Sun Bin was a native of the State of Qi during the mid-Warring States period and a descendant of the legendary military strategist Sun Wu. Orphaned young, he lost his mother at four and his father at nine. As he grew older, he became a disciple of Guiguzi to study the art of war. Studying alongside him was a junior fellow disciple named Pang Juan, who was intelligent and accomplished in his studies but always slightly inferior to Sun Bin due to his lesser natural talent. Sun Bin not only possessed exceptional insight but was also upright and benevolent. Recognizing his extraordinary military aptitude and virtuous character, Guiguzi privately taught him Sun Wu's "Thirteen Chapters on the Art of War." Sun Bin memorized all thirteen chapters in just three days and returned the book to his master. During their apprenticeship, Sun Bin and Pang Juan had a close relationship. However, Pang Juan was narrow-minded and treacherous, though skilled at disguising his true nature. Outwardly kind to Sun Bin, he was secretly deeply jealous of him. Sun Bin, kind-hearted and sincere, treated Pang Juan with genuine goodwill, always regarding him as a good brother.
After studying under Guiguzi for several years, Sun Bin and Pang Juan had greatly improved their knowledge of military strategy and tactics. At that time, King Hui of Wei, following the example of Duke Xiao of Qin, offered generous rewards to attract talented individuals. Pang Juan, originally from Wei and greedy for fame and fortune, was unwilling to continue enduring hardship in the deep mountains, so despite not having completed his studies, he decided to leave the mountains. Sun Bin saw him off, and at their parting, Pang Juan promised Sun Bin that if he gained a high position, he would recommend him to the King of Wei. Sun Bin was deeply moved, and the two bid farewell.
Pang Juan arrived in the State of Wei and tried every means to finally secure an audience with King Hui of Wei. He poured out all his knowledge, speaking eloquently at length about strategies for governing the country, ensuring peace, and commanding armies, even claiming that he could enable Wei to annex the other six states. King Hui of Wei was very pleased upon hearing this and appointed him as Marshal, placing him in charge of Wei's military forces. Although Pang Juan was not as talented as Sun Bin, he was indeed capable. He led the Wei army into battles against neighboring small states, achieving consecutive victories that forced states like Song, Lu, Wei, and Zheng to submit to Wei. Soon, Pang Juan was promoted to Supreme General, becoming a nationally renowned figure in Wei, and King Hui of Wei trusted him even more deeply.
Pang Juan was enjoying a period of great success, but he always harbored a hidden worry in his heart: Sun Bin. He knew well that when it came to military strategy, his own abilities were far inferior to Sun Bin's, and once Sun Bin emerged from seclusion, he would pose a serious threat to Pang Juan's position. However, Pang Juan had also promised Sun Bin that he would recommend him to King Hui of Wei. Just as Pang Juan was tossing and turning with anxiety, unsure of what to do, King Hui of Wei had already learned of Sun Bin's talents from Mozi and ordered Pang Juan to write a letter inviting Sun Bin to come out of retirement. It turned out that Mozi and Guiguzi were close friends, and when Mozi visited Guiguzi, he discovered Sun Bin's outstanding abilities and recommended him to King Hui of Wei. With matters having come to this point, Pang Juan had no choice but to comply.
Upon receiving Pang Juan's letter, Sun Bin felt deeply grateful, so he bid farewell to his teacher and descended the mountain to arrive in the State of Wei. Pang Juan greeted him with a smile on the surface, but inwardly he was very displeased. Soon, King Hui of Wei met Sun Bin and held him in high regard, wanting to appoint him as deputy military commander to share authority over the army with Pang Juan. This stirred secret jealousy in Pang Juan, who least wanted to work alongside Sun Bin, so he suggested that making Sun Bin a deputy, subordinate to himself, would underutilize his talents, and advised the king to first give him the title of guest minister. A guest minister was a position that enjoyed high ceremonial treatment but held no real power. Not wanting to slight Sun Bin, the king adopted Pang Juan's suggestion and even praised Pang Juan's character.
Pang Juan, fearing that Sun Bin's military talents would surpass his own once revealed, secretly plotted to eliminate him. Later, during a casual conversation with Sun Bin, Pang Juan learned that Sun Bin had long lost contact with his relatives in the state of Qi, and so he devised a scheme. He had someone pretend to be a messenger from Qi, who brought Sun Bin a letter supposedly from his cousin, urging him to return to Qi and serve the state. Aware that he was in the state of Wei, Sun Bin politely declined in his reply. Pang Juan then altered the letter to fabricate evidence that Sun Bin was secretly communicating with Qi, and presented it to the King of Wei. Enraged, the king declared Sun Bin guilty of treason, had him arrested, and subjected him to the punishments of having his kneecaps removed (bin punishment) and his face tattooed (qing punishment).
Pang Juan brought Sun Bin to his residence, secretly placed spies to monitor him, and asked him to write down Sun Tzu's The Art of War from memory. Grateful for what he believed was Pang Juan's kindness in not abandoning him, Sun Bin worked day and night to transcribe the text. Later, a servant caring for Sun Bin overheard that Pang Juan planned to starve him to death once the book was finished and relayed this news to Sun Bin. Sun Bin suddenly realized the truth, and reflecting on past events, understood that it was this very man, whom he had regarded as a brother, who had caused his downfall. Filled with pain and hatred, he knew that to take revenge, he must first escape Pang Juan's control, and so he devised a plan.
The next day, Sun Bin began transcribing the art of war again, but as he wrote, his eyes suddenly rolled back, his limbs trembled uncontrollably, and soon he collapsed unconscious. When he came to, he started shouting and raving, alternating between crying and laughing, and flew into inexplicable rages, grabbing the completed manuscript and throwing it into a brazier, even lunging after it himself. The onlookers were horrified and quickly rescued him, then reported to Pang Juan that Sun Bin had gone mad.
Upon hearing the report, Pang Juan rushed to Sun Bin's residence and personally saw him acting wildly and erratically, yet he still refused to believe that Sun Bin had gone mad. So, Pang Juan ordered Sun Bin to be placed in a pigsty. With disheveled hair, Sun Bin crawled and rolled in the muddy water of the pigsty, covering himself entirely with pig manure, yet he alternately cried and laughed. When someone brought him food, he knocked it over and instead grabbed pig manure and put it into his mouth. Only then did Pang Juan begin to believe that Sun Bin had truly lost his mind. However, being naturally suspicious, Pang Juan still had people monitor Sun Bin's actions. They reported that Sun Bin, covered in filth, crawled everywhere—whether in the horse stable or the pigsty—and slept wherever he grew tired. Finally, Pang Juan became convinced that Sun Bin was genuinely insane and gradually relaxed his surveillance over him.
Sun Bin pretended to be insane while looking for an opportunity to escape. It was Mozi who had originally recommended Sun Bin to the King of Wei, and when Sun Bin ended up in such a dire situation, Mozi knew he was being wronged and also realized that Sun Bin was feigning madness to avoid disaster. He informed Tian Ji, a general of the state of Qi, about Sun Bin's predicament and highly praised Sun Bin's talent and resourcefulness. As a result, Tian Ji sent an envoy to the state of Wei to rescue Sun Bin.
One night, an envoy secretly visited Sun Bin and, under the cover of darkness, swapped the real Sun Bin with a decoy, hiding him in his carriage before swiftly leaving the State of Wei. By the time Pang Juan discovered Sun Bin's escape, Sun Bin had already returned to the State of Qi. Upon returning to his homeland, Sun Bin met with General Tian Ji, who greatly admired his talent and kept him in his residence, treating him with the highest respect as an honored guest.
The rulers and ministers of the State of Qi often gambled on horse races for entertainment, dividing the horses into three grades—upper, middle, and lower—and competing in three matches, with the winner being the one who won the most races. Tian Ji's horses were not as good as those of the King of Qi, so he often lost all three matches and felt very discouraged. One time, Sun Bin watched the race and then gave Tian Ji advice to change the order of the horses: use his upper-grade horse against the king's middle-grade horse, his middle-grade horse against the king's lower-grade horse, and his lower-grade horse against the king's upper-grade horse. After the race, Tian Ji won two out of three matches, greatly surprising the King of Qi, as Tian Ji rarely won. Though this was a small matter, it fully demonstrated Sun Bin's resourcefulness. Tian Ji greatly admired him and took the opportunity to recommend him to the King of Qi. The king received Sun Bin and found him to be eloquent with unique insights, truly a remarkable talent, so he addressed Sun Bin as "Master" and held him in high regard.
After Sun Bin escaped, Pang Juan continued to hold military power in the State of Wei, always seeking to enhance his reputation through battlefield achievements. In 354 BCE, Pang Juan led 80,000 Wei troops to attack the State of Zhao, besieging its capital, Handan. Zhao sent messengers to the State of Qi for help. The King of Qi, knowing Sun Bin's military expertise, intended to appoint him as general to lead the army to rescue Zhao. Sun Bin declined due to his physical disability, recommending instead that Tian Ji be appointed as general while he himself served as an advisor. Consequently, the King of Qi appointed Tian Ji as the chief commander and Sun Bin as the military strategist, sending their forces to aid Zhao.
Tian Ji wanted to lead the main army directly to Handan to engage the Wei forces head-on and lift the siege of Zhao. Sun Bin believed that Wei's elite troops were all tied up besieging Zhao, leaving their homeland vulnerable, so he advised Tian Ji to attack Daliang, the Wei capital, which would force the Wei army to turn back to defend itself, thus relieving Zhao's plight while also exhausting the Wei troops and allowing the Qi army to fight at ease. Tian Ji found this strategy excellent, immediately adopted it, and led the Qi army toward Daliang.
With Qi forces pressing the border and the capital Daliang under siege, Pang Juan indeed had no choice but to abandon his attack on Handan and hastily lead his main army back to relieve Daliang. As the Wei army reached Guiling, they fell into a Qi ambush; exhausted from the forced march, the soldiers were routed by Qi forces, and their commander Pang Juan was captured alive. Wei sued for peace with Qi, and Sun Bin, after lecturing Pang Juan, released him back to Wei. Although Sun Bin did not kill Pang Juan, this battle dealt a heavy blow to him. This is the famous strategy of "besieging Wei to rescue Zhao."
More than a decade later, Pang Juan allied with the State of Zhao to attack the State of Han. Unable to withstand the combined assault of Zhao and Wei, Han sent envoys to the State of Qi for help. Within Qi, there were differing opinions—some advocated waiting and watching, while others urged immediate rescue, and neither side could prevail. King of Qi asked Sun Bin for his advice, and Sun Bin proposed a compromise: first agree to Han’s request, letting them fight with all their strength while awaiting reinforcements, then, after both sides were exhausted, send troops to attack Wei. This way, Qi could easily strike the weary Wei army and rescue the beleaguered Han. The King greatly approved of this strategy, and after a year of fighting between Wei and Han, he once again appointed Tian Ji as the chief general and Sun Bin as the military advisor to go to the rescue.
Sun Bin repeated his tactic, leading his troops with Tian Ji to directly attack Daliang, the capital of Wei. Upon hearing that Daliang was under siege, Pang Juan angrily led his army back to the capital. Sun Bin said that the Wei army, relying on its bravery, was eager for battle, and this mindset could be exploited by feigning cowardice to lure the enemy deeper. So he ordered Tian Ji to retreat, reducing the number of cooking stoves each day to create the illusion of a dwindling force.
Pang Juan led his troops back to Daliang, only to find that the Qi army had already withdrawn. As expected, the Wei forces gave relentless chase for three days. On the first day, the Qi camp had one hundred thousand cooking stoves; by the second day, only fifty thousand remained; and by the third day, just thirty thousand were left. Seeing this, Pang Juan believed the Qi soldiers were cowardly and secretly rejoiced, so he pressed forward with his elite troops in hot pursuit.
Sun Bin knew Pang Juan had fallen for the trap, calculated the Wei army's march, estimated they would reach Maling by evening, and set an ambush there.
The Maling Path was a narrow trail situated between two towering mountains, densely wooded and strategically treacherous—easy to enter but difficult to exit, making it an ideal ambush site. Sun Bin ordered trees to be felled to block the road, selected a large tree by the path, stripped a section of its bark, and inscribed on the trunk: "Pang Juan dies beneath this tree!" He then positioned archers on both sides of the Maling Path, instructing them to shoot arrows toward the inscribed tree as soon as a fire was lit beneath it.
In the evening, the Wei army cavalry led by Pang Juan indeed arrived at Maling Road. Soldiers reported that the road ahead was blocked by tangled trees, so Pang Juan hurried forward to inspect. He saw trees lying crisscrossed everywhere, with only a large tree standing upright by the roadside, its bark seemingly bearing writing, so he ordered torches to be lit. As he approached the tree with a torch and just made out the words "Pang Juan dies beneath this tree," he suddenly realized he had fallen into a trap, but it was too late—before he could shout "Retreat," the Qi army unleashed a volley of arrows, and the Wei troops immediately fell into chaos. Knowing defeat was certain and beyond recovery, Pang Juan drew his sword and slit his own throat.
The Qi army pursued and defeated the Wei army, capturing Wei Crown Prince Shen and taking him back to Qi. Sun Bin became widely famous because of this battle.