TGM legend

Standard and common acronyms [[Image:50%.png]]

 * TGM : Tetris The Grand Master, used to refer to the series in general.
 * TGM/TGM1 :  Tetris The Grand Master, the first game of the series.
 * TAP/TGM2 : Tetris The Absolute Grand Master 2 +.
 * Ti/TGM3 : Tetris The Grand Master 3 Terror Instinct.
 * ACE/TGMA : Tetris The Grand Master Ace.
 * ARS : Arika Rotation System.
 * SRS : Super Rotation System.
 * IRS : Initial Rotation System.
 * IHS :</tt> Initial Hold System.
 * GRS :</tt> Grade Recognition System.
 * TLS :</tt> Temporary Landing System.
 * TTC :</tt> The Tetris Company.
 * BPS :</tt> Bullet Proof Software / Blue Planet Software.

Basic Terms [[Image:25%.png]]
Appellation standards for Tetris games vary, especially with TGM. To avoid confusion, we list here the basic terms used most frequently when in context with the TGM series. All terms are not yet listed, and the order is still not fixed.

Block [[Image:25%.png]]
A block is a single square grid cell. From this 1x1 cell makes components such as tetrominoes, garbage, etc.

Tetramino [[Image:75%.png]]
In Japanese or even in general common usage, the word "block" can refer to both a tetromino or single grid cell. Another annoying fact is that there are several syntax for the same word:
 * Tetramino (commonly used in Japan, used less often in the USA)
 * Tetromino (most frequent in math journals and scholarly resources)
 * Tetrimino (TTC term)

To avoid any confusion we will always use the word "Tetramino" instead of "block," "piece," "tetra," etc. when in the context of TGM.

Four blocks arranged into a shape make the tetramino. Seven different tetraminos exist, each one with a specific color. TGM inherits its tetramino colors and rotation rules from Sega's 1988 arcade version of Tetris. But with the release of Ti and ACE, SRS has been added, which means different initial orientations and tetramino colors. It is also a common usage to refering to them by a single letter instead of by color :

Tetrion [[Image:25%.png]]
Sometimes called the "outfit frame" or more simply the "box that surround the game". This term is rarely used in general conversation, but this is the official designation from TTC. We only refer to it to avoid confusion between the playfield and the game.

Playfield [[Image:25%.png]]
The playfield is surrounded by the tetrion. The standard size is fixed to a grid of ten blocks width and of twenty blocks height. In fact, the playfield's usable space is twenty-two blocks high. Two "vanished lines" are available on the upper part of the Tetrion. If you stack a Tetramino on these two lines, the blocks remaining will not be visible until a few lines are cleared.

Stack [[Image:25%.png]]
Each time a tetramino is locked in the playfield, it becomes part of the stack. Building a perfect stack is the very essence of all Tetris games, which means stacking each tetramino in a clean manner without making holes. Several other Tetris games pose stacking challenges, and TGM has its own, such as the '>' shape secret grade.

Garbage [[Image:25%.png]]
Garbage is also part of the stack and is the consequence of your VS opponent's multiple cleared lines. Garbage appears from the bottom of the playfield and pushes up the current stack. Generally, garbage blocks consist of a row of 9 tetraminos, leaving a hole in a row (the hole position determination is actually unclear). The garbage lines count is directly dependant of the opponent cleared rows count. Garbage also appears in Ti Shirase mode from level 500 to level 999 at regular intervals. The garbage lines, in this case, are generated by copying the bottom-most line.

Row [[Image:25%.png]]
Filling a line without a hole will produce a row, also simply called a "cleared line." Rows are always deleted before the next tetramino distribution. The stack above the cleared row drops down to the row equivalent. There exists four different row denominations :
 * Single : One row.
 * Double : Two rows.
 * Triple : Three rows.
 * Tetris : Four rows.

There is no explicit denomination when you clear more rows (eg. Big mode).

Tetris [[Image:25%.png]]
Erasing four rows with the I tetramino rewards a Tetris.

Combo [[Image:25%.png]]
Uninterrupted Rows sequence from a distributed tetramino continuation. Usually, a combo rewards more points, especially for rows which follow a Tetris (e.g. TGM1 & TAP).

Bravo [[Image:25%.png]]
When you succeed to clear all playfield stack content after a row, leaving nothing. You are rewarded with a "Bravo" pop up screen (a.k.a. "All clear"). On TGM1 and TAP, you earn extra bonus points by multiplying current combo by four.

Frame [[Image:25%.png]]
Before becoming a game, Tetris is basically a program. The frame is the shortest time indice in TGM. The game is running to a fixed value of 60 frames per seconds. A lot of Technical concept analysis use the frame as scale value instead of seconds.

Here is the basic of the gameplay process instruction order in ONE frame (draft) :
 * 1) Input read
 * 2) Gameplay process
 * 3) Rotation
 * 4) Shift (horizontal movement)
 * 5) Gravity
 * 6) Lock
 * 7) Output update
 * 8) Loop to one

In fact this is very complicated, but just be aware of this general concept, and particularly if you want to learn advanced technique in TGM.

Delayed Auto Shift (DAS) [[Image:25%.png]]
Auto shift is vital for gameplay of all Tetris games and allows a player to shift a tetramino automatically by holding left or right. Also called "zoom," the DAS (counted in frame) define the moment between holding a direction (left/right) and the moment the tetramino moves automatically. The DAS can be loaded during ARE. In TGM1 the DAS was fixed to 15 frames, but in sequels the DAS become shorter as the game's speed increased.

Gravity Unit (G) [[Image:25%.png]]
G is the gravity speed indice of TGM, it shows [dropped steps / frame]. For example, the slowest speed count is sixty-four frames for one dropped step and the fastest speed is twenty dropped steps for one frame. TGM field's height is 20, so max is 20G.

<span id="fast_Drop">Fast Drop [[Image:25%.png]]
By holding the down direction, you can force the gravity to 1G, which means the active tetramino will step down faster. If gravity is higher than 1G, the fast drop is deactivated. In ARS, the Lock Delay cancel and Fast Drop use the same input, so if the tetramino lands on the stack during Fast Drop it will lock instantly, unlike SRS.

<span id="Sonic_Drop">Sonic Drop [[Image:25%.png]]
Sonic drop is a feature specific to ARS and unavailable in TGM1. By pressing up, you can force the gravity to 20G during 1 frame. Visually you force the tetramino to land on the stack without locking (unlike sonic lock). Sonic drop allows you to place your tetramino in tight place very quickly and avoid the stacking error consequences of fast dropping. For beginners, sonic dropping with up direction may look strange, but interestingly allows the player to preform convenient Zangi-Moves.

<span id="Sonic_Lock">Sonic Lock [[Image:25%.png]]
Sonic Lock is a feature specific to SRS. By pressing up, you force the tetramino to land onto the stack and lock immediately. At low gravity, Sonic Lock allows you to stack faster than Sonic Drop but doesn't make room for Zangi-Moves since the tetramino locks.

<span id="Lock_Delay">Lock Delay [[Image:25%.png]]
When the tetramino falls onto the stack, it doesn't lock immediately (e.g. tetris gameboy) because a short delay still allow you to move it. Lock Delay is visible to the darkening of the tetramino. This feature is necessary as speed increases and critical when reaching 20G. The delay is expressed in frames and the tetramino automatically locks when reaching zero. Lock delay resets each time the tetramino drops one or more steps. SRS also resets Lock Delay when the tetramino is moving and rotating. TGM1 Lock Delay is fixed to thirty frames (~0.5sec) and diminutive as gameplay speed increase on sequels. You can also cancel the Lock delay by pressing Down.

Initial Rotation System (IRS) [[Image:25%.png]]
By holding a rotation button during ARE you can change the initial orientation appearance for the next tetramino. IRS mellow the gameplay as the gravity increase and reach 20G. You can only reorient the tetramino to 1 quarter turn, witch mean that it is not cumulative (eg A+C buttons), but IRS can be coupled with IHS.

Initial Hold System (IHS) [[Image:25%.png]]
By pushing the Hold button, you can switch the active tetramino with a held tetramino. The new held tetramino orientation resets, and the new active tetramino is replaced on the playfield's top. By holding the hold button during ARE, the switch occurs before the next tetramino appears. IHS mellows the gameplay as the gravity increases and reaches 20G. Holding becomes unavailable (grey color) until the next distributed tetramino, since otherwise you could switch indefinitely. IHS can be coupled with IRS and is a feature only available from TGM3 and TGM ACE.

Temporary Landing System (TLS) [[Image:25%.png]]
The TLS is a simple visual help that show at low gravity where the active tetramino will land if you use Fast Drop, Sonic Drop or Sonic Lock.

Level [[Image:25%.png]]
The level shows the game's progress. Starting from zero, the level increases by one each time a tetramino is distributed, and by the number of completed rows. If you are a beginner at TGM, the level is the best information to see your performances progress, rather than the chronometer.

<span id="Level_Step">Level Step [[Image:25%.png]]
The Level increment can stop when reaching a Level Step (typically _99 : e.g. 99, 199, 299 etc...). You can pass only by completing a row. Each time you pass a Level Step, the game displays a new background. TGM3 also plays a bell ringing sound each time you are close to the Level Step.

Grade Recognition System (GRS) [[Image:25%.png]]
ARIKA rewards a player's skill and performance by grade attribution and divides them into class. For example, here is the sorted grade list for the TGM1 unique game mode :

9, 8, 7, 6, 5, 4, 3, 2, 1, S1, S2, S3, S4, S5, S6, S7, S8, S9, Gm.

Becoming a Gm Class player in TGM1 will require much motivation and perseverance even if comfortable with Tetris games in general. The difficulty to obtain the Gm grade in TGM2 and TGM3 increases in a exponential way. For example, we know that there is an average of 10000 Gm class players in Japan on TGM1. It would be really optimistic to say 100 Gm players in TGM2 Master Mode exist, and so far nobody obtained it in TGM3!

<span id="Wall_Kick">Wall-Kick [[Image:25%.png]]
The wall kick is simply a way to mellow the rotation system. When you want to turn a tetramino and there is no free space for the new requested orientation, the game will try to decal it to the nearest position possible. Depending on the version of TGM and the rotation system (ARS/SRS), the Wall Kick rules are different and less or more flexible.

(several animated gif example to come...)

Synchro [[Image:25%.png]]
A Synchro move is the action to sucessfully input rotation and shift on the same frame. Although less useful in low gravity, but they become essential at 20G for enabling tricky tetramino movements and placements.

Arika Rotation System (ARS) [[Image:25%.png]]
ARS is the native rotation system of TGM, and also called "Classic rules" in TGM3. The basics difference between ARS and SRS came with the tetramino shape color, initial spawn orientation and wall kick rules. In term of gameplay there is more fondamental difference (eg Lock Delay reset), but with the release of TGM ACE, and the frankenstein mix result of ARS1 and ARS2 we should hold us with that.

Super Rotation System (SRS) [[Image:25%.png]]
SRS is the rotation system edicted by the TTC's Tetris Guideline, and also called "World rules" in TGM3. although containing The word "super" (Henk Rogers's credit), SRS have no superior enhancement compared to ARS. The wall kick rules are more flexible, and infinite Lock delay reset design is strongly oriented for beginners.

Description
Zangi-Moves are an original ARIKA technique introduced in TAP made possible by the Sonic Drop feature. To perform the move, you press Up to drop the piece, Left or Right to move the piece over, and Down to lock the piece in place. These 3 inputs are performed with a single circular motion of the arcade stick. This is particularly useful when you are playing for time attack, as you save a significant amount of time by not having to return the stick to its neutral position. Zangi-moves are not possible with SRS.

Useage
This move is most useful for tucking pieces underneath overhangs, an operation that costs much time in most other Tetris games. However, it is also used in other situations where the speed gain is more subtle. If you wish to place a piece 1 space away from the spawning location, you will do so with a half circle Zangi-Move. If you want to place a piece 1 space away from a wall, you will use DAS to get to the wall quickly, and then you will use a Zangi-Move to place the piece, all in one continuous 3/4 circle Zangi-Move.

Word Origin
The word 'Zangi' comes from Zangief's (Street Fighter II) Spinning Pile Driver move, which requires stick rotation and feels similar. The following animations just show Zangi-Moves example and don't follow an optimized stacking behavior.

ARE [[Image:75%.png]]
ARE is the period of time (counted in frame) between the lockdown of the previous Tetramino and the appearance of the next one. Depending on the level, the amount of ARE may shorten.

During ARE
During ARE, the player must wait for the next Tetramino to appear, and cannot actively cause anything to happen. However, ARE serves as a time for the player to input DAS, IRS and IHS actions which will be processed in the moment ARE finishes and the next Tetramino appears.

Word Origin
ARE is a word of Japanese origin, and though it looks like an acronym, it does not stand for anything. It derives from the Japanese word, "あれ (are)," pronounced "a ray" quickly. The word "あれ" is a demonstrative pronoun, literally translating to "it" or "that". Japanese players originally referred to this in-between time using the word "あれ" as there was no good word to describe it. The capital letter alphabet form "ARE" (pronounced ay arr ee) became popular when someone wrote it in that form, possibly owing to its cooler, acronym-like look.

The Existence and Lack of ARE
ARE is a vital gameplay factor in TGM, as its existence allows for many systems like 20G, DAS, IRS and IHS to exist. It does not exist, like most other features unique to TGM, in most games Tetris-Worlds reminiscent games. It is debated whether the lack of ARE is a requirement in the World guidelines or not; TGM3 (Ti) and TGMA in particular, do have ARE even though they seem to follow the guideline.