|Drawing of Wan Ren Di in action, from 'Tian Gong Kai Wu (《天工開物》)'.|
Wan Ren Di is a relatively simple weapon that can be cheaply and easily manufactured. It consists of two components: a hollowed clay ball filled with various types of propellants and gunpowders (usually incendiary or poison smoke) and a fuse, as well as a wooden frame box. Alternatively, a wooden barrel with its inside fireproofed with clay can be used instead.
Like Fei Huo Xiang Mo Chui (飛火降魔槌), the bomb does not detonate after being thrown. Instead, the clay ball start spinning inside the wooden frame box (which is used to protect the clay ball from breaking apart during impact) and projecting fire all around it, effectively deny the area to the enemy for an extended period of time.