Taikyoku shogi

Taikyoku shōgi (大局将棋 'ultimate chess') is the largest known variant of shogi (Japanese chess). The game was created around the mid 16th century (presumably by priests) and is based on earlier large board shogi games. Before the rediscovery of taikyoku shogi in 1997, tai shogi was believed to be the largest playable chess variant ever. It has not been shown that taikyoku shogi was ever widely played. There are only two sets of restored taikyoku shogi pieces and one of them is held at Osaka University of Commerce. One game may be played over several long sessions and require each player to make over a thousand moves.

Because the game was found only recently after centuries of obscurity, it is difficult to say exactly what all the rules were. Several documents describing the game have been found; however, there are differences between them. Many of the pieces appear in other shogi variants but their moves may be different. The board, and likewise the pieces, were made much smaller, making archeological finds difficult to decipher. Research into this game continues for historical and cultural reasons, but also to satisfy the curious and those who wish to play what could be the most challenging chess-like game ever made. More research must be done however. This article focuses on one likely set of rules that can make the game playable in modern times but is by no means canon. These rules may change as more discoveries are made and secrets of the game unlocked.

Taikyoku shogi is very different from other large-board shogi variants: tenjiku shogi, dai dai shogi, maka dai dai shogi, and tai shogi. The most notable differences lie with the piece movements and their promotions.

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

Two players, Black and White (or 先手 sente and 後手 gote), play on a board ruled into a grid of 36 ranks (rows) by 36 files (columns) with a total of 1,296 squares. The squares are differentiated by marking or color.

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