The authoritative historical source on Guo Jia's life is the Records of the Three Kingdoms (Sanguozhi), which was written by Chen Shou in the third century.

In the fifth century, Pei Songzhi annotated the Sanguozhi by incorporating information from other sources to Chen Shou's original work and adding his personal commentary.

Some alternative texts used in the annotations to Guo Jia's biography include: Fu Zi, by Fu Xuan; Wei Shu (Book of Wei), by Wang Chen, Xun Yi and Ruan Ji; Shiyu (Accounts of this Generation), by Guo Song.

Guo Jia was from Yangzhai County (陽翟縣), Yingchuan Commandery (潁川郡), which is in present-day Yuzhou, Henan.

Since reaching adulthood at around the age of 19, Guo Jia had been travelling around the country and befriending members of the scholar-gentry and other talented persons.

When he was 26, he served in the Han government as a minor official in the office of the Minister over the Masses (司徒).

[Sanguozhi zhu 1] Guo Jia once travelled to Hebei to meet Yuan Shao, an influential warlord who controlled most of northern China at the time.

He focuses too much on unnecessary details and neglects the main points; he likes to listen to many ideas but is indecisive.

Lü Bu lost three battles and retreated to Xiapi (下邳; present-day Pizhou, Jiangsu).

Now, we should take advantage of this situation, when the morale of Lü Bu's forces is low and when Chen Gong has yet to think of a solution, to press on a fierce attack and we'll achieve victory."

[Sanguozhi 4][Sanguozhi 5] The Fu Zi recorded another piece of advice Guo Jia gave to Cao Cao during the Battle of Xiapi: "In the past, Xiang Yu never lost any of the over 70 battles he fought in, but once the tide turned against him, he ended up in death and destruction.

Lü Bu has lost three consecutive battles and his army's morale is low and his defences are weakening.

Therefore, it's imperative that you carefully consider the consequences of ruining your good reputation for the sake of eliminating one man who poses a threat to you."

[Sanguozhi zhu 18] The Chronicles of Huayang stated that following Lu Bu's defeat at Xiapi.

[2] Between 194 and 199, the warlord Sun Ce embarked on a series of conquests in Jiangdong and seized control of most of the territories in the region.

Besides, Sun Ce is overly confident and is unprepared, so even though he has thousands of troops, the situation is not much different from him setting out to conquer the Central Plains all by himself.

Guo Jia's prediction came true as Sun Ce was assassinated by the followers of Xu Gong (a commandery administrator he killed earlier) before he could even carry out his plan.

He felt that it was purely coincidental that Sun Ce was assassinated in the same year he was planning to attack Xu.

[Sanguozhi zhu 20] However, Pei Songzhi commented that Guo Jia was not the one who pointed out Yuan Shao's weakness and suggested to launch a swift attack on Liu Bei.

With advisers like Guo Tu and Pang Ji to assist the Yuans, internal conflict will definitely break out between them.

In recognition of his contributions, the Han imperial court enfeoffed Guo Jia as the Marquis of Weiyang Village (洧陽亭侯).

If you abandon the campaign and head south instead, the Wuhuan and Yuan Shao's former followers might rally the support of the people in northern China, who are likely to respond to their call.

When that happens, the attention of Tadun (a Wuhuan chieftain) will be aroused and he may think of attacking you, and by then we would have lost Qing and Ji provinces.

Why don't we leave the heavy baggage behind and send our light forces to take a shortcut and launch a surprise attack?"

[Sanguozhi 10] Guo Jia was known for his deep foresight, which allowed him to accurately predict the outcomes of events.

[Sanguozhi 16] Guo Yi served as a Literary Scholar of the Crown Prince (太子文學) in the state of Cao Wei during the Three Kingdoms period and died relatively early like his father before him.

Guo Chang was known for his brilliance and he served as a Regular Mounted Attendant (散騎常侍) in the Cao Wei state during the Three Kingdoms period.

If you attack them, they will unite to resist you and you cannot overcome them quickly; if you do not move, Gongsun Kang and the Yuans will fight each other, and this is definite.

"[3] Guo Jia is first introduced as a playable character in the Xtreme Legends version of the seventh instalment in Koei's Dynasty Warriors video game series.

Guo Jia is the protagonist of the manga Ouja no Yuugi (王者の遊戯, The Game of Kings) by Iori Tabasa (緒里 たばさ).