DAS

Delayed Auto Shift or autorepeat refers to the behavior of most falling block puzzle games when the player holds the left or right key. The game will shift the falling piece sideways, wait, and then shift it repeatedly if the player continues to hold the key.

Some games read the keys as on-off switches and implement DAS in software. Other games, especially earlier games running on home computers, rely on the automatic repeat provided by the hardware or operating system, which the user often has the ability to configure. (In Windows 2000 and Windows XP, this setting is Control Panel > Keyboard > Speed > Character repeat. Likewise, in Mac OS X, the Keyboard & Mouse preferences control the speed of key repeat.)

Some games that have ARE or line clear delays allow the player to "charge" DAS by holding the movement key during these delays, so that the piece starts moving sideways as soon as it appears. Games where ARE or line clear delay becomes faster over time, such as later TGM series games, often decrease DAS delay at the same time.

Games with slow DAS
Tetromino based: Other:
 * Tetris (NES, Nintendo)
 * Tetris (Game Boy)
 * The New Tetris
 * Tetris DS
 * Tetris Online (Japan)
 * Dr. Mario
 * Yoshi's Cookie
 * Zoop

Games with fast DAS
Tetromino based games with at least 20 Hz DAS: Other:
 * Tetris (Sega)
 * Tetris Blast
 * Tetris DX
 * Tetanus On Drugs and its GBA port Lockjaw: The Overdose
 * Tetris The Grand Master series
 * Lockjaw (for PC)
 * Tetris Attack

Practical considerations
Tactics for placing tetrominoes differ per game based on the speed of DAS and based on whether the player can load DAS during a line clear.

One space from the wall
To place a T, L, or J tetromino with its flat side one square from the side of the matrix at low gravity, it is fastest to rotate the tetromino after moving it. In bounding box based rotation systems such as SRS or its immediate predecessors, this applies to S and Z as well.

Rotate before move, tap tap tap:

Rotate before move, DAS then backtrack:

Rotate before move, DAS then let go before the tetromino hits the wall, leads to misdrops, especially in games with fast DAS:

Move before rotate:

However, at fast gravity, rotation (especially initial rotation) before movement may help the player navigate pyramid structures.

In SRS for games with fast DAS, moving to the right wall then rotating uses less button presses in cases with all pieces except O. With J, L, and T, moving to the right wall, rotating and then moving once more left is faster still (two movements) than tapping three times right. With I, moving to the right wall and rotating clockwise is faster, as well as rotating counter-clockwise for the third column-- and vice versa for the left wall. In other rotation systems such as TGM Rotation, this technique works halfway, which some pieces can benefit from rotating after moving to the wall on the left-- others on the right.