Study on the Rules of Muromachi Middle Shogi

Abstract

The current rules of Middle shogi are based on the rules handed down in old documents from the Edo period (1603-1867). However, it is quite possible that the rules of Middle shogi played in the Muromachi period (1336-1573) were different from those of the Edo period, by analogy with the entries in the diaries of that period. Considering that Middle shogi was formed by removing exactly 100 pieces from Maka large shogi, it is natural to assume that Middle shogi and Maka large shogi were played under the same rules. In other words, victory or defeat would have been decided not by capturing the king, but by the safe entry of either the Free king or the Lion into the enemy's camp. We have developed a computerized version of Middle shogi that runs under the rules of Maka large shogi, and examined whether the above rules are suitable as a game.