In Reserve Chess (R-chess) one extra piece per player is placed in the reserve. The piece is automatically introduced at the position that is first left vacant when a piece leaves its initial square. The piece that first moves will also bring the external piece into play, so it is a double-move, comparable to castling. Otherwise the rules are the same as in standard chess.

This implementation will allow the user to test which pieces are suitable. It will be enhanced with more alternative pieces in later editions. Reserve Chess is designed to overcome the problem of opening monotony.

reserve n, often attrib (1648) 1 : something reserved or set aside for a particular purpose, use, or reason: as a (1) : a military force withheld from action for later decisive use. Usu. used in pl.

So far, these pieces have been implemented: Swedish Cannon, Chancellor, Archbishop, Amazon, Mastodon, Dimachaer, Trebuchet, Kwagga, Divaricator, Murmillo, Culverin, Belfry, Adjutant and Zeppelin, Consul, Dragonet, Camel (3+1), Llama, Alpaca, Guanaco, and Vicuña.