Historical notesThe moa is a variant of the mao, a piece that originates from Xiangqi, Chinese Chess. The mao is also used in some fairy chess problems. The variant Moa originated in the world of fairy chess problemists. Both pieces make an obstructed knight-move, but where the mao first moves orthogonally and then diagonally, the moa first moves diagonally and then orthogonally.
MovementThe moa is similar to the chess knight - it ends up the same distance away, but it can not jump over intervening pieces like the chess knight. Rather, the mao is considered to move first one square diagonally, and then one square orthogonally (away from the starting square) to its destination square. The intermediate square must be empty.
Note that this makes it possible for the moa to pin pieces, and that it is possible for a moa to attack an opposing moa without that moa attacking back.
Movement diagramIn the diagram below, the White moa on d5 can move to all the squares marked with a black circle. It can capture the Black moa, even though the Black moa can not capture the White one. Also note that the Black king is not in check, but that the Black rook is pinned.
This is an item in the Piececlopedia: an overview of different (fairy) chess pieces.
Written by Hans Bodlaender, based on description of Mao of Ben Good. Thanks to Alfred Pfeiffer for spotting errors in the diagram.
WWW page created: December 23, 1999. Last modified: December 30, 1999.