The river boundary in the chessboard is also called "Chu River Han Boundary". This name may be influenced by the legend of Chu and Han contending and Han Xin playing chess. Legends can't be verified, and most of them are added by later generations. During the Northern and Southern Dynasties, Emperor Wu of the Northern Zhou Dynasty wrote Xiang Jing, and Yu Xin, a writer, wrote Qi Jing Fu and Jin Qi Jing Fu. It shows that chess has had a universal influence in all walks of life. Unfortunately, most of these works have been lost. The Continued Tibetan Scripture records: "Tu Shennong took the sun, moon and stars as images, and in the Tang Dynasty, cows, monks and children were used as chariots, horses, generals, scholars and soldiers with guns, and chess was used instead." According to this record, there were no cannons in chess before the Tang Dynasty, which is consistent with the development of ancient military technology in China. After joining the artillery, chess is similar to modern chess, or it initially became the embryonic form of modern chess.
There are several interesting legends about the origin of China's chess in China ancient literature. First, Shennong originated from the legendary era. For example, Yuan Nianchang's "History of Buddhism" said that Shennong took the sun and stars as an image, and Tang cattle, monks, children's cars, horses, scholars and soldiers replaced them. Second, the Yellow Emperor originated from the legendary era. For example, the preface to Guangxiang Xige written by Huang Bu in the Northern Song Dynasty said that the battle of the Yellow Emperor was to drive away animals and think about the array. The elephant is also a male among wild animals, so the soldiers play it by its name. Thirdly, it originated in Zhou Wuwang, and Xie Ming said it was like a play in the five miscellaneous stories in Hangzhou. According to legend, it was done during the cutting week, otherwise, it was also a strategist of the Warring States period. At that time, the Beggars' Sect was still focused on car fighting. Fourth, it originated in the Warring States Period. The Book of Seclusion said that Zhou said that he had taken the first step of the Yan army, so he used war chess. During the Warring States period, soldiers were all over the world, and people used the image of war as a chess position. Fifth, when it originated from Emperor Wu of the Northern Zhou Dynasty, Taiping Yulan said that Emperor Wu of the Zhou Dynasty acted as an elephant. Ming Luo Qi and Wuyuan said that Emperor Wu of Zhou played chess.