Kō shōgi (広将棋 or 廣象棋 'broad chess') is a large-board variant of shogi, or Japanese chess. The game dates back to the turn of the 18th century and is based on xiangqi and go as well as shogi. Credit for its invention has been given to Confucian scholar Ogyū Sorai (1666–1728), who had also described the rules of the game in his book, Kōshōgifu (廣象棋譜).
Rules of the game
Unlike standard shogi, pieces may not be dropped back into play after being captured. (This should be clear from the non-fungible equipment.) Promotion rules are complex, and the fates of several pieces are interdependent.
Objective
The objective is to capture the opponent's commanding pieces: The general, plus, if present, the governor; otherwise, the banner or middle troop.
Game equipment
Two players, Black and White, play on a go board ruled into a grid of 19 ranks (rows) by 19 files (columns) with a total of 361 intersections.
Each player has a set of 90 pieces of 34 different types. The pieces are round and flattened like go stones. In all, the players must remember 65 different moves. The pieces are generally of the same size, though black pieces may be slightly larger than white pieces.
1 General 1 Clerk 1 Staff officer 2 Aides de camp 2 Sumo wrestlers 2 Aides 2 Staff 2 Chiefs of staff 2 Engineers 1 Taoist Priest 1 Spiritual monk 2 Advance guards
1 Middle troop 1 Drum 1 Banner 2 Sentries 2 Millenaries 2 Quartermasters 2 Centuriae 2 Rear guards 1 Frankish cannon 6 Elephants 4 Longbows
4 Crossbows 4 Cannons 8 Cavalrymen 2 Cavalry 6 Pawns 3 Patrol units 6 Shields 3 Shield units 8 Chariots 2 Chariot units 1 Vanguard
Each piece has its name in the form of one or two Japanese characters marked on its face, in white on black stones and in black on white stones. On the reverse side of most pieces are other characters in red; this side is turned up to indicate that the piece has been promoted during play.
Table of pieces
Listed below are the pieces of the game and, if they promote, which pieces they promote to. *Pieces marked with asterisks are not found at setup, and only appear with promotion. Many of the translations into English are suggestions only.
Piece Kanji rōmaji Promotes to Kanji Rōmaji General 将 shō — Clerk 記室 kishitsu *Master at arms 軍師 gunshi Staff officer 参謀 sambō *Banner-and-drum 旗鼓 kiko Aide de camp 親兵 shimpei Quartermaster Sumo wrestler 力士 rikishi — Aide 舎人 shajin *Town brigade 千戸 senko Staff 舎餘 shayo *Village brigade 百戸 hyakko Chief of staff 軍吏 gunri *Vice commander 副司 fushi Engineer 軍匠 gunshō *Poison flame 毒火 dokka Taoist Priest 高道 kōdō *Five-li fog 五里霧 gorimu Spiritual monk 神僧 shinzō *Immaculate light ? 聖燈 shōtō Advance guard 前衝 zenshō *Skyward net 天網 temmō Middle troop 中軍 chūgun *Governor 帥 sui Drum 鼓 ko *Thunderclap 霹靂 hekireki Banner 旗 ki *Flag waver 招揺 shōyō Sentry 護兵 gohei Centuria Millenary 千総 sensō *Dragon ascending 龍驤 ryūjō Quartermaster 把総 hasō *Tiger wing 虎翼 koyoku Centuria 百総 hyakusō *War hawk 鷹揚 yōyō Rear guard 後衝 goshō *Earthward net 地網 chimō Frankish cannon 佛狼機 butsurōki *Chariot of the Gods ? 神機車 shinkisha Elephant 象 zō — Long bow 弓 kyū *Longbow cavalryman 彍騎 kōki Crossbow 弩 do *Crossbow cavalryman 弩騎 doki Cannon 砲 hō *Gun carriage 砲車 hōsha Cavalryman 馬兵 bahei Cavalry Cavalry 騎総 kisō *Winged horse 天馬 temba Pawn 歩兵 fuhyō Patrol unit Patrol unit 歩総 fusō *Commissar ? 都司 toshi Shield 牌 hai Shield unit Shield unit 牌総 haisō *Heavenly fortress 天塁 tenrui Chariot 車 kuruma Chariot unit Chariot unit 車総 shasō Millenary Vanguard 先鋒 sempō *Commissar ? 都司 toshi
Setup
Below is a diagram showing the setup of one player's pieces. The pieces are placed on the intersecting lines of the board and not in the squares. The way one player sees their own pieces is the same way the opposing player will see their own pieces.
+Board layout + + + + + + + + + + + + + + + + + + + + + + + + + + + + VA + + + + + + + + + CU SU CH SP CH SP CH SP CH SU CH SP CH SP CH SP CH SU CU + PU + P + P + P + PU + P + P + P + PU + CA + HS + HS + HS + HS + HS + HS + HS + HS + CA E C SB LB E C SB LB E FW E LB SB C E LB SB C E R FH + Q + DU + SN D MA B SN + DU + Q + FH R FD SM EN CS GH SR WR A SC G PL A WR SR GH CS EN TB FD
+ Legend A - Aide de Camp B - Banner C - Cannon CA - Cavalry CH - Chariot CS - Chief of Staff CU - Chariot Unit D - Drum DU - Millenary E - Elephant EN - Engineer FD - Advance Guard FH - Centuria FW - European Cannon G - General GH - Staff HS - Cavalryman LB - Long Bow MA - Middle Troop P - Pawn PL - Staff Officer PU - Patrol Unit Q - Quartermaster R - Rear Guard SB - Crossbow SC - Clerk SM - Spiritual Monk SN - Sentry SP - Shield SR - Aide SU - Shield Unit TB - Taoist Priest VA - Vanguard WR - Sumo wrestler
Game play
The players alternate making a move, with Black moving first. A move consists of moving a piece on the board and potentially capturing a piece or pieces and promoting a piece or pieces. Each of these options is detailed below.
Movement and capture
An opposing piece is generally captured by displacement: That is, if a piece moves to an intersection occupied by an opposing piece, the opposing piece is displaced and removed from the board. A piece cannot move to an intersection occupied by a friendly piece (that is, a piece controlled by the same player).
Each piece in the game moves in a unique manner. Most pieces move in one of eight prime directions, either orthogonally (that is, forward, backward, or to the side, in the direction of one of the arms of a plus sign, +), or diagonally (in the direction of one of the arms of a multiplication sign, ×). At the beginning of the game the cavalryman and cavalry are exceptions in that they do not move in a prime direction. (The banner and drums, dragon ascending, war hawk, winged horse, and several other pieces are similar, but they only appear with promotion.)
Many pieces are capable of several kinds of movement, with the type of movement usually depending on the direction in which they move. The most common kinds of moves are step, range, shoot, and jump.
Step movers Some pieces can move only one intersection at a time. (If a friendly piece, and sometimes an enemy piece, occupies an adjacent intersection, the moving piece may not move in that direction. Unlike in Go, 'adjacent' means any of eight intersections.)
The step movers at the beginning of the game are the general, aide de camp, aide, staff, chief of staff, engineer, middle troop, drum, banner, sentry, Frankish cannon, long bow, crossbow, shield, and pawn.
Limited range pieces Some pieces can move along a limited number of free intersections along a straight line. Other than the limited distance, they move like range pieces (see below).
The limited range pieces at the beginning of the game are the chariot and the vanguard.
Jumping pieces
Several pieces can jump, that is, they can pass over an intervening piece, whether friend or foe.
The jumping pieces at the beginning of the game are the clerk, staff officer, Taoist priest, spiritual monk, cavalryman, and cavalry.
Ranging pieces
Many pieces can move any number of free intersections along a straight line, limited by the edge of the board. If an opponent's piece intervenes, it may be captured by moving to that intersection, and removing it from the board. A range piece must stop where it captures, and cannot bypass a piece in its way. If a friendly piece intervenes, the moving piece is limited to a distance that stops short of the intervening piece; if the friendly piece is adjacent, it cannot move in that direction at all.
The ranging pieces at the beginning of the game are the advance guard, millenary, quartermaster, centuria, rear guard, elephant, patrol unit, shield unit, and chariot unit.
Shooting pieces
Some pieces can shoot, that is, they can remove a piece from the board a limited distance from their location. Except for the cannon, they cannot shoot an enemy piece if another piece stands between the shooter and its target. The cannon, however, can shoot over such intervening pieces.
It is not clear if a piece must move in order to shoot.
The shooting pieces at the beginning of the game are the Taoist priest, spiritual monk, Frankish cannon, long bow, crossbow, and cannon.
Burn Wherever a burning piece arrives at an intersection, all adjacent enemy and allied pieces are removed from the board, as described below.
The only burning piece is the poison flame, which only appears with promotion.
Immobilize The skyward net and earthward net have the ability to immobilize enemy pieces in their ranging directions.
Multiple capture
The sumo wrestler and cavalry have double-move with double-capture abilities, similar to the 'lion move' in chu shogi. Unlike the lion, they are merely double-move pieces and do not have the ability to bypass a friendly piece occupying the first landing point. Unless stated otherwise below, the multiple moves do not need to be in the same direction and need not all be taken. A second or later move may return a piece to its starting location.
Among the promoted pieces, the master at arms, banner and drums, five-li fog, thunderclap, flag waver, dragon ascending, tiger wing, war hawk, and winged horse have multiple-capture abilities.
The Frankish cannon has a double-kill ability when it shoots.
Movement diagrams
In the diagrams below, the different types of moves are coded by symbol and by color: Blue for step moves, green for multiple capture, red for range moves, and yellow for jumps. Notation □ Jumps directly to this square and stops, bypassing any intervening piece, but generally may not capture with this move with only a few exceptions. ☆ Jumps directly to this square and stops, bypassing any intervening piece, and may capture. ○ Steps a limited number of squares along a straight line, and may capture. Must stop upon capture. ○ Steps a limited number of squares along a straight line, capturing more than once. ● Steps a limited number of squares within an area, changing direction and capturing more than once. ╋ Steps a fixed number of squares within an area, changing direction and capturing more than once; cannot stop until range is exhausted. ☆ Jumps a limited number of times to this square; square may also be reachable with an areal step. ! igui (capture without moving). Counts for two steps. │ Ranges along a straight line, crossing any number of empty squares. Must stop upon capture. ─ ╲ ╱ ─ Ranges in this direction as well as immobilizes enemy pieces in the way. ╲ ╱ ! Shoots the nearest piece in this direction (capture without moving). ‼ Shoots twice in this direction (double capture without moving). * Shoots at one of these squares, by passing any intervening piece (capture without moving). ※ Burns all adjacent enemy and allied pieces wherever it stops.
Individual pieces
Pieces are arranged in this section so that, if they promote, the promoted version is to the right. Piece names with a grey background are present at the start of the game; those with a blue background only appear with promotion. Abbreviations of Kanji names are not official, but for the sake of Layout.