Original Text
Sun Tzu said: According to the general principles of warfare, there are nine types of terrain: "Dispersed Ground," "Light Ground," "Contentious Ground," "Intersecting Ground," "Hub Ground," "Heavy Ground," "Broken Ground," "Surrounded Ground," and "Deadly Ground." When fighting within one's own territory, it is called "Dispersed Ground." When entering enemy territory but not far, it is called "Light Ground." Ground that benefits the side that occupies it first is called "Contentious Ground." Ground that both sides can easily reach is called "Intersecting Ground." Ground bordering multiple states, where whoever arrives first can gain the support of neighboring allies, is called "Hub Ground." Deep in enemy territory, with many enemy cities behind, is called "Heavy Ground." Mountainous, forested, marshy, or difficult terrain is called "Broken Ground." Ground with narrow access and winding retreat paths, where the enemy can attack with a small force, is called "Surrounded Ground." Ground where fighting swiftly ensures survival, but hesitation leads to annihilation, is called "Deadly Ground." Therefore, do not fight on Dispersed Ground; do not linger on Light Ground; do not attack Contentious Ground forcefully; ensure mutual support on Intersecting Ground without being cut off; actively ally with neighboring states on Hub Ground; seize supplies on Heavy Ground; pass through Broken Ground quickly; devise escape strategies on Surrounded Ground; and fight with all your might on Deadly Ground.
Those who excelled in commanding armies in ancient times could make the enemy's vanguard and rear unable to support each other, their main and auxiliary forces unable to rely on each other, officers and soldiers unable to rescue one another, superiors and subordinates unable to coordinate, and their troops scattered and unable to regroup, or even if regrouped, unable to act in unison. When favorable, they fought; when unfavorable, they refrained. Someone may ask: "If the enemy is numerous and advances in a well-ordered formation, how should we deal with them?" The answer is: "First seize a vital point that the enemy must rescue, and then they will be forced to follow our lead." The principle of employing troops values speed—strike when the enemy is off guard, take paths they do not expect, and attack where their defenses are weak.
The general principle for operating within enemy territory is this: the deeper you penetrate hostile land, the more steadfast your army's spirit becomes, and the harder it is for the enemy to defeat you. Meanwhile, forage from the enemy's fertile fields to ensure ample supplies; take care to rest and avoid overworking the troops, maintaining morale and conserving strength. Deploy forces with cunning strategy so the enemy cannot fathom your strengths, weaknesses, or intentions. Place troops in a desperate situation with no escape, and soldiers will rather die than retreat. Since they no longer fear death, what cannot they accomplish? Thus, the entire army will inevitably fight to the utmost against the enemy. When soldiers are truly trapped in dire straits, they become fearless; with no way out, their resolve solidifies. The deeper they go into enemy territory, the stronger their cohesion becomes. When compelled, they will fight to the death. In such circumstances, the army becomes disciplined without punishment, motivated without encouragement, united without coercion, and obedient without repeated orders. Prohibit superstitious divination in the ranks to dispel doubts, and soldiers will never flee even unto death. Soldiers do not hoard wealth, not because they disdain riches; they set aside thoughts of life and death, not because they wish to die. When battle orders are given, seated soldiers wet their sleeves with tears, and lying soldiers weep profusely. Yet once placed in a hopeless situation, they become as brave as Zhuan Zhu or Cao Gui.
Those skilled in commanding warfare can make their troops respond to each other like the "Shuairan" snake. The Shuairan is a magical snake that lives on Mount Heng. If you strike its head, its tail comes to the rescue; if you strike its tail, its head comes to the rescue; if you strike its belly, both head and tail come to the rescue. Someone asks: "Can an army be commanded as flexibly as the Shuairan snake?" The answer is: "Yes." The people of Wu and Yue are normally hostile to each other, but when they cross a river together in the same boat and encounter a strong wind, they rescue each other as naturally and skillfully as the left and right hands. Therefore, trying to stabilize troops by tying horses' reins and burying chariot wheels to show a determination to fight to the death is unreliable. To make the entire army united in heart and brave as one person depends on effective leadership and governance. To enable both the brave and the timid to fully play their roles lies in skillfully utilizing the terrain. Those adept at using troops in battle can make the entire army join hands and unite like one person, obeying commands, because the objective situation forces the troops to do so.
As a commander, when devising strategies, remain calm, composed, and unfathomably deep; when managing troops, be fair, strict, and orderly. Conceal your plans from the soldiers, keeping them ignorant of military maneuvers. Alter deployments and change original plans on the fly, so no one can discern your true intentions. Shift positions frequently and take deliberate detours to obscure your objectives. Issue orders to subordinates like removing a ladder after ascending—forcing them to advance without retreat. Lead troops deep into enemy territory like an arrow shot from a crossbow, seizing the perfect moment to strike, burning boats and smashing pots to press forward without hesitation. Command soldiers as if herding sheep—driving them here and there, never revealing the final destination. Gather the entire army and place them in a perilous position, compelling them to fight to the death. This is the duty of a commander. The flexible application of various terrains, the advantages and disadvantages of offense and defense, and the psychological patterns of soldiers in different environments—these are all matters a general must carefully study and examine.
When operating within enemy territory, the deeper you penetrate, the more unified the army becomes; the harder it is to advance, the more easily morale scatters. Ground entered deep in enemy territory is called desperate ground; ground accessible from all directions is called intersecting ground; ground deep behind enemy lines is called heavy ground; ground entered only a short distance is called light ground; ground with difficult terrain ahead and obstacles behind is called encircled ground; ground with no way out is called death ground. Therefore, in battle, on dispersive ground, unify the army's will; on light ground, keep the camps tightly connected; when contending for ground, ensure follow-up troops advance swiftly; when passing through open ground, guard carefully; on intersecting ground, strengthen alliances with neighboring states; on heavy ground, secure supplies; on treacherous ground, pass through quickly; when trapped in encircled ground, block the gaps; on death ground, show the determination to fight to the death. Thus, the pattern of soldiers' psychology is: when surrounded, they unite to resist; when there is no alternative, they fight desperately; when plunged into deep danger, they become highly obedient to command.
Therefore, without understanding the strategic intentions of the feudal lords of various states, one cannot form alliances with them. Without familiarity with terrain such as mountains, forests, obstacles, and marshes, one cannot march and engage in battle. Without using local guides, one cannot gain the advantages of the terrain. If any of these conditions are not met, an army cannot be considered one that seeks to dominate and rule. A truly powerful army, when attacking a large state, moves with such swiftness that the enemy cannot mobilize its people or assemble its forces in time. When it exerts military pressure on the enemy, it prevents their allies from coordinating and responding. Therefore, there is no need to compete in forming alliances with all the lords of the world, nor to cultivate influence within their states. As long as one can execute their strategic intent and direct military force against the enemy, they can capture the enemy's cities and destroy their capital.
Bestow extraordinary rewards and issue unconventional commands, so that directing the entire army becomes as easy as commanding a single person. When assigning tasks to subordinates, do not reveal your intentions; only inform them of favorable conditions, without pointing out the disadvantages. Place soldiers in perilous situations to turn danger into safety; thrust them into deadly ground to bring them back from the brink of death. Only when soldiers are pushed into desperate straits can defeat be transformed into victory.
Therefore, the key to commanding operations lies in discerning the enemy's intentions, deceiving them, then concentrating elite forces to strike their vital points. In this way, even after a thousand-mile march, you can slay the enemy's general. This is what is meant by achieving great things through strategic acumen.
Therefore, when determining war strategy, seal the passes, invalidate travel permits, and cease all diplomatic contact with the enemy state. The court must deliberate repeatedly on war plans. Once the enemy reveals a vulnerability, strike swiftly to exploit it. First seize the enemy's most critical strategic positions, but do not rashly commit to pitched battles. Remain flexible—adjust your battle plans and actions according to the enemy's situation. Thus, before battle, be still as a maiden, revealing nothing, luring the enemy into lowering their guard and opening their gates wide; once battle begins, move like an escaping rabbit—swift and sudden—catching the enemy off balance, leaving them no chance to resist.
Commentary
There are many methods of warfare, and understanding the terrain of battle is crucial. Sun Wu summarized six types of battlefields and proposed targeted strategies for each. He also discussed the reasons for adaptability, and more importantly, analyzed the psychology of both our own troops and the enemy. This is the earliest and most outstanding work on military psychology.
Example Interpretation
Geng Yan struck once and gained two victories, while Rommel was defeated in North Africa.
This chapter primarily discusses nine types of combat environments, classified by the "host-guest" dynamic and the degree of penetration into enemy territory, along with their corresponding tactical requirements. Different levels of understanding and responses to these environments lead to vastly different outcomes.
In the fifth year of the Jianwu era under Emperor Guangwu of Han, Eastern Han general Geng Yan led his troops into Shandong. He observed that Xi'an (present-day Zibo, Shandong) had a small but well-fortified city, while Linzi was large but easy to attack. So he spread word that he would attack Xi'an in five days. Upon hearing this, Xi'an's defender Zhang Lan deployed troops to guard the city day and night. However, five days later, Geng Yan marched on Linzi instead. The defender of Linzi, Zhang Bu, was caught completely off guard, and chaos erupted as the army approached. Geng Yan captured Linzi in just half a day, then immediately turned his forces toward Xi'an. Frightened, Zhang Lan fled overnight, and Geng Yan took both cities with a single battle. His subordinates were baffled. Geng Yan explained: "If we had attacked Xi'an first, they were prepared, and we would have been stuck in a prolonged siege—dangerous for us deep in enemy territory. But striking Linzi, which was unprepared, was far easier. Once Linzi fell, the enemy in Xi'an dared not fight us and had no choice but to flee."
Geng Yan was truly skilled in the art of war. He employed proper methods in enemy territory, applied sound tactics, and even used psychological warfare. Thus, he could "strike once and gain twice." In contrast, though also fighting deep in hostile lands, the fate of Germany's Rommel was entirely different.
In early August 1942, German commander Rommel in North Africa planned an offensive against British forces. He chose to attack at the southern end of the Alamein line, believing British defenses there were weak and the assault would succeed. By mid-August, Rommel began redeploying his troops, secretly moving them south. British General Montgomery analyzed the enemy's situation and terrain, concluding that Rommel was largely unfamiliar with the area around Ragil Ridge. In certain parts of the Ragil region, the sand was deep and shifting, which would certainly hinder German armored operations. Montgomery thus decided to lure Rommel into the Ragil area and destroy him there. To bait Rommel, the British fabricated intelligence and deliberately drew a map of Ragil, marking it as hard ground favorable for German armor, and cleverly ensured this map reached Rommel. Upon receiving it, Rommel was delighted, convinced his original plan would succeed, and never doubted the map's source or reliability.
On the early morning of September 1, Rommel launched an attack on the Rajil area as planned. Montgomery, fully prepared, lured the enemy step by step into the trap. Soon, the German forces entered a quicksand zone, where dozens of tanks, armored vehicles, and trucks struggled and tilted in the shifting sands marked as hard ground on the British decoy map. As soldiers dismounted to push the vehicles, they were immediately subjected to repeated bombing and strafing by several squadrons of British fighter planes. Soon, the desert was littered with burning German vehicles. On September 4, Rommel had no choice but to order a retreat from the area, marking a complete defeat for the so-called "Desert Fox."
"Fighting on unfavorable terrain" is a major taboo in military strategy. Choosing advantageous terrain for decisive battle allows one to seize the initiative in war; conversely, unfavorable terrain increases the difficulty of combat. When terrain is disadvantageous, either avoid battle or lure the enemy out, stripping them of their geographical advantage. Rommel suffered a crushing defeat precisely because he overlooked the importance of terrain.