Tetris: The Grand Master

Tetris: The Grand Master (often abbreviated TGM) is a series of puzzle games created by Arika, Inc. based on the popular Tetris license. The Grand Master series of games introduced several play mechanics to Tetris gameplay which can be seen today in its sequels, and many other Tetris implementations.

TGM was followed by two sequels, also developed by Arika: Tetris: The Grand Master 2 - The Absolute in 2000, and Tetris: The Grand Master 3 - Terror-Instinct in 2005. A console version, Tetris: The Grandmaster ACE was published by AQ Interactive on December 10, 2005 and was a launch title for the Xbox 360's Japan release.

Gameplay
The basic gameplay of TGM is similar to those of other Tetris games. The player must move and rotate tetromino-shaped pieces falling into a well to form horizontal lines, which will then be cleared. During gameplay, the game automatically gives ranks (or 'grades') to the player according to his/her score, starting from 9 all the way up to GM (Grand Master).

Levels in TGM
In most Tetris games, the game level (signifying its difficulty) will increase by one every time the player clears 10 lines. A different system is used in TGM, however. Levels in TGM increase by one for every piece placed and locked down, and for every line cleared. The exception to the rule is when the lower two digits of the level is at 99. (99, 199, 299...), and on 998. When in this state, the level can only increased by clearing lines, and not by placing pieces.

The ultimate goal of the game is to reach level 999, the highest level, and attain the GM rank.

20G (Instant Gravity)
The fall speed is measured in units called G, or grid cells per frame. For the first 300 levels, the game speed is less than 1G. After reaching level 500, the falling pieces cease to have an airborne phase, and instead will instantly appear at the bottom. This state is referred to by developers of the game as 20G. This change in behavior modifies the gameplay mechanics significantly, to a much more strategic game. When previously players would align the horizontal position while the piece is still airborne, and then drop the pieces, this becomes impossible since the pieces are already at their lowest possible vertical positions when they appear. Instead, players are required to quickly trundle the pieces along the terrain to get them to their intended locations, before they lock down. Similar conditions can be observed in some modern iterations of Tetris, such as level 20 of Tetris DS.

Lockdown
Carrying over a trait from its spiritual ancestor, Sega's Tetris, the pieces do not lock immediately when it comes in contact with the placed blocks on the screen (unless Down is held when the tetromino is in mid-air). Similar, but not identical, behavior can be seen in the later Tetris Worlds series. The pieces can be maneuvered for a half second on the same line it was dropped before it locks (meaning the player can drop the tetromino one line to restart the lock-down timer). This can be a great strategy for undesirable drops, and fitting in tetrominoes strategically in gaps.

Grades (GRS)
Grades are used to keep a cumulative record of a player's success when playing. During gameplay, the player's current grade and the points required to get the next grade are always shown at the top left of the playfield. The grade starts at 9, and eventually decreases to 1 which then changes to S1. Afterwards the number will increase, up to S9, and to the GM, the highest rank of the game. A player can reach a high score list by reaching a specific grade level in a fast time. The system used on TGM favors speed rather than attempting to survive as long as possible as with most other Tetris games.

Rotation rules
The basic rotation rule of TGM is identical to Sega's Japanese arcade version of Tetris, as most of the rule details of TGM are derived from Sega Tetris. It is unique in that no single center of rotation exists; instead, the J, L, S, T, and Z tetrominoes rotate so that the lowest grid block is always of the same height.

One difference from Sega's Tetris is the existence of rotation compensation, also called "wall kick". This applies a slight nudge to a tetromino in some cases where rotating it would bump into a wall. First it will try to move the piece one cell right, and then if that fails, one cell left. If both fail, rotation will not work.

Tetris The Grand Master
The original game, released in Japanese arcades in August 1998.

Tetris The Absolute The Grand Master 2
This upgrade to the original TGM added additional modes of play. One of these new modes is the "Master" mode - which extends the classic TGM gameplay with larger speed increases, more requirements to achieve the M or GM grades, and the additional challenge of the "M-Roll" when the M rank is achieved, a special credits roll is played in addition to a final challenge where the player must survive the credits roll without topping out, with the additional handicap of the tetrominoes turning invisible upon locking. Additional modes included a more casual "Normal" mode, Versus mode being enhanced with item battles, and a two-player co-op mode.

A free patch, known as "Plus", added additional modes, such as "TGM+" which adds rising garbage blocks to the gameplay, and the infamous "T.A. Death" mode - where the game begins at 20G mode, and every other aspect of the game also speed up steadily as well. A video of a Japanese player breaking Level 800 in this mode has been a viral hit on video sites such as YouTube.

Tetris The Grand Master 3: Terror Instinct
Tetris The Grand Master 3 Terror-Instinct, commonly known as TGM3 or just Ti was released in 2005. The game now runs on PC-based hardware, specifically the Taito Type X. The level system has been expanded in many forms, with increasingly stricter requirements to reach the Grandmaster rank. Modes include "Easy", "Sakura" (a puzzle mode), the traditional "Master" mode, and "Shirase" - an extension of T.A. Death, with even harsher speed, garbage, and levels beyond 999.

Tetris The Grand Master 4: The Masters of Round
In September 2009, Tetris The Grand Master 4: The Masters of Round was unveiled at Sega's Amusement Machine Show. At least three modes of TGM4 have been shown so far: "Master" mode, "Konoha" mode (a mode in which all pieces are double size and the object is to completely clear the playing field of blocks as many times as possible), and "Rounds" mode (similar to T.A. Death and Shirase modes, but with more levels and a fog mechanic that prevents line clears below a particular height until certain conditions are met). TGM4 will run on the Sega Ringwide hardware.