What does it mean to draw lots at the beginning of the movie "Man Jiang Hong"?

In order to find the assassin. According to the plot of "Man Jiang Hong", at the beginning of the film, the Guards discovered that the Ambassador of Jin had been stabbed. In order to find the assassin, the deputy commander arrested all the suspects and began to draw lots. The length of the stick drawn from his hand roughly determines life or death. "Man Jiang Hong" is a suspense comedy film in costume, directed by Zhang Yimou and starring Shen Teng, Zhang Yi, Lei Jiayin and Yun-peng Yue. It was released in Chinese mainland on June 22nd, 2023.