Original Text
Sun Tzu said: When deploying troops and observing the enemy across different terrains, pay attention to the following: When crossing mountainous terrain, choose valleys with water and grass, camp in a high and sunny position, and never attack an enemy who holds the high ground. This is the principle of deploying troops in mountains. After crossing a river, camp at a distance from the water; if the enemy wades across, do not meet them in the water but strike when half have crossed, which is more advantageous. If you must engage in battle, do not array your forces near the water; when camping in river regions, also choose high, sunny ground and do not face the current. This is the principle of deploying troops in river regions. When crossing salt marshes and alkaline wastelands, move quickly without lingering; if you encounter the enemy, stay close to water and grass with your back to the woods. This is the principle of deploying troops in salt marshes. On plains, occupy open ground with your flanks relying on high ground, low in front and high behind. This is the principle of deploying troops on plains. Mastering these four principles of troop deployment and applying them successfully is how the Yellow Emperor defeated the other four emperors.
In general, when encamping, always prefer dry, high ground and avoid damp, low areas. Value sunny places and shun dark ones. Stay close to areas with abundant water and grass, where supplies are ample, and set up camp on high, solid ground so that soldiers remain free from illness—this ensures victory. When marching through hilly terrain or along embankments, you must occupy the sunny side, and let your main flank also face the sun. These measures benefit military operations because they fully leverage the advantages of the terrain. If rain falls upstream and flash floods occur, do not wade across the river; wait until the water level stabilizes before moving. Whenever you encounter or pass through terrain such as "sheer ravines," "natural wells," "natural prisons," "natural nets," "natural traps," or "natural fissures," you must quickly leave and never linger. Keep our forces far from such terrain while drawing the enemy toward it; let our forces face these features while the enemy has them at their back. Near the camp, if there are mountain passes, water obstacles, pits, marshes, dense reeds, or thick forests, you must search them thoroughly and repeatedly—these are places where the enemy may set ambushes or hide spies.
When the enemy is near and remains calm, it is because they hold advantageous terrain. When the enemy comes from afar to provoke battle, they seek to lure you forward. When the enemy does not seize key terrain but camps on flat ground, there is surely some advantage for them there. Many trees swaying indicate the enemy is cutting wood to clear a path for a concealed approach. Many obstacles in the grass are decoys set by the enemy. Birds taking flight in alarm signal ambushes below. Beasts fleeing in terror mean the enemy is launching a sudden large-scale attack. Dust rising high and straight shows the enemy's chariots are advancing in force. Dust low and wide indicates the enemy's infantry is on the move. Dust scattered and rising means the enemy is dragging brush to create a false trail. Dust sparse and rising intermittently means the enemy is setting up camp. When the enemy's envoy speaks humbly but intensifies war preparations, they are about to attack. When they speak harshly and assume an offensive posture, they are preparing to retreat. When light chariots deploy first on both flanks, they are forming battle lines. When the enemy seeks peace without suffering a setback, they have a hidden scheme. When they rush to deploy in battle formation, they intend to engage you in a decisive battle on a set date. When they seem to advance but not, and retreat but not, they are trying to lure you into a trap. Soldiers leaning on their weapons are a sign of hunger. Water carriers drinking before their troops are a sign of thirst. Seeing an advantage but not seizing it is a sign of exhaustion. Birds gathering over a camp mean it is empty. Nighttime cries in the enemy camp are a sign of panic. Chaos and disorder in the camp mean the commander lacks authority. Flags moving erratically indicate lax discipline and disorderly ranks. An irritable commander signals exhausted troops. Killing horses for meat means the enemy is short on food. Cooking pots hung up unused and soldiers not returning to their tents mean they are desperate and ready to fight to the death. A commander speaking softly and submissively to his men shows he has lost their loyalty. Frequent rewards to troops indicate the enemy is in dire straits. Frequent punishments show the enemy is at wit's end. A commander who is first harsh and then fearful of his men is the least wise. An envoy sent with gifts and kind words means the enemy wants a truce. When the enemy comes in anger but delays battle and does not withdraw, you must carefully observe their intentions.
The key to warfare is not simply having more troops. As long as you do not underestimate the enemy or advance recklessly, can concentrate your forces, discern the enemy's situation, and earn the trust and support of your men, that is enough. Those who lack deep strategy yet are arrogant and underestimate the enemy will surely be captured by them.
If soldiers have not yet become attached and loyal, punishing them will make them resentful, and resentment makes them hard to command. If soldiers have already become attached and loyal, but military discipline is not enforced, they cannot be led into battle either. Therefore, use benevolent policies to unite their hearts and military law to align their actions—this will surely earn their respect and support. When orders are strictly enforced in peacetime, soldiers develop the habit of obedience; if orders are not enforced in peacetime, soldiers develop the habit of disobedience. When orders are enforced in peacetime, it shows that the commander and soldiers are in harmony and trust each other.
Commentary
Marching is a key strategy in warfare. Ancient battles emphasized the freedom to advance and retreat, while modern warfare introduced mobile combat. Thus, marching, troop deployment, and assessing enemy situations are three essential principles of military operations.
Example Interpretation
King Wei of Qi Rewards and Punishes with Clarity
In 615 BC, the Qin army attacked the Jin state but failed to secure victory after prolonged fighting, so they decided to withdraw. Before this, Qin sent a silver-tongued envoy to the Jin camp. The envoy spoke with fierce words and challenged the Jin army to a decisive battle in front of their camp two days later. The Jin military strategist saw through Qin's ruse and advised launching a night attack to intercept the Qin forces. However, the Jin commander dismissed this idea. That night, scouts were sent to investigate, only to discover that the entire Qin army had already retreated safely.
Examples of missed opportunities due to a commander's lack of insight are everywhere. Clear perception and a proper system of rewards and punishments are especially crucial for team management and enhancing military effectiveness.
In the early Warring States period, when King Wei of Qi first ascended the throne, he entrusted state affairs to his high ministers. For nine years, the kingdom was poorly governed, and neighboring states repeatedly invaded Qi. Then King Wei took power into his own hands and personally assessed his ministers.
He summoned the Grand Master of Jimo and said to him: "Ever since you took office in Jimo, slanderous words about you have come to me daily. Yet I sent someone to inspect Jimo and saw that the fields were opened up, the people were prosperous, officials were at ease with little to do, and the eastern part of the state was thus very stable. It is clear that you never bribed those around me to seek their help on your behalf!" So King Wei of Qi granted him the tax revenue of ten thousand households.
King Wei of Qi then summoned the governor of A Yi and said to him: "In the past, when the state of Zhao attacked Yi, you did not send reinforcements. When the state of Wei captured Xueling, you were completely unaware. It is clear that you used large sums of money to bribe those around me, asking them to speak well of you." King Wei of Qi ordered the governor of A Yi to be executed, and also severely punished those close to him who had accepted bribes and spoken favorably on behalf of the governor of A Yi.
King Wei of Qi rewarded and punished his officials with clear standards, commending the capable and penalizing the incompetent, which brought great order to the state of Qi. Later, he led his army to defeat invading states such as Zhao, Wei, and Wei, reigning as king for thirty-six years, making Qi more prosperous and powerful than its neighboring states.