Tetris DX

Tetris DX
Developer(s)	Nintendo
Publisher(s)	Nintendo
Platform(s)	Game Boy Color
Release	21, Oct 1998 (Japan) 31, Oct 1998 (USA) 1, Jul 1999 (Europe)
Gameplay info
Next pieces	1
Playfield size	10x18
Hold piece	No
Hard drop	No
Rotation system	Bounding box, wall kick, SRS predecessor

Not to be confused with Tetris Deluxe, a game released for western mobile phones.

Tetris DX was a Game Boy Color game as an enhancement of Nintendo's original Game Boy Tetris, with two added gameplay modes (Ultra, lasting 3 minutes; and Vs. CPU, a match against the computer), a profile/save feature, and color graphics on Game Boy Color and above. In addition, the game's rotation system had a glitch which lets a player move any tetromino except O upward by holding the direction against a wall while rotating in the opposite direction.

Modes

• Marathon (score maxes at 9,999,999)
• True 40 lines mode (not 40 "points" like in Tetris Worlds)
• Vs. CPU opponent

Rotation system

All rotation states of all seven tetrominoes in TDX. From top to bottom: I, J, L, O, S, T, Z. The circle doesn't appear in the game; it helps to illustrate the axis on which each tetromino rotates.

The rotation system is an early version of what would become SRS. Like in SRS, tetrominoes of width 3 rotate as if in a bounding square; unlike in SRS, L, J, and T start flat side up. TDX first tries rotation about the center of the box (the blue circle). If this fails, it tries rotation about an alternate center displaced by one cell (the gray circle). For I, S, and Z, this center starts out one cell above the ordinary center; for L, J, or T, it starts out one cell below.

Wall climbing

This rotation system is exploitable, especially on low levels:

Charge DAS

Rotate left

Shift left (DAS)

Rotate right about alternate center

This particular exploit was fixed in SRS.

Infinity

Ordinarily, Tetris DX lock delay follows step reset behavior: only downward motion under gravity resets the lock delay timer. But rotation about the alternate center does reset the timer used for gravity. This can be exploited by placing a piece in a corner and rotating it back and forth about the alternate center:

External links

• Koryan's description of Sega Tetris, TGM, and Tetris DX rotation systems (Japanese language)
  • English translation using Google Language Tools