General controls
Not all Tetris game contain the same controls, or even the same options for controls. What follows is a general description of controls commonly found throughout the variety of Tetris games available.
Shifting left or right
As each appears and begins to fall, you must decide where to place it on the stack. This will generally involve moving each piece left or right until the piece is positioned where you would like it to fall. This is generally accomplished by pressing left or right on a joystick, a direction pad, or the left and right arrow keys on your keyboard.
Delayed Auto-Shift
DAS is a feature whereby holding a joystick or key in one direction initially only shifts a piece one column in the desired direction, and then after a pause, begins to slide the piece over continuously. Some games have a fast DAS (meaning there is very little pause between the first movement and the slide) while other games have a slow DAS (there is a big pause between the first movement and the slide).
Rotating clockwise or counterclockwise
Maneuvering a piece into the best position to clear lines from your stack involves more than just sliding pieces left and right. You must also rotate them and orient them so that they settle on to your stack without leaving gaps or holes.
If the version you are playing only offers one button, then you are restricted to one direction of rotation. This is typically performed by pressing the one button that's available, or in some cases, it can be performed by pressing up on your joystick or direction pad.
If the version you are player offers two or more buttons, then you have the ability to choose between a clockwise rotation and a counter-clockwise rotation. At lower levels when the pieces fall relatively slowly, the distinction isn't as important since you can spin your piece multiple times and still have time to place it where you want it. However, when the levels increase and your pieces are falling dramatically faster, knowing how to rotate your piece to the desired orientation in the fewest taps possible is much more important.
Rotation systems
While rotating a piece clockwise or counter-clockwise can sound very straightforward, different versions of Tetris employ a few different rotation systems which can affect the way the current piece turns when it is close to or against another piece, or the wall of the Matrix. See the Template:~ page for more information about this subject. Additionally, versions differ when it comes to determining what happens to a piece when you try to rotate it against the wall of the Matrix. Some games employ a system known as a "Wall kick" which can push your current piece away from the wall in order to accomplish the rotation.
Drops
Gravity is always in effect throughout the game, so your piece will eventually fall to the bottom of the Matrix and settle above the floor or near the top of your stack. However, there are times, particularly early on in the game when the speed of the game is slower, when you wish to direct a piece to fall faster so that you can resume play with the next piece. In order to accomplish this, many versions of Tetris provide you with a means to drop your current pieces. There are two different kinds of drops, and not all versions of Tetris offer both varieties.
Soft Drop
A soft drop simply speeds up the rate at which the current piece is dropping, so that it falls faster, but not instantaneously, to the bottom of the Matrix. And typically, the player has the ability to stop and resume soft drops at will, as long as the piece hasn't landed on anything yet. In most cases, this is accomplished simply by holding down on the joystick or direction pad.
Hard Drop
A hard drop will instantly drop a piece to whatever it is situated above, lock it in place so that it can no longer be moved or rotated, and instantly advance you to the next piece. When employing a Hard Drop, you must be absolutely sure that where the piece lands is where you want it to go, as there is no ability to undo a Hard Drop. This is best used in versions of the game that display a Ghost piece so that you can be certain of where the piece will go. It is typically performed by pressing Up on a joystick or direction pad on newer versions of the game, or by pressing a designated button or the space bar.