Garbage

Garbage is a form of "attack" in multiplayer Tetris that has been around since the days of the NES. The basic gist of it is that if you clear multiple rows of tetrominoes at one time, extra rows, with a gap will add to the bottom of your opponent's playing field.

Garbage System

The garbage system is simple. The more rows you clear at once, the more garbage rows are sent to your opponent:

Number of rows cleared	Number of rows sent
1 row	0 rows
2 rows	1 row
3 rows	2 rows
4 rows	4 rows

However, in Tetris DS, the garbage system adds bonuses for Back to Back line clears, as well as adds more garbage for the different T-Spin clears.

Gameplay Example

The left diagram shows Player 1 while the right shows Player 2.

If Player 1 drops the "T" here:

It will clear two lines at once, sending one row of garbage to Player 2:

Then, if Player 1 drops a tetris here:

It will clear four lines at once, sending four lines of garbage to Player 2.

Games with random garbage, like Tetris Worlds, will mathematically output two aligned garbage holes (an easy double) 1:10 garbage lines, three aligned every 1:100, and four aligned every 1:900. A person can find the latter by 1 / (1/1000+10^4+10^5+...10^18) = (1 / 900).