Guan Lu (209–256),[a] courtesy name Gongming, was a diviner who lived during the late Eastern Han dynasty and Three Kingdoms period of China.

One of Wang Ji's other guests said that his wife was suffering from severe headaches while his son felt pain in his heart.

Guan Lu used the casting lots method and told them that there were two dead bodies buried in the west corner of the main hall and that a wall had been built across them.

Wang Ji then ordered his men to start digging and they found two badly decomposed bodies fitting exactly the description given by Guan Lu.

Guan Lu sensed an aura of death around Zhao Yang and predicted that he would die within three days, so he advised him on how to avoid his unfortunate fate.

The two men, who were apparently deities in charge of deciding people's lifespans, then told Zhao Yang to go back to Guan Lu and warn him that if he attempted to meddle with the ways of fate again, he would suffer punishment from Heaven.

Guan Lu also cast lots to predict the lives of Deng Yang and He Yan, two officials who served in the state of Cao Wei during the Three Kingdoms period.

After discussing this conversation with his uncle, Guan Lu then said: "Deng Yang's gait is that of one whose sinews are loosed from his bones, and his pulse is unsteady.

Soon afterwards, both Deng Yang and He Yan met their ends in the aftermath of the Incident at the Gaoping Tombs in February 249, just as Guan Lu predicted.

As a result, Guan Lu became famous for being one of the most skilled diviners in his time, but there were others who saw him as a mad man.