Shogi,
also known as Japanese Chess, is a two-player board
game in the same family as Western Chess and Chinese
Xiangqi, and is the most popular of a family of chess
variants native to Japan. What makes Shogi unique among
them is that a player may take a piece that had been
previously captured and place it again. It is this rule
that makes it the hardest for computer programmers to
beat the highest rated player of Shogi.
