Моха Дай Дай Сёги: Ультра-крупная версия японских шахмат

Large variant of shogi

Maka dai dai shōgi (摩訶大大将棋 or 摩𩹄大大象戯 'ultra huge chess') is a large board variant of shogi (Japanese chess). The game dates back to the 15th century and is based on dai dai shogi and the earlier dai shogi. The three Edo era sources are not congruent in their descriptions of the pieces not found in smaller games. Apart from its size and number of pieces, the major difference from these smaller games is the "promotion by capture" rule. A more compact modern proposal for the game is called hishigata shogi. 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 maka 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 or emperor. If a prince is in play, it too must be captured. Unlike standard shogi, pieces may not be dropped back into play after being captured.

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, though the pieces are all the same color.) A move consists of moving a piece on the board and potentially promoting the piece. Each of these options is detailed below.

Most pieces in the game move in a unique manner.

The kings, drunken elephants, blind tigers, ferocious leopards, reclining dragons, Chinese cocks, old monkeys, evil wolves, generals, angry boars, cat swords, coiled serpents, dark spirits, Devas, go betweens and pawns only move one square at a time. If an opponent's piece occupies a square that is a possible destination for the moving piece, the opponent's piece may be captured by placing the moving piece on that square, and removing the opponent's piece from the board. If a friendly piece (that is, a piece controlled by the same player) occupies the square, the moving piece may not move in that direction.

The she devil, wrestler, guardian of the Gods, Buddhist devil, violent ox, flying dragon and old rat can move along a limited number of free squares in certain directions.

The emperor, lion, lion dog, furious fiend, teaching king, Buddhist spirit, kirin, phoenix, donkey and knight jump, that is, they can move over any intervening piece, whether friend or foe.

The queen, dragon king, dragon horse, chariots, rook, bishop, side flier, movers and lance can move any number of squares 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 square, and removing it from the board. 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 Capricorn can move any number of squares along a straight line, then any number of squares along a perpendicular straight line limited by the edge of the board. If an opponent's piece intervenes, it may be captured by moving to that square, and removing it from the board. 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. Although they have the ability to move in two directions in one move, they are not required to.

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

The pawn, lance, stone general, iron general, and knight can only move forward. Therefore, if one reaches the furthest rank (or the penultimate rank in the case of the knight), it is unable to move further, it must remain there until captured. Pieces move 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, ×). The lion, knight, and furious fiend are exceptions.

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, furious fiends, teaching kings, and Buddhist spirits). 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 maka 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, emperor or prince (sole one in play) could be captured on the following move, the move is said to give check to the king, emperor or prince; the king, emperor or prince is said to be in check. If a player's king, emperor or prince is in check and no legal move by that player will get the king, emperor or prince out of check, the checking move is also a mate, and effectively wins the game. If a player has both a king (or emperor) and prince in play, then the player need not move only one out of check. Recall that an emperor can only capture a royal piece if that royal piece is unprotected. (Capturing non royal protected pieces is legal, just almost always a very poor move.) This prohibition applies even if the opponent's last royal piece is being captured: here "protected" means that the opponent could recapture if we ignore that he has just lost his last royal.

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 maka 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., +OM for a mountain witch (promoted old 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 19s 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 or triple capture is made, then it is added after the first capture. If a move entitles the player to promote the piece, then a + is added to the end to signify that the promotion was taken, or an = to indicate that it was declined. For example, CSx7c= indicates a cat sword capturing on 7c without 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.

Sean Humby created a variant of maka dai dai shogi called Hishigata shogi. It was motivated by criticisms that maka dai dai takes a very long time to finish, and that the more interesting pieces have little opportunity for play. The only difference is in the setup, which places the opposing pieces close together and leaves the armies' rear flanks exposed, though Humby recommends that the teaching king be played as the weaker Western variant (as a queen), probably referring to the single alternative offered by Sean Evans' ShogiVar software, which is Queen plus 3 step King with full lion power, no longer believed to be the correct move by anyone.

There are some minor attempts to revive maka dai dai shogi in Japan, with a few rule changes. This revived form of the game is called maka dai shogi. The SZ and SSZ description of the furious fiend (lion + lion dog) is followed. The kirin and phoenix promote to the lion and queen, as in chu shogi. Promotion becomes mandatory on capture, but capturing a Deva or dark spirit does not result in promotion to teaching king or Buddhist spirit respectively. Only capturing the promoted forms of these pieces has that result. The blind bear's move is changed to FsW (one square in any direction but directly forward or backward), making it consistent with the free bear (which moves as shown here with no forward diagonal jump). The "free" pieces resulting from promotion have been changed to "ski sliders" (skipping the first two squares before sliding, similar to the picket in Tamerlane chess), and many of the limited range pieces have been changed to cannon like hoppers that jump to the furthest square in their range, capturing any enemy pieces they leap over. The donkey loses its vertical stepping move and the knight has become a forward only alfil. Many other minor changes are present: for example, the angry boar is now frlW and the old rat is fWbF.

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.