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Prime Ministers Chess

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Prime Ministers Chess is an adaptation of Gabriel Vicente Maura's 1968 Modern Chess (9 columns, simple reverse symmetry, symmetric castling to either side, an extra pawn, the Prime Minister (B+N) and the Bishop Adjustment Rule) to a 9x8 board.

Prime Ministers Chess Preset

While the setup described above (with Prime Minister to the left and Queen to the right of the King, and with reverse symmetry) is the original and prefered setup, the symmetry of the board allows three additional and alternate setups. The setups below are all valid Prime Ministers Chess starting layouts, for which the game can still be played under the same rules:

Note that the first alternate setup on the left also displays simple reverse symmetry, while the other two alternate setups use direct symmetry accross the board.

The code name for the main Prime Minister Chess layout (the layout same as Maura's Modern Chess) is PMC1 (or just PMC). The code names for the alternate layouts above are PMC2, PMC3 and PMC4 respectively.

Prime Ministers Chess Preset (alternate setup 2 - QKM/mkq)

Prime Ministers Chess Preset (alternate setup 3 - MKQ/mkq)

Prime Ministers Chess Preset (alternate setup 4 - QKM/qkm)


Most Orthodox Chess rules apply, including the objective of the game, the way pieces move and capture, en passant, check, checkmate, and the various draw situations (i.e. stalemate, insufficient mating material, threefold repetition, 50-move rule). Pawns may promote to a Queen, Minister, Rook, Bishop or Knight. The castling rule and the Bishop Adjustment Rule are below.

  • Symmetric Castling to either side. In the 9x8 setup castling is long (O-O-O) on both sides of the board:

    • O-O-Oc is Kc1 & Rd1 [Kc8 & Rd8 for black]
    • O-O-Og is Kg1 & Rf1 [Kg8 & Rf8 for black]
  • The Bishop Adjustment Rule

    • Players on their turn, are allowed to convert one (and only one) of their Bishops to the opposite color square by swapping places with any piece adjacent to them.
    • Neither the Bishop nor the piece to be adjusted with may have moved before the Bishop swap.

    Game Courier Logs

    Game Courier Logs for Games of Prime Ministers Chess

    To see actual games that have been played on-line, follow the link above.


    Prime Ministers Chess (PMC) was proposed by José Manuel Carrillo-Muñiz, from Puerto Rico, in June 2008.

    This 'user submitted' page is a collaboration between the posting user and the Chess Variant Pages. Registered contributors to the Chess Variant Pages have the ability to post their own works, subject to review and editing by the Chess Variant Pages Editorial Staff.

    By Jose Carrillo.
    Web page created: 2008-06-01. Web page last updated: 2008-06-05