Scirocco is a chess variant on a 10x10 board. Initially each player has 27 pieces of 18 different types. Each of these pieces (even the King) has a distinct promoted form, moving differently from the initial, unpromoted piece. Promotion of a piece is always optional, and can be done at the end of any move with it that starts or end in the promotion zone formed by the farthest three ranks of the board. Once promoted a piece cannot unpromote or promote again.
A game is won by checkmating or stalemating the opponent, or capturing all his non-royal pieces ('baring' the royal). The latter finishes the game immediately, so that it is safe to leave your King in what otherwise would be check after the baring move. Baring is thus similar to King capture, making your last non-royal effectively royal too.
Repeating a position that occurred before also ends the game. The player that made the last move (and thus caused the repetition) then loses, unless none of the moves since the previous occurrence of the final position by either player attacked anything; in that case the game ends in a draw. There is no limit on the number of reversible moves; the only other way to draw is by mutual agreement.
Other rules are as in orthodox chess. White starts to play.
Apart from the promotion rules (which makes Scirocco more like a shogi variant than a chess variant), there are several other peculiarities. Some pieces can capture like in Checkers, by jumping over an adjacent piece to the empty square behind it. Another piece can capture adjacent enemies without moving ('rifle capture'); the entire move consist of just taking such an enemy piece from the board. There are also pieces that induce moves in other friendly pieces instead of being able to capture foes. Any friendly piece in the range of such a move inducer can then gets its move repertoire expanded. Finally, many pieces are divergent, meaning that they capture in a different way from how they move to empty squares. In orthodox Chess only Pawns have this property.
The board is a 10 x 10 checkered squares with a white one at the right end of each player.
There are 27 pieces per side:
Moves and captures as in orthodox Chess, but no initial double-push, and thus no en-passant capture. Promotes to Tadpole
Moves one step orthogonally, captures one step diagonally. Promotes to Zebra.
Moves and captures one step orthogonally. Promotes to Zig.
Moves and captures one step diagonally. Promotes to Zag.
Moves and captures two steps diagonally (possibly jumping over an occupied square). Promotes to Bishop.
Moves and captures two steps orthonally (possibly jumping over an occupied square). Promotes to Genie.
Moves and captures two steps diagonally (possibly jumping), or captures one step orthogonally. Promotes to Queen.
Moves and captures two steps orthogonally (possibly jumping), or moves without capturing one step diagonally. Promotes to Lioness.
Moves and captures like an orthodox King, but is not royal. Promotes to Wildebeest.
Moves and captures like a Knight in usual Chess. Promotes to Rook.
Moves and captures directly to squares three steps removed from it in one orthogonal dimension, and one step in the other (like a Knight, but landing one step further away). Promotes to Squirrel.
Moves and captures like a Knight, or one step orthogonally. Promotes to Abbot.
Moves and captures like a Knight, ore one step diagonally. Promotes to Duke.
Moves and captures like an orthodox Rook, but cannot end on an adjacent square. (But it can be blocked there!) Promotes to Spider.
Moves and captures like an orthodox Rook, but not farther away than four steps. Promotes to Octopus.
Moves two steps orthogonally or diagonally, possibly jumping over an occupied square. Cannot capture, but may induce new moves in friendly pieces adjacent to it: these can then jump over it to the diametrically opposite square, or make one step diagonally provided this ends next to the Dervish. These induced moves can both move and capture, but they can never be promotions. Promotes to Harpy.
Moves and captures like an orthodox Bishop, or one step orthogonally. Promotes to Vulture.
Moves and captures like an orthodox King. Moves that would expose the King to capture are illegal. Promotes to Emperor.
Promoted Pawn. Moves and captures one step diagonally or 3 steps orthogonally (jumping over anythin that might be on the two squares in between). In addition it can also capture one square orthogonally.
Promoted Guard. Moves and captures diectly to squares three steps away in one orthogonal dimension, and two steps in the other. (Like a Knight, but one step further diagonally out.)
Promoted Wazir. Moves and captures one or two steps diagonally (possibly jumping over an occupied square). In addition it can capture an adjacent enemy piece by jumping (two steps) over it orthogonally to an empty square.
Promoted Ferz. Moves and captures one or two steps orthogonally (possibly jumping over an occupied square). In addition it can capture an adjacent enemy piece by jumping (two steps) over it diagonally to an empty square (like a King in Checkers).
Promoted Alfil. Moves and captures like an orthodox Bishop.
Promoted Dabbaba. Moves and captures like an orthodox Queen, but not farther than 3 squares away. In addition it can capture an adjacent enemy piece without moving ('rifle capture').
Promoted Stork. Moves and captures as an orthodox Queen.
Promoted Goat. Moves and captures directly to any square in a 5x5 area around it.
Promoted Commoner. Moves and captures like a Knight or a Camel.
Promoted Knight. Moves and captures like an orthodox Rook.
Promoted Camel. Moves and captures directly two steps orthogonally or diagonally (possibly jumping over an occupied square), or like an orthodox Knight.
Promoted Marquis. Moves and captures like a Knight or like a Bishop, but not farther than 4 squares away.
Promoted Priest. Moves and captures like a Knight or like a Rook, but not farther than 4 squares away.
Promoted Wagon. Moves to an empty orthogonally adjacent square, possibly continuing from there like a Bishop in any of the two outward directions for moving or capturing to more distant destinations.
Promoted Chariot. Moves to an empty diagonally adjacent square, possibly continuing from there like a Rook in any of the two outward directions for moving or capturing to more distant destinations.
Promoted Dervish. Moves like a Queen, but no farther than 3 steps away. The Harpy cannot capture, but it induces extra Knight moves on any friendly piece on a square it could have reached with this 3-step Queen move if it had been empty. The induced Knight moves can both move and capture, but they can never be promotions.
Promoted Scirocco. Moves like a King or a Bisop, and captures like a King or a Rook. (So to adjacent squares it can both move and capture.)
Promoted King. Moves and captures one step orthogonally, or two steps in all eight directions (possibly jumping over an occupied square). Moves that would expose the Emperor to capture are illegal.