Records of the Three Kingdoms
Wang Ping, courtesy name Zijun, was from Dangqu in Baxi. He began in Cao Cao’s army. In 219, during the fight for Hanzhong, he joined Liu Bei. He could read little. Documents were read aloud to him. Once he gave an order he did not change it.
In 228 at Jieting he was Ma Su’s deputy. Ma Su wanted to leave the water and camp on the hill. Wang Ping argued against it repeatedly. Ma Su refused. In the rout the thousand men under Wang Ping beat drums and held. Zhang He suspected an ambush and did not press the pursuit. Zhuge Liang trusted Wang Ping after that. He later held Hanzhong and met Wei attacks with a steady defense. He died of illness in 248. Chen Shou says he recognized scarcely ten characters, and that he was loyal, brave, and exact in his post.
Romance of the Three Kingdoms
In the novel Wang Ping is one of the few clear heads at Jieting. He asks to camp at the road mouth, is dismissed, and leads his own force. After the defeat he gathers the remnants so the loss is not the whole army.
Later he is often the steady officer beside Jiang Wei. The book uses him to set off Ma Su’s self-confidence.
Reference: Wikipedia · Wang Ping