The Oxybeles moves like a king, one step in any direction, but it cannot capture in this way. Instead the Oxybeles, when it moves, has the power to sling a piece located behind itself to a forward square in the alignment direction. The slung piece, which can be of any colour, is located immediately behind the Oxybeles, in the opposite direction of the move. This piece can hit an enemy piece in the forward direction, provided that any intermediate squares are empty. If there is no enemy piece then the catapulted piece lands on the remotest square in a series of empty spaces. Thus the Oxybeles can be used for transporting friendly pieces, attacking enemy pieces, or removing enemy pieces from good positions. Pawns can be catapulted to their promotion square, when they are promoted to queen as only alternative. Pawns cannot be catapulted to the first rank, that is, the second rank is the limit. Kings and rooks retain their castle rights if catapulted away and back, while they haven't moved by their own accord. Other rules are the same as in standard chess, except for the possible promotion to Oxybeles.

You can play Oxybeles Chess online, or per email, here.