Dai dai shogi

Dai dai shōgi (大大将棋 'huge chess') is a large board variant of shogi (Japanese chess). The game dates back to the 15th century and is based on the earlier dai shogi. Apart from its size, the major difference is in the range of the pieces and the "promotion by capture" rule. It is the smallest board variant to use this rule. Because of the terse and often incomplete wording of the historical sources for the large shogi variants, except for chu shogi and to a lesser extent dai shogi (which were at some points of time the most prestigious forms of shogi being played), the historical rules of dai dai shogi are not clear. Different sources often differ significantly in the moves attributed to the pieces, and the degree of contradiction (summarised below with the listing of most known alternative moves) is such that it is likely impossible to reconstruct the "true historical rules" with any degree of certainty, if there ever was such a thing. It is not clear if the game was ever played much historically, as the few sets that were made seem to have been intended only for display.

The objective is to capture the opponent's king. Unlike standard shogi, pieces may not be dropped back into play after being captured.

Relatively few pieces promote (or demote) in dai dai shogi. A few pieces (*asterisked) only appear upon promotion. Piece Kanji RōmajiAbbrev. Promotes to Jeweled general 玉将 gyokushō K 玉 — King general 王将 ōshō K 王 — Angry boar 嗔猪 shincho AB 猪 — Bishop 角行 kakugyō B 角 — Blind monkey 盲猿 mōen BM 猿 mountain witch Blue dragon 青龍 seiryū BD 青 — Cat sword 猫刄 myōjin CS 猫 dragon horse Copper general 銅将 dōshō C 銅 — Dove 鳩槃 kyūhan Do 鳩 — Dragon horse 龍馬 ryūme DH 馬 — Dragon king 龍王 ryūō DK 竜 — Eastern barbarian 東夷 tōi Ea 東 lion Enchanted badger 変狸 henri EB 狸 dove Enchanted fox 変狐 henko EF 狐 she devil Evil wolf 悪狼 akurō EW 狼 — Ferocious leopard 猛豹 mōhyō FL 豹 — Flying dragon 飛龍 hiryū FD 龍 dragon king Flying horse 馬麟 barin FH 麟 queen Fragrant elephant 香象 kōzō FE 象 — Free demon 奔鬼 honki Fr 鬼 — Free dream eater 奔獏 honbaku FT 獏 — *Furious fiend 奮迅 funjin FF 迅 — Gold general 金将 kinshō G 金 — Golden bird 金翅 kinshi GB 翅 — Great dragon 大龍 dairyū GD 大 — *Great elephant ‡ 大象 taizō GE – — Hook mover 鉤行 kōgyō HM 行 — Howling dog 𠵇犬 † kiken HD 𠵇 — Iron general 鉄将 tesshō I 鐵 — Kirin 麒麟 kirin Kr 麒 great dragon Lance 香車 kyōsha L 香 — Left chariot 左車 sasha LC – — Left general 左将 sashō LG – — Lion 獅子 shishi Ln 獅 furious fiend Lion dog 狛犬 komainu LD 狛 great elephant ‡ Long nosed goblin 天狗 tengu Lo 天 — *Mountain witch 山母 sambo MW 母 — Neighboring king 近王 kinnō NK 近 standard bearer Northern barbarian 北狄 hokuteki No 北 fragrant elephant Old kite 古鵄 kotetsu OK 古 long nosed goblin Old rat 老鼠 rōso OR 鼠 wizard stork Pawn 歩兵 fuhyō p 歩 — Phoenix 鳳凰 hōō Ph 鳳 golden bird Poisonous snake 毒蛇 dokuja Po 蛇 hook mover Prancing stag 踊鹿 yōroku PS 鹿 square mover Queen 奔王 honnō Q 奔 — Racing chariot 走車 sōsha Ra 走 — Reverse chariot 反車 hensha Rv 反 — Right chariot 右車 usha RC – — Right general 右将 ushō RG – — Rook 飛車 hisha R 飛 — Rushing bird 行鳥 gyōchō RB 鳥 free demon Savage tiger 猛虎 mōko ST 虎 — She devil 夜叉 yasha SD 叉 — Side mover 横行 ōgyō SM 横 — Silver general 銀将 ginshō S 銀 — Southern barbarian 南蛮 namban So 南 white elephant Square mover 方行 hōgyō Sq 方 — Standard bearer 前旗 zenki SB 前 — Stone general 石将 sekishō St 石 — Vertical mover 竪行 shugyō VM 竪 — Violent bear 猛熊 mōyū VB 熊 — Violent ox 猛牛 mōgyū VO 牛 — Water buffalo 水牛 suigyū WB 水 free dream eater Western barbarian 西戎 seijū We 西 lion dog White elephant 白象 hakuzō WE – — White tiger 白虎 byakko WT – — *Wizard stork 仙鶴 †† senkaku WS 仙 — Wood general 木将 mokushō W 木 —

† The first kanji of Howling Dog may not appear in some fonts. It is a combined 口 and 奇. ‡ The great elephant is mentioned as the promoted lion dog in the Shōgi Rokushu no Zushiki, but not in the other two Edo era sources, when the lion dog does not promote. †† The second character in 'wizard stork' is not present in most fonts: it should be 而 atop 鷦
The queen could also be abbreviated FK (for free king) and the kirin as Ky (for kylin).

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 not literally correct.) A move consists of moving a piece on the board and potentially promoting the piece. Each of these options is detailed below.

Unusually for a large board shogi variant, only a minority of pieces (21 of 64) are able to promote. The rule for promotion in these larger games is different from smaller board variants. A piece promotes at the end of its first capturing move. Promotion has the effect of changing how the piece moves (see the table above for what each piece promotes to), and is effected by turning the piece over after it moves, revealing the name of its promoted rank. Promotion for pieces able to do so is both compulsory and permanent. This is very different from smaller shogi variants, where pieces promote when they cross a promotion zone (the enemy camp), and where promotion is optional. The dots on the dai dai shogi board that would represent promotion zones in other games only function as placement guides for the initial setup of the two camps. Most promoting pieces promote to a piece that exists in the initial setup of the board. However, such a promoted piece cannot then promote a second time as its namesake does. For example, a lion promotes to a furious fiend. However, while an eastern barbarian promotes to a lion on its first capturing move, it does not further promote to a furious fiend on its second. Rather, it remains a lion for the rest of the game. This should be obvious from the game pieces, which only have two sides. If a piece which is only able to move forward (a pawn, lance, stone general, wood general, or iron general) reaches the far rank without promoting, it is unable to move further and must remain there until captured. The promoting pieces appear on the 2nd, 3rd, and 4th ranks of the initial setup. Pieces on the middle three files or the edge file do not promote. Most promoting pieces stand close to their promoted versions in the initial setup.

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 lion, lion dog, and furious fiend are exceptions, in that they do not move, or are not required to move, in a straight line. 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, stone general, wood general, and iron general. 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:

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.)

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).

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, lion dog, kirin, phoenix, and poisonous snake.

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 hook mover and long nosed goblin (tengu) 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.

The lion, lion dog, and furious fiend have sequential multiple capture abilities, called "lion moves". The details of these powerful moves are described for the lion and lion dog, below.

A player may not make a move if the resulting position is one that has previously occurred in the game with the same player to move. This is called repetition (千日手 sennichite). Note that certain pieces have the ability to pass in certain situations (lions, lion dogs, and furious fiends). Such a pass move leaves the position unchanged, but it does not violate the repetition rule, as it will now be the turn of the other player to move. Of course, two consecutive passes are not possible, as the first player will see the same position as before. However, evidence from chu shogi problems suggests that this at least does not apply to a player who is in check or whose pieces are attacked, as otherwise one could win via perpetual check or perpetual pursuit. The modern chu shogi rule as applied by the Japanese Chu Shogi Association (JCSA) is as follows, and presumably dai dai shogi should be similar. If one side is making attacks on other pieces (however futile) with his moves in the repeat cycle, and the other is not, the attacking side must deviate, while in case of checking the checker must deviate regardless of whether the checked side attacks other pieces. In the case of consecutive passes, the side passing first must deviate, making turn passing to avoid zugzwang pointless if the opponent is in a position where he can pass his turn too. Only the fourth repetition is forbidden by these rules. If none of these are applicable, repetition is a draw.

When a player makes a move such that the opponent's king could be captured on the following move, the move is said to give check to the king; the king is said to be in check. If a player's king is in check and no legal move by that player will get the king out of check, the checking move is also a mate, and effectively wins the game.

A player who captures the opponent's sole remaining king or prince wins the game. Thus a player who is checkmated or stalemated will lose. In practice this rarely happens; a player will resign when loss is inevitable and the king will be taken on the opponent's next move (as in International Chess) because of the tradition that it is seen as an embarrassment to lose. The very artificial situation of a smothered stalemate, where no moves are possible (even those that would expose the king), is not covered in the historical sources. On their pages for chu shogi and dai shogi, The Chess Variant Pages rule this as a loss for the stalemated player, for definiteness. A player who makes an illegal move loses immediately. (This rule may be relaxed in casual games.)

The method used in English language texts to express shogi moves was established by George Hodges in 1976. It is derived from the algebraic notation used for chess, but differs in several respects. Modifications have been made for dai dai shogi. A typical example is P 8g. The first letter represents the piece moved (see above). Promoted pieces have a + added in front of the letter. (e. g., +BM for a mountain witch, or promoted blind monkey). The designation of the piece is followed by a symbol indicating the type of move: for an ordinary move or x for a capture. Next is the designation for the square on which the piece lands. This consists of a number representing the file and a lowercase letter representing the rank, with 1a being the top right corner (as seen from Black's point of view) and 17q being the bottom left corner. (This method of designating squares is based on Japanese convention, which, however, uses Japanese numerals instead of letters. For example, the square 2c is denoted by 2三 in Japanese.) If a lion captures by 'igūi’, the square of the piece being captured is used instead of the destination square, and this is preceded by the symbol '!'. If a double capture is made, than it is added after the first capture. If a capture mandates the player to promote the piece, then a + is added to the end to signify that the promotion was taken. For example, CSx7c+ indicates a cat sword capturing on 7c and promoting. In cases where the above notation would be ambiguous, the designation of the start square is added after the designation for the piece in order to make clear which piece is meant. Moves are commonly numbered as in chess.

These descriptions are taken from Japanese Wikipedia, which references the Edo era publications 象戯図式 Shōgi Zushiki (SZ), 諸象戯図式 Sho Shōgi Zushiki (SSZ), and 象棋六種之図式 Shōgi Rokushu no Zushiki (SRZ). The first two are generally though not always in agreement, but the third differs in the case of most pieces which are not found in smaller shogi variants.