Infinity is the Tetris Company's term to refer to a characteristic in recent Tetris Guideline-compliant games where the lock delay of a tetromino is reset whenever it is moved or rotated (even O, which ordinarily does not rotate).
The feature can also be referred to as move reset, although the term in particular does not hold the connotation of rotations also triggering a countdown reset. Rotation will reset the lock delay for all pieces, including O which does not change shape when rotated.
This controversial feature allows a single tetromino to be easily kept "alive" forever. To reduce the negative effects of this, newer Tetris games tend to have modes that reward play speed, such as points per minute or garbage per minute. also, while the number of times the player can move or rotate a piece is usually unlimited, limits can be instated in certain situations like versus play or arcade situations where infinite prolonging of play is undesirable. In situations where such limits are in effect, the tetromino automatically locks down after the player resets the lock delay for a set number of times. In a few console games, the feature can be turned off, where in one instance the game reverts to a step reset lock delay behavior.