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 Sega colors, 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.

ARS basics rotations.

Wall kick

Illustration goes here.

Sometimes a rotation is blocked by the walls outside the playfield or by blocks inside the playfield. Most often, TGM tries to rotate the tetromino within the box without moving it, then try wall kicks: one space to the right, then try one space to the left, then fail. In some special cases, TGM skips these displacements. TGM2 and Sakura Tetris use the same system as TGM.

If the marked block is occupied when rotating from this position, TGM will not attempt wall kicks.

TGM3 also tries a floor kick when rotating a T or I tetromino to some orientations.

References

• colour_thief's explanation of ARS wall kick on the tetrisconcept.com forum
• TGM rotations, in Japanese