Rogers that reveals some aspects of the Guideline (dead link).
*EA Tetris product page, with official names for some Guideline features (dead link, now redirects to the EA game list)
Category:General Information