Tetris is primarily composed of a field of play in which pieces of different geometric forms, called “tetriminos”, descend from the top of the field.
During this descent, the player can move the pieces laterally and rotate them until they touch the bottom of the field or land on a piece that had been placed before it.
The player can neither slow down the falling pieces nor stop them, but can accelerate them in most versions. The objective of the game is to use the pieces to create as many horizontal lines of blocks as possible. When a line is completed, it disappears, and the blocks placed above fall one rank. Completing lines grants points, and accumulating a certain number of points moves the player up a level, which increases the number of points granted per completed line.
In most versions, the speed of the falling pieces increases with each level, leaving the player with less time to think about the placement. The player can clear multiple lines at once, which can earn bonus points in some versions.