Tai shogi

Tai shogi (泰将棋 "tai shōgi" or 無上泰将棋 "mujō tai shōgi" "grand chess", renamed from 無上大将棋 "mujō dai shōgi" "supreme chess" to avoid confusion with 大将棋 "dai shōgi") is a large-board variant of shogi (Japanese chess). The game dates to the 15th century and is based on earlier largeboard shogi games. Before the discovery of taikyoku shogi in 1997, tai shogi was believed to be the largest playable chess variant, if not board game, ever. One game may be played over several long sessions and require each player to make over a thousand moves. It was never a popular game; indeed, a single production of half a dozen game sets in the early 17th century was a notable event.

Like other large-board variants, but unlike standard shogi, the game is played without drops, and uses a promotion-by-capture rule.

Rules of the game

Tai shogi is very similar to other large-board shogi variants: dai dai shogi, maka dai dai shogi, and tenjiku shogi. Where the same pieces are found, they move the same way. The only difference is in how these pieces promote, which is distinct for each shogi variant. The one variant which is an exception to this generalization is the largest, taikyoku shogi, where the moves differ as well.

Objective

The objective of the game is to capture the opponent's emperor and crown prince (or princes). When the last of these is captured, the game ends. There are no rules for check or checkmate; however, in practice a player resigns when checkmated.

Game equipment

Two players, Black and White (or 先手 "sente" and 後手 "gote"), play on a board ruled into a grid of 25 "ranks" (rows) and 25 "files" (columns), for a total of 625 squares. The squares are undifferentiated by marking or color.

Each player has a set of 177 wedge-shaped pieces of 93 types. In all, the players must remember 99 moves for these pieces. The pieces are of slightly different sizes. From largest to smallest (or roughly most to least powerful) they are:

* 1 Emperor
* 1 Crown prince
* 1 Hook mover
* 2 Long-nosed goblins
* 1 Capricorn
* 2 Peacocks
* 2 Soaring eagles
* 2 Horned falcons
* 2 Free kings
* 1 Rushing bird
* 2 Free demons
* 2 Free tapirs
* 2 Water buffalos
* 2 Flying oxen
* 2 Soldiers
* 2 Dragon kings
* 2 Dragon horses
* 1 Lion
* 2 Side chariots
* 2 Rooks
* 2 Bishops
* 2 White horses
* 2 Whales
* 2 Standard bearers
* 1 Vermillion sparrow
* 1 Turtle-snake
* 1 Blue dragon
* 1 White tiger
* 1 Right chariot
* 1 Left chariot
* 2 Side dragons
* 2 Doves
* 1 She-devil
* 1 Golden bird
* 1 Great dragon
* 2 White elephants
* 1 Lion dog
* 1 Wrestler
* 1 Guardian of the Gods
* 1 Buddhist devil
* 2 Golden deer
* 2 Silver hares
* 2 Fierce eagles
* 1 Old kite
* 2 Violent oxen
* 2 Flying dragons
* 2 Old rats
* 2 Enchanted badgers
* 2 Flying horses
* 2 Prancing stags
* 2 Violent bears
* 2 Side movers
* 2 Vertical movers
* 2 Reverse chariots
* 1 Phoenix
* 1 Kirin
* 2 Poison snakes
* 1 Northern barbarian
* 1 Southern barbarian
* 1 Eastern barbarian
* 1 Western barbarian
* 2 Blind bears
* 1 Drunken elephant
* 1 Neighbor king
* 2 Blind tigers
* 2 Blind monkeys
* 2 Ferocious leopards
* 2 Reclining dragons
* 2 Chinese cocks
* 2 Old monkeys
* 2 Evil Wolves
* 2 Angry boars
* 2 Cat swords
* 2 Coiled serpents
* 1 Deva
* 1 Dark spirit
* 1 Right general
* 1 Left general
* 2 Gold generals
* 2 Silver generals
* 2 Copper generals
* 2 Tile generals
* 2 Iron generals
* 2 Wood generals
* 2 Stone generals
* 2 Earth generals
* 2 Go betweens
* 2 Knights
* 2 Howling dogs
* 2 Donkeys
* 2 Ram’s-head soldiers
* 2 Lances
* 25 Pawns

Several of the English names were chosen to correspond to rough equivalents in Western chess, rather than as translations of the Japanese names.

Each piece has its name in the form of two kanji written on its face. On the reverse side of some pieces are one or two other characters, often in a different color (commonly red instead of black); this reverse side is turned up to indicate that the piece has been promoted during play. The pieces of the two sides do not differ in color, but instead each piece is shaped like a wedge, and faces forward, toward the opposing side. This shows who controls the piece during play.

Table of pieces

Listed here are the pieces of the game and, if they promote, which pieces they promote to.

Game play

The players alternate making a move, with Black moving first. (The traditional terms 'black' and 'white' are used to differentiate the sides during discussion of the game, but are no longer literally descriptive.) A move consists of moving a single piece on the board and potentially "promoting" that piece or displacing ("capturing") an opposing piece. Each of these options is detailed below.

Movement and capture

"When the same piece occurs in tai shogi and maka dai dai shogi, it moves and promotes the same way in both. The only exception is the (crown) prince, and the only difference there is its name."

An opposing piece is captured by "displacement": That is, if a piece moves to a square occupied by an opposing piece, the opposing piece is displaced and removed from the board. A piece cannot move to a square occupied by a friendly piece (meaning another piece controlled by the moving player).

Each piece on the game moves in a characteristic pattern. Pieces move either "orthogonally" (that is, forward, backward, left, or right, 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, ×). The emperor, lion, and knight are exceptions at the beginning of the game, in that they do not move, or are not required to move, in a straight line. (The Buddhist spirit and furious fiend are similar, but they only appear as pieces promote.)

If a piece that cannot retreat or move aside advances across the board until it can no longer move, it must remain there until captured. This applies to the pawn, lance, ram’s-head soldier, stone general, wood general, and iron general upon reaching the furthest rank, and to the knight upon reaching either of the two furthest ranks.

Many pieces are capable of several kinds of movement, with the type of movement most often depending on the direction in which they move. The movement categories are:

tep movers

Some pieces move only one square at a time. (If a friendly piece occupies an adjacent square, the moving piece may not move in that direction; if an opposing piece is there, it may be displaced and captured.)

The step movers are the crown prince, drunk elephant, neighbor king, blind tiger, blind monkey, ferocious leopard, reclining dragon, Chinese cock, old monkey, evil wolf, the generals (except the wood general), angry boar, cat sword, coiled serpent, deva, dark spirit, go between, and the 25 pawns on each side.

Limited ranging pieces

Some pieces can move along a limited number (2, 3, or 5) of free (empty) squares along a straight line in certain directions. Other than the limited distance, they move like ranging pieces (see below).

These pieces are the water buffalo, standard bearer, vermillion sparrow, turtle-snake, blue dragon, white tiger, dove, she-devil, golden bird, great dragon, white elephant, lion dog, wrestler, Guardian of the Gods, Buddhist devil, golden deer, silver hare, fierce eagle, old kite, violent ox, flying dragon, old rat, enchanted badger, flying horse, prancing stag, violent bear, the barbarians, and the wood general.

Jumping pieces

Several pieces can "jump", that is, they can pass over any intervening piece, whether friend or foe, with no effect on either. These are the lion, kirin, phoenix, poison snake, donkey, and knight.

Ranging pieces

Many pieces can move any number of empty squares along a straight line, limited only by the edge of the board. If an opposing piece intervenes, it may be captured by moving to that square and removing it from the board. A ranging piece must stop where it captures, and cannot bypass a piece that is 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 are the soaring eagle, horned falcon, free king, rushing bird, the demons, free tapir, water buffalo, flying ox, soldier, dragon king, dragon horse, the chariots, rook, bishop, white horse, whale, standard bearer, vermillion sparrow, turtle-snake, blue dragon, white tiger, side dragon, golden bird, great dragon, white elephant, golden dear, movers, howling dog, ram’s-head solder and lance.

Hook moves (changing tack)

The hook mover, long-nosed goblin, Capricorn, and peacock can move any number of squares along a straight line, as a normal ranging piece, but may also abruptly change tack left or right by 90° at any one place along the route, and then continue as a ranging piece. Turning a corner like this is optional.

The range covered by a hook move is the equivalent of two moves by a rook, or two moves by a bishop, depending the piece. However, a hook move is functionally a single move: The piece cannot capture twice in one move, nor may it capture and then move on. It must stop before an intervening piece (unless it first changes direction to avoid it), and must stop when it captures, just like any other ranging piece. It can only change direction once per move.

Lion moves (multiple captures)

The lion, lion dog, soaring eagle, and horned falcon have sequential multiple-capture abilities, called "lion moves". Among the pieces that only appear with promotion, so do the teaching king, buddhist spirit, and furious fiend. The details of these powerful moves are described for the lion, below.

Individual pieces

"When a piece occurs in both tai shogi and maka dai dai shogi, it moves and promotes the same way."

Emperor (自在)天王 "(jizai) tennō"
*Ranging jump: The emperor can jump to any empty square anywhere on the board.
**However, it can capture a piece only if that piece is unprotected (this rule prevents the game from starting with checkmate).:"Note that since the opposing emperor protects all other opposing pieces on the board, an emperor can only capture after the opposing emperor has been removed from play—unless the opposing emperor moves to an unprotected square, putting itself in check."

Crown prince 太子 "taishi"
*Step: The crown prince can step one square in any direction, orthogonal or diagonal.

:"It may move into or remain in check (not recommended)."

Hook mover 鉤行 "kōgyō"
*Hook move: The hook mover can move any number of free squares along one of the four orthogonal directions, then (optionally) turn 90° and move any number of free squares in a perpendicular orthogonal direction.

Long-nosed goblin 天狗 "tengu"
*Hook move: The "tengu" can move any number of free squares along one of the four diagonal directions, then (optionally) turn 90° and move any number of free squares in a perpendicular diagonal direction; or,
*Step: It can step one square in one of the four orthogonal directions.

Capricorn 摩