Modern chess starting setup. Each prime minister is to the left of its king.
Modern chess is a chess variant played on a 9×9 board. The game was invented by Gabriel Vicente Maura in 1968.[1][2] Besides the usual set of chess pieces, each player has a prime minister and an additional pawn:
The first match was played in Madrid at Escuela de Bellas Artes de San Fernando's cafe on March 18, 1968. The players were Gabriel Vicente Maura himself (White), and Bonifacio Pedraz Cabezas (Black).
Game rules
The starting setup is as shown. All the standard rules of chess apply, along with the following special rules:
A player can castle either ministerside (notated "0-M-0") or queenside (notated "0-Q-0");[1] in either case the king slides two squares toward the castling rook.
When reaching the final rank, pawns can promote to one of the usual pieces or to prime minister.
Optional rule
In response to criticism that bishops are restricted to only one square color, the inventor proposed an optional new rule, if the players agree:
One bishop may switch its position with a piece adjacent to it, provided that the bishop and the piece adjacent have not yet moved in the game. The switch is counted as a normal move. The notation for the move is B=[adjacent piece used]; for example B=Q for bishop and queen switch, or B=MN for a switch of the bishop and the minister's knight.
According to Ed Friedlander, in the countries where the game is played more commonly, another popular way to create a light square bishop is to require that one of the bishops must move one square orthogonally as its first move.
Pritchard, D. B. (2007). "Modern Chess [Maura]". In Beasley, John (ed.). The Classified Encyclopedia of Chess Variants. John Beasley. ISBN978-0-9555168-0-1.
