Arika Rotation System

TGM rotation is a game play mechanic used in Tetris The Grand Master and other Arika tetromino games, derived from Sega rotation.

Games using TGM rotation generally use IRS, fast DAS, lock delay, and firm drop, and tetrominoes start out with the topmost block on the top row (generally row 20). Tetris The Grand Master Ace uses a hybrid of TGM rules and Guideline rules.

Basic rotation

TGM's basic rotations inherits most of its properties from Sega rotation, which was used in most previous Japanese arcade Tetris games. Some defining design choices include:

• Having 2 (as opposed to 4) rotation states for S, Z, and I pieces to simplify learning.
• Keeping pieces at an even level while rotating to always allow rotation when the piece is on a flat surface.
• Pointing the initial stance of the T, L, and J pieces downward to add some extra challenge and also make it easy to have pieces grab bumps along the surface of the stack when playing at high gravity.

TGM's basic rotations.

Wall kicks

TGM pioneered the use of wall kicks, with simple but effective kick rules. These rules were unchanged until TGM3, remaining constant across TGM, TA, TAP, and Sakura Tetris. Up to 3 locations are tried, in this order, before rotation will fail:

• Basic rotaion
• 1 space right of basic rotation
• 1 space left of basic rotation

In addition to these rules, there are some extra exceptions where certain wall kicks are not allowed:

• The I piece will never kick.
• L, J, and T pieces will not rotate in the situations illustrated below if the marked block is occupied.

• However, L pieces will rotate clockwise and J pieces counterclockwise in the situations illustrated below if both the marked blocks are occupied.

New wall kicks in TGM3

I tetromino's wall kick

In TGM3, I tetromino can kick walls. There are 3 different types of wall kick.

Try to rotate	Basic rotation fail	Kick 1 space right
Try to rotate	Basic rotation fail	Kick 2 space right
Try to rotate	Basic rotation fail	Kick left

I tetromino's floor kick

I tetromino can kick floor.

Notes:

• This action can perform only once.
• This action causes lock delay reset.
• The tetromino cannot kick the floor in mid-air.

Fail

OK

OK

There are 2 different types of floor kick.

Try to rotate	Basic rotation fail	Kick 1 space up
Try to rotate	Basic rotation fail	Kick 2 space up

T tetromino's floor kick

T tetromino can escape from a hollow.

Notes:

• This action can perform only once.
• This action causes lock delay reset.

Try to rotate

Basic rotation fail

Kick up

To-Do

• describe ACE's ARS and ARS2
• describe "Mihara's conspiracy"
• mention right bias
• add more visual aids?

References

• KAN's detailed explanation of TGM3's new I and T floorkicks
• TGM rotations, in Japanese