A game tool or gambling device is a three-dimensional small square, with six sides engraved at five or six points on 1234, and some places are called dice. The current dice have two color points, that is, one point and four points are red, while the rest are black, and the color changes are related to the emperor. Legend has it that Tang Minghuang and Yang Guifei both love dice games. When it was Tang Minghuang's turn to roll dice, only when the two dice were four points could they win Yang Guifei, when the emperor turned, he kept shouting "double four". When the dice stopped, there were two four points. When Tang Minghuang saw this situation, he thought it was auspicious. He ordered the eunuch Gao Lux to paint all four points of the dice into scarlet, and later painted a little red on the corresponding side of the four points, this said that the people have followed the example and have been circulating so far.
The most important and influential form of Bo opera in ancient China was rolling dice. The dice were produced in different shapes at the earliest, with various lettering on them, and later they were unified into squares or rectangles. The first, second, third and fourth points were engraved, and the red and black colors were different.