• Board
• Objective
• Play
• Variants

Metamorphosis is played on a square board using special two-colored pieces: one side of a piece is colored black and the other side is colored white.  The left and right edges of the board are colored white while the top and bottom edges are colored black.  The initial position of the pieces is shown in the following picture:

The goal of Metamorphosis is to form a chain of pieces of your color connected either horizontally or vertically linking the opposite edges of the board marked by your color after your opponent has moved.  It means that the player's chain must still connect both of his sides after the opponent's replying move. A corner is considered to be part of both adjoining edges. 

Draws are possible in Metamorphosis, though they seem rare.

Starting with Black, players take turns flipping a piece (i.e. turning a black piece into white one or a white piece into a black one).

Each turn a player must decrease the total number of "groups" (a "group" is a set of pieces of the same color connected either horizontally or vertically; at the beginning of the game there are N²  "groups").

Since the first player has a distinct advantage, the pie rule is used to make the game fair.  This rule allows the second player to switch colors after the first player makes his first move.