The Wuzi 吳子 "Master Wu" is one of the ancient Chinese military writings. The book is attributed to Wu Qi 吳起, a general of the states of Lu 魯 and Wei 魏 and during the Warring States period 戰國 (5th cent.-221 BCE). He took part in campaigns against the state of Qin 秦 and the conquest of the state of Zhongshan 中山. Later on he became a minister in Chu 楚 and undertook some administrative reforms under the reign of King Dao 楚悼王 (r. 401-381). During a rebellion upon the death of the king Wu Qi was killed. During the next century his book was as widespread as the writings of Master Sun, the Sunzi bingfa 孫子兵法. During the Han period 漢 (206 BCE-220 CE) the book Wuzi had 48 chapters, and during the Tang period 唐 (618-907) the bibliographic records speak of only one juan "scroll". The received book is thus a collection of surviving chapters. Since the Song period 宋 (960-1279), when the Wuzi was included into the canon of the Seven Military Classics (Wujing qishu 武經七書), six chapters are known, included in two juan.
In 33 articles the Marquesses Wen 魏文侯 (r. 424-387) and Wu 魏武侯 (r. 386-371) of Wei ask Master Wu questions about strategy. The questions are not related thematically, and some are identical to phrases found in the military treatise Liutao 六韜. Therefore some modern scholars, like Yao Jiheng 姚際恒 and Guo Moruo 郭莫若 thought it was a forgery. Others, mainly the Ming period 明 (1368-1644) scholar Hu Yinglin 胡應麟, saw it as a loose collection of military thought compiled under the name of Wu Qi during the Warring States period.
The book Wuzi joins interal politics with warfare. A ruler has to exhibit a benevolent government, involving the virtue of civilization (wende 文德). This will strengthen the state because the peasantry, which provided the main source to fill the infantry units, will pay enough taxes, nourish the state, and is idealiter willing to contribute to the war against an inimical state. Able advisors and generals will not leave the country but dedicate themselves to a ruler who estimates his counsellors and commanders. Frugality is also necessary because the funds can be invested in defense and the welfare of the people. The army will thus be disciplined and not harass the own population.
That army will be victorious which puts much effort into the training of its troops. In peacetime soldiers will thus stick to discipline, in wartime they will be imtimidating to the enemy, the advancing line will not be broken, and retreating lines can not be battered, if only exercise is done sufficiently. Each unit has to include experienced and brave veterans that will stimulate their comrades. Tall persons are to be used for the crossbow units, and smaller ones for the halberd files. A commander has thus to select carefully whom he can employ in the right position. Units should be composed of persons from the same village, which strengthens their comradeship. Clever and experienced persons shall train small groups, which then will join and exercise together, until the whole army is able to exert successful movements on the battlefield.
Commands have to be clarified to avoid misunderstanding. Rewards and punishments have to be applied justly and only if needed. This will raise the fighting spirit of the troops, just like the paradigm that generals and officers have to display towards their subordinated: They share all hardships of warfare with their troops, so that soldiers are willing to fight or to sacrifice themselves.
War has always to be waged according to circumstances. The natural conditions, the population, the size and strength of the armies of each one of the Warring States are, the Wuzi says, different, and attacks on each of them have to be made in a different way. The book gives advice how to attack the states of Qi 齊, Qin, Chu or Yan 燕. A thorough reconnaissance is the best preparation for war without the necessity to ask the diviners. The Wuzi enumerates different cases in which the army has to operate differently, according to the situation. Quick attack can sometimes be the best receipt, but is not always recommendable. A good commander is also able to apply various fighting techniques, like attacking the infantry body, or the elite troops of the enemy, to engage in narrow valleys, to fight on water or with water, or to besiege an enemy. The Wuzi is the earliest military book mentioning horse breeding for the cavaly corps. It also gives a few examples of how to apply cavalry in attacks.
In ancient times the Wuzi was almost as important for military strategists like the Sunzi. Both books are often mentioned together and termed Sun-Wu bingfa 孫吳兵法 "The military strategies of Sun and Wu".
Two ancient commentaries by Jia Xu 賈詡 and Sun Qiao 孫鐈 from the Three Kingdoms period 三國 (220-280), are lost. Shi Zimei's 施子美 Wujing qishu jiangyi 武經七書講義 from the Jin period 金 (1115-1234) and Liu Yin's 劉寅 Wujing qishu zhijie 武經七書直解 from the late Qing period 清 (1644-1911) contain commentaries to the seven military classis, including the Wuzi. The Wuzi is also included in the collectaneum Xu guyi congshu 續古逸叢書.
There is a complete English translation by Ralph D. Sawyer (1993), The Seven Military Classics of Ancient China, Boulder: Westview.
Li Ling 李零 (1992). "Wuzi 吳子", in: Zhongguo da baike quanshu 中國大百科全書, Zhongguo lishi 中國歷史, vol. 3, p. 1240. Beijing/Shanghai: Zhongguo da baike quanshu chubanshe.
Li Shuozhi 李碩之, Xiang Lusheng 向麓生 (1989). "Wuzi 吳子", in: Zhongguo da baike quanshu 中國大百科全書, Junshi 軍事, vol. 2, pp. 1073-1074. Beijing/Shanghai: Zhongguo da baike quanshu chubanshe.
1. 圖國 Tuguo Planning for the state
2. 料敵 Liaodi Evaluating the enemy
3. 治兵 Zhibing Controlling the army
4. 論將 Lunjiang About the general
5. 應變 Yingbian Responding to change
6. 勵士 Lishi Stimulating the officers