Abagoren Chess {"rising chess"} is said to have originated in medieval Macedonia and West Bulgaria. I found the game described on the website bgchess.hit.bg/bgstart.html {this website no longer exists} along with Bolyar Chess. Some have questioned whether it is a genuine historical variant.

The object is to checkmate the enemy King {or the Emperor, once the King is promoted}. The initial pieces resemble the pieces in F.I.D.E. chess, with the addition of two princes which are placed in front of the two queens. The Princes have the power to move to any adjacent square, or jump to any square two spaces away.

Pieces are restricted to forwards movement unless they are making a capture or until they have been promoted. Even when capturing they are unable to move more than two spaces in any backward direction.

If you capture an unpromoted Rook, Knight, Bishop, Queen or Prince it becomes yours. You may enter a captured piece onto the board to fight on your side. The promoted pieces {Boat & General} and the Pawns are permanently removed if captured.

All pieces must promote on reaching the farthest rank.

• The King promotes to the Emperor, which moves one step in any direction with no restriction on moving backwards. The Emperor can also create new pawns.
• The pawns promote to become a Boat, which slides orthogonally without restriction on backward movement.
• The Princes, Queens, Rooks, Bishops & Knights promote to become a General, which can slide diagonally or move one step orthogonally with out restriction on backwards movement.

Whenever you promote a Pawn to Boat, or promote any of your other pieces to General, you can return the King to any vacant square on the back-rank in the same move.

This rules file comes with a complete description of the rules and three piece sets: Alfaerie graphics, SHaag graphics and Galactic graphics.