During the Three Kingdoms period, Sun Quan of Eastern Wu, inheriting his father and elder brother's legacy, already controlled the six commanderies of Jiangdong but was eager to expand his territory further.
One day, he gathered his ministers at court to discuss plans to send an army to attack Yizhou and Zhuya. Seeing no objections from the others, he turned his gaze to Lu Xun, then serving as Grand General and Right Chief Guardian: "Grand General, what do you think?"
Lu Xun calmly replied, "I believe that with the realm still unsettled, achieving our great cause of unification depends most on the people's strength. Now, after years of warfare, the common folk have suffered greatly. Your Majesty labors tirelessly for the state, forgetting sleep and meals, yet sending troops on a distant campaign to Yizhou to fulfill grand ambitions—this is indeed a lofty vision."
Lu Xun paused briefly, then shifted his tone: "But after careful consideration, I see no benefit in this. A thousand-mile raid is fraught with unpredictable risks; our troops, unaccustomed to the terrain and climate, will surely fall ill. Once we reach that barren land, seeking gain will only bring loss, and pursuing profit will only invite harm."
Noticing Sun Quan's expressionless face, Lu Xun pressed his argument further: "Moreover, Zhuyai is a perilous land, its people as uncivilized as beasts. Gaining their people would not help us achieve great deeds, and losing their troops would cost us nothing. Our strength in Jiangdong is already formidable enough to accomplish great things—the key lies in conserving power and waiting for the right moment. In the past, our Lord Huan Wang founded our enterprise with a modest army. Now, Your Majesty has inherited your father and brother's legacy, controlling the vast Jiangdong region. The future holds great promise."
Lu Xun pressed further, "I have heard that to punish traitors and rebels, one needs a strong army, but that army depends on the people's basic work of farming, weaving, food, and clothing. As things stand, war has not even begun, yet the people already look hungry. Therefore, I believe we should let the people rest and recover, ease their taxes, and cultivate their courage for king and country through peaceful production and daily education. If we can do this, then the lands around the Yellow and Wei Rivers can be pacified, and the Nine Provinces unified."
Sun Quan failed to adopt Lu Xun's correct advice and sent troops on a distant expedition to Yizhou. Although they achieved some military victories, overall "the gains did not offset the losses." This idiom, also written as "gains not compensating losses" or "gains not making up for losses," is used to describe situations where the reward does not compensate for the cost.
Source: *Records of the Three Kingdoms*, "Book of Wu: Biography of Lu Xun"
Meaning of the Idiom: Later, the Chinese idiom "得不酬失" came to describe how the reward does not compensate for the cost.