Citadel Chess
Citadel Chess — starting position
https://engine.moddable.games/play/?game=chess&variant=citadel-chess
Citadel Chess (Shatranj al-Husun, “Chess of the Fortresses”) is a historical Shatranj variant described by Gollon (based on Murray and Pritchard). It is played on a 10×10 board augmented with four corner citadel squares. A King that reaches the opponent’s citadel and cannot be captured on the very next move secures a draw.
The Board
The main playing area is a 10×10 grid (files b–k, ranks 2–11). Four additional citadel squares are positioned diagonally off each corner of the main grid:
- a1 and l1 — White’s citadels (adjacent to White’s back rank)
- a12 and l12 — Black’s citadels (adjacent to Black’s back rank)
Ranks 1 and 12 contain only the citadel squares (a1, l1, a12, l12); squares b1–k1 and b12–k12 do not exist. Files a and l have no squares other than the citadels. Total board size: 104 squares.
Starting Position
White back rank (rank 2): Rook b2 · Knight c2 · War Machine d2 · Elephant e2 · King f2 · General g2 · War Machine h2 · Elephant i2 · Knight j2 · Rook k2
White pawns (rank 3): b3–k3 (10 pawns)
Black back rank (rank 11): Rook b11 · Knight c11 · War Machine d11 · Elephant e11 · King f11 · General g11 · War Machine h11 · Elephant i11 · Knight j11 · Rook k11
Black pawns (rank 10): b10–k10 (10 pawns)
Source note: The chessvariants.com source lists “Elephant c2, i2” but c2 is also given as the Knight square. By symmetry (Rook–Knight–War Machine–Elephant–King–General–War Machine–Elephant–Knight–Rook), the Elephants occupy e2 and i2.
Pieces
| Piece | Movement |
|---|---|
| King (Shah) | One square in any direction |
| General (Firzan) | One square diagonally |
| Elephant (Fil) | Leaps exactly 2 squares diagonally; can jump the intervening square |
| Knight (Faras) | L-shaped leap (as in standard chess) |
| Rook (Rukh) | Slides any distance orthogonally |
| Pawn | One square forward; captures one square diagonally; no double first step; promotes to General on reaching the last rank |
| War Machine (Dabbabah) | Slides any distance diagonally (as a modern Bishop) |
Citadel Rules
- A King may move into a citadel square on the opponent’s side of the board (a12 or l12 for White; a1 or l1 for Black).
- If the King enters the opponent’s citadel and cannot be captured on the very next move, the game is a draw.
- A player’s own citadels (on their own side) grant no special benefit.
Special Rules
- Stalemate is a win for the stalemating player.
- No bare King rule — the game continues normally when a player has only the King.
- No castling, no en passant.
- Promotion: Pawns promote to Generals upon reaching the last rank.
Attribution
Citadel Chess documented at chessvariants.com/historic.dir/citadel.html (Hans Bodlaender, from Gollon/Murray/Pritchard).