Zhao Shi Zhen's Ju Ma San (拒馬傘) and Ruan Pai (軟牌)

Beside improving and designing various advanced firearms, Ming firearm specialist Zhao Shi Zhen (趙士楨) also came out with many innovative ideas to improve the effectiveness of other equipment. Ju Ma San (拒馬傘, lit. 'Horse-repelling umbrella') and Ruan Pai (軟牌, lit. 'Soft shield') were two such creations. Zhao Shi Zhen was well aware of the protective qualities and usefulness of soft fabric shields like Gun Bei (滾被), Ruan Bi (軟壁) and Gang Rou Pai (剛柔牌), but he also knew that flexible protective equipment can be awkward to handle and difficult to deploy, so he designed the aforementioned Ju Ma San and Ruan Pai as portable, convenient, and easy-to-use improvements to existing flexible shields.

Ju Ma San (拒馬傘)

Components of a Ju Ma San, from 'Xu Shen Qi Pu (《續神器譜》)'.

Ju Ma San was a simple flexible shield that consisted of an X-shaped collapsible wooden frame fitted with eight iron nails serving as attachment points for the blanket, as well as a blanket with five built-in gun loops, which was stuffed with cotton and human hair and covered in scales made of cowhide. Ju Ma San served the dual purpose of a stationary shield, primarily designed to protect against deadly Japanese matchlocks, as well as an actual parasol to protect other firearms against the elements. In addition, it could also be turned into a makeshift cheval de frise by stripping the blanket off the wooden frame and utilising the sharp nails on the frame to deter cavalry charge.

Ju Ma San was usually propped up with a simple hoe, although Zhao Shi Zhen also recommended to use a Fei Meng Pao (飛礞砲) as prop if available.

Ruan Pai (軟牌)

Drawing of a Ruan Pai (top) and a Pao Jia/gun rest (bottom), from 'Xu Shen Qi Pu (《續神器譜》)'.

Despite the portability and convenience of Ju Ma San, it could only be set up on relatively flat and spacious ground, limiting its usefulness in rough and hilly terrain. To address this shortcoming, Zhao Shi Zhen devised Ruan Pai, a smaller flexible shield that took up very little space. 

Ruan Pai replaced the X-shaped wooden frame of Ju Ma San with a tripod shaped like an upside down letter L, and cut down the blanket to a narrower size. Unlike Ju Ma San, the blanket was simply hung on, rather than attached to, the tripod.

Arquebusiers shooting from behind Ju Ma San (top) and Ruan Pai (bottom), from 'Xu Shen Qi Pu (《續神器譜》)'.