Sho shogi

Shō shōgi (小将棋 'small chess') is a 16th-century form of shogi (Japanese chess), and the immediate predecessor of the modern game. It is played on a 9×9 board with the same setup as in modern shogi, except that an extra piece is placed in front of the king: a 'drunk elephant' that promoted into a prince, which acts like a second king. According to the Sho Shōgi Zushiki, the drunk elephant was eliminated by the Emperor Go-Nara (reigned 1526–1557), and it is assumed that the drop rule was introduced at about the same time, giving rise to shogi as it is known today.

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