草船借箭 — “To achieve one's goals by utilizing others' resources or wisdom”

During the Three Kingdoms period, Cao Cao led a large army to conquer Eastern Wu. Sun Quan and Liu Bei formed an alliance to resist Cao Cao. Among Sun Quan's generals was Zhou Yu, a man of great courage and intelligence, but also narrow-minded and jealous of Zhuge Liang's talents.

Because arrows were needed for naval battles, Zhou Yu challenged Zhuge Liang to produce 100,000 arrows within ten days. To Zhou Yu's surprise, Zhuge Liang confidently offered to complete the task in just three days, even signing a military pledge, agreeing to punishment if he failed.

Zhou Yu thought it impossible to make 100,000 arrows in three days, seeing this as an opportunity to eliminate Zhuge Liang. So, he secretly instructed the weapon makers not to prepare enough materials, and at the same time, sent his minister Lu Su to subtly investigate Zhuge Liang's intentions.

When Lu Su met Zhuge Liang, Zhuge Liang said, "I need your help with this. I hope you can lend me 20 boats, with 30 soldiers on each. The boats must be covered with blue canvas, and we'll need over a thousand straw bundles to line both sides of the boats. However, you must keep this matter absolutely secret from Zhou Yu." Lu Su agreed and prepared everything as Zhuge Liang requested.

Two days passed without any visible activity. On the third day, around the fourth watch (pre-dawn), Zhuge Liang secretly invited Lu Su to board the boats, saying they were going to 'collect' arrows. Lu Su was very puzzled.

Zhuge Liang ordered the boats to be tied together with ropes and sail towards the opposite bank. That day, the river was enveloped in a dense fog, making it impossible to see people across the water. As the boats approached Cao Cao's naval camp, Zhuge Liang commanded them to line up, and ordered the soldiers to beat drums and shout.

Cao Cao, believing the enemy was attacking and fearing an ambush due to the thick fog, dispatched 6,000 archers to shoot arrows into the river. Arrows rained down like raindrops, striking the straw bundles. After a while, Zhuge Liang ordered the boats to turn around, allowing the other side to collect arrows.

As the sun began to rise and the fog started to dissipate, Zhuge Liang commanded the boats to quickly return. By then, the straw bundles on both sides of the boats were densely packed with arrows, with each boat collecting at least five to six thousand arrows, totaling well over 100,000.

When Lu Su recounted the story of how they 'borrowed' the arrows to Zhou Yu, Zhou Yu sighed and exclaimed, "Zhuge Liang possesses divine stratagem and calculation; I am truly no match for him."