The Han dynasty 漢 (206 BCE-220 CE) recruited their state officials by a commandery quota system (chaju zhi 察舉制) in which competent "worthies" were recommended by local officials and had to participate in a kind of examination before being appointed to an office. Each commandery (jun 郡) had to fulfil a quota of presenting potential candidates.
Apart from this system, there was a less formal sytem of internal recommendation (zheng-bi zhi 征辟制) which existed in two forms, namely "recruitment on imperial order or invitation" (zhengzhao 征召) and "elevation or appointment by His Majesty" (biju 辟舉, bishu 辟署, bizhao 辟召). Both systems were used to fill the ranks of officials during the Han period, and are therefore mentioned in one expression, "system of quotas and recommendation" (chaju zheng-bi zhi 察舉征辟制).
A good example for the first method was Emperor Wu's 漢武帝 (r. 141-87 BCE) wish to recruit the poet and rhapsodist Mei Sheng 枚乘 (d. 140 BCE), who was already quite old. Being "invited" (pinzhao 聘召, zhengpin 征聘) to serve the emperor, Mei died on his way to the capital. Other examples of dignitaries recruited in this matter were Gong Yu 貢禹 (124-44) or Gong Sheng 龔勝 (68 BCE-11 CE).
Such famous persons were usually informally appointed as advisors in political matters. Some of them even declined, like Yan Guan 嚴光 (39 BCE-41 CE), Xu Zhi 徐稚 (97-168), Huang Qiong 黃瓊 (86-164) or Fa Zhen 法真 (100-188). This was possible because the "recruitment" was legally but a ritual request, and not an imperial order. During the Eastern Jin period 東晉 (317-420), many literati decided not to remain "hidden scholars" (yinju 隱居) and not to serve the state, in spite of "repeated invitations by the government" (sanzheng qibi 三征七辟).
The second method required recommendation of high potentials by eminent officials (ministers, regional governors, governors) and that the candidates might undergo an examination by the emperor (therefore called "officials appointed by the emperor [after recommendation] by administrative institutions", gongfu bishi 公府辟士). In 117, Emperor Wu ordered the Counsellor-in-chief to establish four types of tests (si ke 四科) according to the individual strengths of potential candidates. Emperor Guangwu 漢光武帝 (6 BCE-57 CE, r. 25-57 CE) of the Later Han dynasty 後漢 (25-220 CE) renewed this procedure.
The book Hanguanyi 漢官儀 describes the prerequisite for these four types of test, namely "excellent display of virtues, purity and austerity" (de xing gaomiao, zhi jie qingbai 德行高妙，志節清白), secondly "thorough knowledge of the Classics like an erudite" (xue tong xingxiu, jing zhong boshi 學通行修，經中博士), thirdly "expertise in laws and decretes, ability to pronounce judgments" (ming da faling, zhu yi jueyi 明達法令，足以決疑), and finally "hardness in strategic planning, no fear of challenges" (gangyi duo lüe, yushi bu huo 剛毅多略，遇事不惑).
These descriptions go back to the alleged strengths of Confucius' disciples, namely "virtuous conduct" (you de xing 有德行, able to write biographical inscriptions and dirges, ming lei 銘誄), "rhetorical ability" (neng yanyu 能言語, able to write letters and discourses, shu lun 書論), thorough knowledge of politics (tong zhengshi 通政事, able to write memorials and argumentations, zou yi 奏議), and "clarity in literary matters" (ming wenxue 明文學, able to write poems and rhapsodies, shi fu 詩賦). The reformist usurper Wang Mang 王莽 (r. 8-23 CE) used to focus on these competences in the respective examinations. In this way, the emperors were able to recruit "enlightened scholars of outstanding virtues [and abilities]" (yi de ming shi 異德明士). By using the recommendation system, central-government officials of the Later Han period were able to group their own clients (yuanshu 掾屬) in their staff (muliao 幕僚).
With the introduction of the nine-rank system (jiupin zhongzheng zhi 九品中正制) under the Wei dynasty 曹魏 (220-265), the individual recommendation system was not abolished, but rather supported the new system and allowed officials of distinguished families to recommend their own offsprings and relatives for official positions. It only lost importance with the handover of the appointment system to the Ministry of Personnel (libu 吏部) during the Sui period 隋 (581-618). Yet even under the Song 宋 (960-1279), when the official civil examinations became the normal way for official career, appointments via recommendation by memorial (zoubi 奏辟) or special appointments by imperial order (bichai 辟差, bizhi 辟置) still existed. In some respect, extraordinary appointments were still possible under the Ming 明 (1368-1644) and Qing 清 (1644-1911) dynasties.