Garbage

Garbage is a form of "attack" in multiplayer Tetris that has been around since Tetris (Game Boy). Sending garbage is done by clearing multiple lines, which causes rows with holes to appear at the bottom of your opponent's playfield. Games with color graphics typically show garbage rows in gray as opposed to the rest of the playfield having colored blocks

Garbage System

Clearing more lines at once will cause more garbage rows to be sent to your opponent.

General Garbage System in Guideline Games

Clear Type	Rows Cleared	Garbage Rows Sent
Single	1	0
Double	2	1
Triple	3	2
Tetris	4	4
T-Spin Single	1	2
T-Spin Double	2	4
T-Spin Triple	3	6
Back-to-Back Bonus	0	+1

Some games will deviate from this. For example, sending more than one gap per row (Tetris The Grand Master Ace) or having 1:1 clear to send ratio (Super Tetris 3).

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 1:1000.

Some games, like Tetris DS feature semi-random garbage output. With random garbage, the player will receive at least a double's worth of aligned holes 10% of the time. Empirical data suggests Tetris DS leans closer to 72%.

Early games like Tetris (Game Boy) will switch the garbage's hole column every nine rows or so.

Some players prefer pure random garbage because aligned garbage tends to "see-saw" back and forth wildly. Others enjoy the depth and challenge presented by random garbage.

Tetris Worlds is currently the only game which lacks retaliation garbage, meaning clears from garbage will not send back any garbage. Because of this, clearing garbage becomes less desirable, which a player may argue deprives the game of some depth.

Gameplay Example

The left diagram shows the player's field while the right shows his opponent.

If a player drops a "T" here:

It will clear two lines at once, sending one row of garbage to the opponent:

Then, if the player drops a tetris here:

It will clear four lines at once, sending four lines of garbage to his opponent.