Morphos is a drawless connection game for two players: Black and White. It is played on the intersections (points) of an initially empty square grid (board). The top and bottom edges of the board are colored black; the left and right edges are colored white.
Black plays first, then turns alternate. On your turn, place a stone of your color on an empty point of the board or replace (flip) a weak enemy stone with a stone of your color. A weak black stone is a black stone that is part of at least one of the following two patterns or their translations, rotations or reflections:
Black stone on b2 and white stones on b3, a3, a2 and b1.
Black stone on b2 and white stones on a4, a3, a2, b1 and c1.
Likewise, with colors reversed, for weak white stones. The status of any points outside those patterns is irrelevant. For the purpose of identifying weak stones, the colored edges of the board represent additional lines of stones of their respective colors located next to the board, with a length equal to that of a normal row or column of the board.
Passing is not allowed, but, if you have no legal moves available, your turn is skipped.
You win if there is a chain of orthogonally connected stones of your color touching the two opposite board edges of your color.
To make the game fair, White will have the option, on their first turn only, to swap sides with Black instead of making a regular move.
VariantsThe following mutators can be used (together or separately) to alter the character of the game:
a) Both weak-stone patterns have the stone in the top left corner removed from them, and the colored edges of the board do not count as lines of stones (i.e. only real stones count). This results in a game reminiscent of Crossway, but somewhat slower and free of illegal moves on empty points. All other mutators on this list work best when combined with this one.
b) A stone that was flipped by your opponent on their latest turn still counts as a friendly stone for flipping purposes. In this case, the winning condition must be checked for a player at the start of their turn, and it is illegal to flip a stone if the opponent could flip it back on their next turn.
c) On your turn, place two stones of your color on empty points (or one, if there is only one empty point) or flip one weak enemy stone. Black starts the game by placing just one black stone, and the pie rule is not used.
d) When you remove an enemy stone and there are empty points on the board, place the removed stone next to the board. On their next turn, your opponent must place the stone back on an empty point of the board and then make a regular move.
e) Before the start of the game, the board is filled with stones in a checkered pattern. This results in a game very similar to Metamorphosis but without draws.