An Overview of Kicks in SRS
Wall kicks were initially introduced in Tetris to solve the problem of not being able to rotate minos when they were up against a wall.
Since then, several rotation systems have been introduced to address this, and Super Rotation System, or SRS, is the current standard of how minos behave. Here's a brief overview of how wall kicks work in SRS.
This is a T mino, and the four rotation states that it can be in: North, West, South, and East, respectively.
This is a kick used by a T-Spin Triple:
In Super Rotation System, or SRS, if a mino cannot regularly rotate because of an obstructing block, the game will sequentially attempt to place the mino into four different positions with slightly different offsets.
For a T rotating from North to West like the above example, the four alternate positions that the game will test are as follows:
If one of these alternate positions work, the mino will be placed in that position.
For this example, we can see how the normal rotation and the first three tests fail, but that the fourth test succeeds. In the end, it appears as if the mino was "kicked" into that place.
If none of them work, nothing will happen.
Here's another much simpler example. The regular rotation doesn't work, but the first kick test succeeds. This is a T-Spin Mini.