Ko Shogi (Wide Shogi)
Le Kô Shogi (Le Shogi élargi)
Also known as Wide Elephant Chess, this is the most recent of all large Shogi variants. Nevertheless, it is by far the less known and documented. The reason may be that Ko Shogi has very peculiar characteristics which differ notably from other games of this family.
Ko Shogi is played over intersections and not over spaces. The pieces are round and not wedge-shaped. As a matter of fact, Ko Shogi is a Chess game played on a real Go-bang. (Which is not the case of Maka Dai Dai Shogi by the way!).
Also, replacement is not the only way to capture. Pieces can "shoot" as well!
SETUP (per side):
Note that the set-up is not symetric on the 5th rank.
The board is the 19x19 Go-ban using circular pieces on its points. The (90) White pieces are written with black characters. The (90) Black pieces are written with White characters. On the back side of each piece, written in red, is the characters of promotion.
There are 34 sorts of different pieces. They are mainly named from military characters. The "royal" piece is a General whose capture is the goal of the game. If the Middle Army and Banner are still in play, when the General is captured, the game continues. The Middle Army promotes to Master, and acts as the General. But, if both the Banner and General are captured, it does not promote and the game is over.
The six ranks of the starting position form the promotion zones. Captured pieces are removed from the game, there is no drops.
Apparently several pieces can "shot", i.e. they can capture at distance, up to five an enemy piece without moving from their position. They cannot shot a piece which is beyond another. Two pieces, Cannon and Cannon Chariot, can even shot friend and foe pieces at once. Then, there is a clearly distinction between capture and shoot. Capturing is done by occupying the position of the enemy piece. Shooting is done after a move through vacant points, without moving from the destination point, the piece remains on the position and the enemy at a distance is removed.
Other pieces have their move which can be split into two parts. They can change direction and capture on each parts. Also, it is possible to stop on the first part.
Indeed, some promotion rules are complicated : a piece which captures either the General, Middle Army or Banner can then promote whether or not it is in the promotion zone. A piece which captures either the Wrestler, Dragon Awakening, Summoning Tremble or Thundering Lightning can advance one point if this immediately results in its promotion. The Horse Soldier promotes when it captures the French Wolf Table. When the Scribe becomes the Master-at-Arms, Forward Defense and the Rearguard promote simultaneously.
The complete rules are not available yet. A Japanese description has been recently transcript and is the object of work by L. Lynn Smith, Lex Kraaijeveld and Gregory Sears.
More will be posted here if the reconstruction work by experts progresses.
HISTORY and recent developments:
Developed from Go, it can be considered as a form of Shogi. Although, it is a Shogi of an unusual nature. Ko (or Wide) Shogi is said to have been invented by the Confucian scholar Ogyu Sorai (1666-1728) apparently as a conscious derivative of Xiangqi, Chinese chess.
Another name is Chinese and is Wide Elephant Chess, or Yan Xiangqi. The pieces are round and move in ways not seen in Shogi, Japanese chess. It should be mentioned that there is a tradition that the game actually did originate in China, invented by Chao Wuchiu (1033-1110) (=Zhao Buzhi (1053-1110)?).
So Ko Shogi or Yan Xiangqi? In another word, is that game Japanese or Chinese, this is the question. To my (present) opinion, this game has a Chinese flavor, but it is a flavor only. It is true that there are shooting pieces, one is even called a Cannon, and that recalls the Xiangqi's Pao. There are pieces stepping up to 5 points and that also recalls some pieces with limited moves in Qiguo Xiangqi (7-Handed Xiangqi) also played on a Go-ban. However, neither in Xiangqi nor in Qiguo Xiangqi the Cannons, Catapults or Bowmen do not shoot without from far, without moving, like in Ko Shogi.
Personally, I see more resemblance with Tenjiku Shogi which also has "range jumping" pieces moving like Xiangqi's Pao and which has "area move" piece very similar to the multiple move pieces present here. The "royal" piece in Ko Shogi is a General who moves exactly like in Shogi, not with the limited move of Xiangqi nor the Queen-type move of the General in Qiguo Xiangqi. Also, among the Ko Shogi pieces there is a Master who promotes to a Middle Army who in turn, acts as a second General which must also be captured. This is exactly the principle ruling the Drunk Elephant in several large Shogi variants.
The starting arrangement is not symmetric. Non-symmetry is also found in Dai Dai Shogi and Tai Shogi. Finally, the promotion concept is that of several Shogi variants (Shogi, Chu Shogi, Tenjiku Shogi,...). I am not aware of any promotion in Qiguo Xiangqi. Clearly this needs more research.
Many thanks to L. Lynn Smith, Lex Kraaijeveld and Gregory Sears from whom I borrowed all elements presented here.