# Difference between revisions of "Piece"

aceloudr A piece in Tetris and similar games is a geometric shape consisting of a set of blocks that is moved as a unit. A block is the part of a piece that fills one unit of the playfield. In some games, all blocks that make up a piece are colored the same; in others, especially falling piece games other than Tetris and its clones, they are colored differently.

## Polyominoes

A polyomino is a piece made of two or more square blocks, where all blocks are connected through full coincident edges (as if squares on graph paper).

• A free polyomino is one that may be translated (moved about), rotated, or reflected.
• A one-sided polyomino is one that may be translated or rotated.
• A fixed polyomino can only be translated.

Polyominoes come in several sizes:

Polyominoes are often named by a Latin letter that resembles the shape of the polyomino. For instance, an "I" has all its blocks in a straight line, and a "T" consists of an "I" tromino with one or more blocks in a straight line connected to one side of the center of the "I".

## Hinged polyominoes

Hinged tetrominoes
in Tetris 2

A hinged polyomino or polyplet[1] is similar to a polyomino but also allows connections at a point. In games that use hinged polyominoes, a piece may break apart at the diagonal connections when it lands, and the fragments may or may not be controllable afterward.

## Other polyforms

Hextris and Bikaka are variants of Tetris that use 4-cell polyhexes, or pieces created from regular hexagons.[2] Bubble Bath Babes uses polyhexes that may be reflected around the X or Y axis but not rotated.