The Art of War

Sunzi said: Warfare is a great affair of state, the ground of life and death, the way to survival or destruction. It must be examined. Therefore, assess it by the five fundamentals, compare it by the seven calculations, and thereby seek out its true condition. The first is the Way; the second, Heaven; the third, ground; the fourth, the commander; the fifth, method.

The Way causes the people to share the will of their ruler, so that they may die with him, may live with him, and fear no danger. Heaven comprises darkness and light, cold and heat, and the ordering of the seasons. Ground comprises high and low, far and near, difficult and easy, broad and narrow, and places of death and life. The commander comprises wisdom, trustworthiness, benevolence, courage, and sternness. Method comprises the organization of units, the regulation of officers, and the control of supplies. Every commander has heard of these five, but he who understands them is victorious, and he who does not is not victorious. Therefore, compare them by the seven calculations and seek out their true condition, asking: Which ruler possesses the Way? Which commander has ability? Who has gained the advantages of Heaven and ground? On which side are laws and orders carried out? Whose forces are stronger? Whose officers and soldiers are better trained? Whose rewards and punishments are clearer? From these I know victory and defeat.

If a commander will heed my calculations, employ him, and he will surely be victorious; retain him. If a commander will not heed my calculations, employ him, and he will surely be defeated; dismiss him. Once the advantageous calculations have been heeded, create strategic power to assist them from without. Strategic power is the control of circumstances in accordance with advantage. Warfare is the Way of deception. Therefore, when capable, show yourself incapable; when employing your forces, show yourself inactive; when near, show yourself far away; when far away, show yourself near. Lure the enemy with profit; take him when he is in disorder. When he is substantial, prepare against him; when he is strong, avoid him. When he is angry, provoke him; when he is humble, make him arrogant. When he is rested, weary him; when his forces are united, divide them. Attack where he is unprepared; emerge where he does not expect you. These are the military strategist’s means of victory; they cannot be transmitted in advance.

Before battle, he whose calculations in the ancestral temple foretell victory has made many calculations; before battle, he whose calculations in the ancestral temple do not foretell victory has made few calculations. Many calculations bring victory; few calculations do not bring victory. How much less can there be victory without calculation at all? By observing the matter in this way, victory and defeat become apparent.

Sunzi said: In general, the method of employing troops is this: when there are a thousand swift chariots, a thousand leather-covered chariots, a hundred thousand armored soldiers, and provisions transported a thousand miles, then expenditures at home and in the field, allowances for envoys and guests, materials such as glue and lacquer, and the maintenance of chariots and armor will cost a thousand pieces of gold each day. Only then can an army of one hundred thousand be raised. When such an army is employed in battle, what matters is swift victory. If war is prolonged, weapons grow dull and ardor is blunted; if cities are attacked, strength is exhausted; if the army is kept long in the field, the state’s resources prove insufficient. Once weapons are dull, ardor blunted, strength exhausted, and wealth depleted, the feudal lords will rise to exploit the weakness. Then, though there may be wise men, none can make good what follows. Thus, in war we have heard of clumsy haste, but we have never seen skillful delay. Never has there been a prolonged war that benefited a state. Therefore, one who does not fully understand the harm inherent in employing troops cannot fully understand the advantages of employing them.

One skilled in employing troops does not levy soldiers twice or transport provisions three times. He draws equipment from his own state but takes provisions from the enemy; thus the army can have food enough.

What impoverishes a state through its army is transporting supplies over great distances. When supplies are transported far, the common people are impoverished. Near an army, goods are sold at high prices; when prices are high, the people’s wealth is exhausted. When their wealth is exhausted, they are pressed by levies and labor service. With strength spent and wealth depleted, the households of the heartland are left empty. Of the common people’s resources, seven-tenths are lost; of the public treasury’s resources, six-tenths are lost through broken chariots, worn-out horses, armor and helmets, arrows and crossbows, halberds and shields, mantlets and large shields, draft oxen and heavy wagons.

Therefore, a wise commander makes it his business to feed upon the enemy. One measure of the enemy’s grain is equal to twenty of ours; one load of his fodder is equal to twenty loads of ours.

Thus, what makes men kill the enemy is anger; what makes them seize advantage from the enemy is material reward. Therefore, in chariot fighting, when ten or more chariots are captured, reward the first man to take one, replace the enemy’s banners and flags, mingle the captured chariots with your own and use them, and treat captured soldiers well and maintain them. This is called defeating the enemy and growing stronger.

Thus, in war, prize victory, not protraction. Therefore, a commander who understands warfare is the arbiter of the people’s fate and the master of the state’s security or peril.

Sunzi said: In general, the method of employing troops is this: preserving an enemy state intact is best; destroying the state is second best. Preserving an enemy army intact is best; destroying the army is second best. Preserving an enemy brigade intact is best; destroying the brigade is second best. Preserving an enemy battalion intact is best; destroying the battalion is second best. Preserving an enemy squad intact is best; destroying the squad is second best. Therefore, to win a hundred victories in a hundred battles is not the highest excellence; to subdue the enemy’s army without battle is the highest excellence.

Thus, the highest form of warfare is to attack plans; the next is to attack alliances; the next is to attack armies; the lowest is to attack fortified cities. The method of attacking a city is undertaken only when unavoidable. Preparing great shields and armored assault wagons and making ready the equipment and weapons require three months; piling up earthen ramps against the walls requires another three months. If the commander cannot master his anger and sends his men swarming like ants against the walls, one-third of the officers and soldiers will be killed without the city being taken. Such is the calamity of siege warfare.

Therefore, one skilled in employing troops subdues the enemy’s army without battle, takes the enemy’s cities without assault, and destroys the enemy’s state without prolonged operations. He must contend for all under Heaven with preservation as his aim. Thus his troops are not worn down, and his gains can be kept complete. This is the method of attacking by strategy.

Thus, the method of employing troops is this: if ten times the enemy’s strength, surround him; if five times his strength, attack him; if twice his strength, divide him; if equal to him, be able to fight him; if fewer, be able to defend against him; if inferior, be able to avoid him. Therefore, the obstinacy of a small force makes it the captive of a larger force.

The commander is the state’s supporting pillar. If the support is complete, the state will surely be strong; if the support is defective, the state will surely be weak.

There are three ways in which a ruler brings trouble upon his army. Not knowing that the army must not advance, he orders it to advance; not knowing that the army must not retreat, he orders it to retreat. This is called fettering the army. Not understanding the affairs of the three armies, he shares in their administration; then the officers and soldiers become confused. Not understanding the tactical authority of the three armies, he shares in their command; then the officers and soldiers become doubtful. Once the three armies are both confused and doubtful, trouble from the feudal lords will arrive. This is called throwing the army into disorder and leading victory away.

Thus there are five ways to know victory. He who knows when one can fight and when one cannot will be victorious. He who understands how to employ many and few will be victorious. He whose superiors and subordinates share the same desire will be victorious. He who is prepared and awaits the unprepared will be victorious. He whose commander is capable and is not constrained by his ruler will be victorious. These five are the Way to know victory.

Therefore it is said: Know the enemy and know yourself, and in a hundred battles you will never be imperiled. Know yourself but not the enemy, and for every victory you will suffer a defeat. Know neither the enemy nor yourself, and in every battle you will surely be imperiled.

Sunzi said: Those of old who were skilled in battle first made themselves invincible, then awaited the moment when the enemy could be defeated. Invincibility lies with oneself; vulnerability to defeat lies with the enemy. Therefore, one skilled in battle can make himself invincible, but cannot make the enemy necessarily vulnerable to defeat. Thus it is said: Victory can be known, but it cannot be forced.

Invincibility lies in defense; vulnerability to defeat lies in attack. One defends when strength is insufficient and attacks when strength is abundant. One skilled in defense hides beneath the deepest layers of the earth; one skilled in attack moves above the highest reaches of Heaven. Thus he can preserve himself and gain complete victory.

To foresee a victory no better than the common multitude can foresee it is not the highest excellence. To win in battle and have all under Heaven acclaim your skill is not the highest excellence. Thus, lifting an autumn hair does not signify great strength; seeing the sun and moon does not signify keen sight; hearing thunder does not signify acute hearing.

Those whom the ancients called skilled in battle gained victory over those who were easy to defeat. Thus, the victories of one skilled in battle bring neither a reputation for wisdom nor merit for courage. His victories in battle admit no error. They admit no error because whatever measures he takes are certain to prevail: he conquers an enemy already defeated. Therefore, one skilled in battle establishes himself on ground where he cannot be defeated and does not miss the enemy’s moment of defeat. Thus, a victorious army first secures victory and then seeks battle; a defeated army first fights and then seeks victory. One skilled in employing troops cultivates the Way and preserves method; therefore, he can govern victory and defeat.

According to the methods of war, the first factor is measurement; the second, estimation of capacity; the third, calculation; the fourth, comparison; the fifth, victory. Ground gives rise to measurement; measurement gives rise to estimation of capacity; estimation of capacity gives rise to calculation; calculation gives rise to comparison; comparison gives rise to victory. Thus, a victorious army is like weighing a hundredweight against a grain, while a defeated army is like weighing a grain against a hundredweight. When the victor sends his people into battle, it is like releasing pent-up waters into a ravine a thousand fathoms deep. This is disposition.

Sunzi said: In general, commanding many is like commanding few; it is a matter of divisions and numbers. Fighting with many is like fighting with few; it is a matter of formations and signals. That the multitude of the three armies can be made to withstand the enemy without defeat is a matter of extraordinary and regular forces. That the army’s blow may be like a whetstone hurled against an egg is a matter of emptiness and substance.

In every battle, engage with the regular and gain victory with the extraordinary. Therefore, one skilled in bringing forth the extraordinary is inexhaustible as Heaven and earth, unending as rivers and seas. Ending and beginning again—such are the sun and moon. Dying and being born again—such are the four seasons. There are no more than five notes, yet the transformations of the five notes can never all be heard. There are no more than five colors, yet the transformations of the five colors can never all be seen. There are no more than five flavors, yet the transformations of the five flavors can never all be tasted. In battle, strategic configurations do not exceed the extraordinary and the regular, yet the transformations of the extraordinary and the regular can never be exhausted. The extraordinary and the regular give rise to each other like a ring without beginning or end. Who can exhaust them?

The rush of pent-up water that carries stones along is strategic power; the swift strike of a bird of prey that shatters its victim is timing. Therefore, one skilled in battle makes his strategic power steep and his timing brief. His strategic power is like a drawn crossbow; his timing is like releasing the trigger.

Amid tumult and uproar, the battle seems chaotic, yet cannot be thrown into disorder. Amid confusion and obscurity, the formation seems circular, yet cannot be defeated. Apparent disorder is born from order; apparent cowardice is born from courage; apparent weakness is born from strength. Order and disorder are a matter of organization; courage and cowardice, a matter of strategic power; strength and weakness, a matter of disposition.

Therefore, one skilled at moving the enemy presents a disposition the enemy must follow; he offers something the enemy must take. He moves the enemy with profit and awaits him with troops.

Therefore, one skilled in battle seeks victory from strategic power and does not demand it from individual men. Thus he can select men and entrust them to strategic power. One who relies on strategic power sends men into battle as though rolling logs and stones. The nature of logs and stones is to remain still on level ground and move on steep ground; if square, they stop; if round, they roll. Thus, the strategic power of one skilled at sending men into battle is like rolling round stones down a mountain a thousand fathoms high. This is strategic power.

Sunzi said: In general, he who occupies the battleground first and awaits the enemy is at ease; he who arrives later and hastens into battle is weary. Therefore, one skilled in battle compels others and is not compelled by them.

What can make the enemy come of his own accord is profit; what can prevent the enemy from coming is harm. Therefore, if the enemy is rested, one can weary him; if well fed, one can starve him; if settled, one can move him. Emerge where he must hasten; hasten where he does not expect you.

To march a thousand miles without weariness, travel through ground where there is no enemy. To attack and be certain of taking the objective, attack what the enemy does not defend. To defend and be certain of holding firm, defend what the enemy does not attack. Therefore, against one skilled in attack, the enemy does not know where to defend; against one skilled in defense, the enemy does not know where to attack. Subtle, subtle! He reaches the point of having no form. Divine, divine! He reaches the point of making no sound. Thus he can become the arbiter of the enemy’s fate.

He advances irresistibly by striking the enemy’s emptiness; he retreats beyond pursuit by moving too swiftly to be overtaken. Thus, when I desire battle, though the enemy has high ramparts and deep moats, he cannot avoid fighting me, because I attack what he must rescue. When I do not desire battle, though I merely draw a line upon the ground and defend it, the enemy cannot fight me, because I divert him from his intended course.

Therefore, if I reveal the enemy’s disposition while remaining formless myself, I can concentrate while he must divide. I concentrate into one; he divides into ten. Thus I use ten to attack his one, so that I am many and the enemy is few. If I can use many to strike few, those with whom I do battle will be severely constrained. The place where I shall fight must remain unknown. If it is unknown, the enemy must prepare in many places; if he prepares in many places, those with whom I fight will be few. Thus, if he prepares the front, his rear will be weak; if he prepares the rear, his front will be weak; if he prepares the left, his right will be weak; if he prepares the right, his left will be weak. If he prepares everywhere, he will be weak everywhere. He who is few prepares against others; he who is many makes others prepare against him.

Therefore, if one knows the place and the day of battle, one can march a thousand miles and join battle. If one knows neither the place nor the day of battle, the left cannot rescue the right, the right cannot rescue the left, the front cannot rescue the rear, and the rear cannot rescue the front—how much less when the distant are tens of miles away and even the near are several miles apart? By my reckoning, though the troops of Yue are many, what help can that be toward victory? Thus it is said: Victory can be seized. Though the enemy is numerous, he can be made unable to fight.

Therefore, calculate against the enemy to learn the success or failure of his plans; provoke him to learn the principles of his movement and stillness; reveal his disposition to learn the ground of death and life; probe him to learn where he has abundance and where insufficiency. Thus, the ultimate disposition of troops is to reach formlessness. When you are formless, the deepest spy cannot discern you, nor can the wise devise plans against you. In accordance with the enemy’s disposition, one places victory before the multitude, but the multitude cannot understand it. Everyone knows the disposition by which I gained victory, but no one knows the disposition by which I controlled victory. Therefore, a victorious strategy is not repeated but responds to changing dispositions without end.

The disposition of troops resembles water. In its course, water avoids the high and hastens to the low; in gaining victory, an army avoids the substantial and strikes the empty. Water shapes its course according to the ground; an army shapes its victory according to the enemy. Therefore, an army has no fixed strategic configuration and no constant form. One who can transform himself in accordance with the enemy and thereby gain victory is called divine. Thus, among the five phases none is always victorious; among the four seasons none forever holds its place. The days are long and short; the moon wanes and waxes.

Sunzi said: In general, the method of employing troops is this: the commander receives his charge from the ruler, assembles the army, and gathers the multitude. From the moment the opposing forces confront one another and encamp, nothing is more difficult than contending for advantage. The difficulty in contending for advantage lies in making the circuitous direct and turning adversity into gain. Therefore, take a circuitous route while luring the enemy with profit; set out after him yet arrive before him. This is to understand the calculation of the circuitous and the direct.

Thus, contending for advantage brings profit, and contending for advantage brings peril. If the entire army is moved to contend for advantage, it will not arrive in time; if the army is left behind to contend for advantage, the baggage and heavy equipment will be abandoned. Therefore, if men roll up their armor and hasten onward, neither resting by day nor halting by night, doubling their marches and joining stages together, and march a hundred miles to contend for advantage, the commanders of all three armies will be captured. The vigorous will arrive first, the weary will fall behind, and only one-tenth will arrive. If they march fifty miles to contend for advantage, the commander of the vanguard will be brought down, and only half will arrive. If they march thirty miles to contend for advantage, two-thirds will arrive. Thus, an army without baggage and heavy equipment perishes; without provisions it perishes; without stores it perishes. Therefore, one who does not know the plans of the feudal lords cannot enter alliances beforehand. One who does not know the configuration of mountains and forests, dangerous defiles and obstacles, marshes and swamps, cannot move an army. One who does not employ local guides cannot gain the advantages of the ground.

Therefore, warfare is founded upon deception, moves according to advantage, and transforms through division and concentration. Thus, let your swiftness be like the wind, your measured advance like a forest; in invasion and plunder be like fire, in stillness be like a mountain; be inscrutable as darkness, and when you move, strike like thunder. When plundering the countryside, divide your forces; when expanding your territory, divide the gains. Weigh the balance and then move. He who first understands the calculation of the circuitous and the direct will be victorious. This is the method of contending for advantage.

The Book of Military Administration says: “Because spoken words cannot be heard one by another, gongs and drums are made; because men cannot see one another, banners and flags are made.” Gongs, drums, banners, and flags are the means of unifying the people’s ears and eyes. Once the people are unified, the courageous cannot advance alone, nor can the cowardly retreat alone. This is the method of employing a multitude. Therefore, in night fighting use many gongs and drums; in day fighting use many banners and flags. These are the means of directing the people’s ears and eyes.

The spirit of the three armies can be taken away; the commanding general’s mind can be taken away. Thus, in the morning the enemy’s spirit is keen; by midday his spirit is indolent; by evening his spirit longs to return. Therefore, one skilled in employing troops avoids the enemy’s keen spirit and strikes when his spirit is indolent or bent on returning. This is mastery of spirit. Await disorder in good order; await clamor in tranquility. This is mastery of mind. Await those from afar while near; await the weary while rested; await the hungry while well fed. This is mastery of strength. Do not intercept banners in perfect order; do not attack formations in imposing array. This is mastery of adaptation.

Thus, the method of employing troops is this: do not advance uphill against an enemy on high ground; do not oppose an enemy with a hill at his back; do not pursue a feigned retreat; do not attack keen troops; do not swallow baited troops; do not obstruct an army returning home; when surrounding an army, leave an opening; do not press a desperate enemy. This is the method of employing troops.

Sunzi said: In general, the method of employing troops is this: the commander receives his charge from the ruler, assembles the army, and gathers the multitude. Do not encamp on broken ground. On intersecting ground, join alliances. Do not linger on isolated ground. On encircled ground, make plans. On death ground, fight. There are roads that must not be followed, armies that must not be attacked, cities that must not be assaulted, ground that must not be contested, and commands from the ruler that must not be obeyed. Therefore, a commander who understands the advantages of the nine adaptations knows how to employ troops. A commander who does not understand the advantages of the nine adaptations, though he knows the configuration of the ground, cannot gain its advantages. One who commands an army without knowing the art of the nine adaptations, though he knows the advantages of the ground, cannot obtain the full use of his men.

Therefore, the wise man’s deliberations always mingle advantage and harm. By mingling advantage with harm, his undertakings can be trusted to succeed; by mingling harm with advantage, his troubles can be resolved. Thus, subdue the feudal lords with harm, keep the feudal lords occupied with burdens, and make the feudal lords hasten with profit.

Therefore, the method of employing troops is not to rely on the enemy’s failure to come, but on our readiness to receive him; not to rely on his failure to attack, but on our possession of a position that cannot be attacked.

Thus, a commander has five dangers: if determined to die, he can be killed; if determined to live, he can be captured; if quick to anger, he can be provoked; if scrupulous about honor, he can be humiliated; if he loves the people, he can be troubled. These five are faults in a commander and calamities in employing troops. The destruction of an army and the death of its commander inevitably arise from these five dangers. They must be examined.

Sunzi said: In general, when stationing an army and observing the enemy, cross mountains by keeping near valleys; face the sun and occupy high ground; when fighting on elevated ground, do not climb to attack. This is how to station an army in mountains. After crossing a river, you must move far from the water. When an invading enemy crosses a river to approach, do not meet him in the water. Let half his force cross and then strike him; this is advantageous. If you desire battle, do not meet an invader close beside the water. Face the sun and occupy high ground; do not face the current. This is how to station an army near water. Cross salt marshes quickly; do not linger. If you encounter an enemy within a salt marsh, you must keep near water and grass, with masses of trees at your back. This is how to station an army in salt marshes. On level ground, occupy easy terrain with high ground to your right and rear, deadly ground before you and secure ground behind you. This is how to station an army on level ground. These four advantageous ways of stationing an army enabled the Yellow Emperor to conquer the Four Emperors.

In general, an army prefers high ground and detests low ground, esteems sunlight and disdains shade, nourishes life and occupies substantial ground. Then the army will be free of a hundred illnesses. This is called certain victory. Among hills, embankments, and dikes, always occupy the sunny side and keep them to your right and rear. This is the advantage of warfare and the assistance of the ground. When rain has fallen upstream and foam comes down upon the water, if you wish to cross, wait until the waters subside.

Wherever the ground contains sheer ravines, Heaven’s Wells, Heaven’s Prisons, Heaven’s Nets, Heaven’s Pits, or Heaven’s Fissures, you must leave quickly and not approach them. Keep them far from us and near the enemy; face them while making the enemy place them at his back. If near the army there are dangerous defiles and obstacles, ponds and hollows, reeds and rushes, forests, or dense undergrowth, these must be searched thoroughly and carefully, for these are places where ambushes and spies conceal themselves.

When the enemy is near yet quiet, he relies on the strength of his ground. When he is far away yet challenges you to battle, he wants you to advance. When the place he occupies is easy of access, he is offering an advantage. When masses of trees move, he is coming. When many screens appear among the grass, he seeks to arouse suspicion. When birds rise in flight, there is an ambush. When wild beasts are startled, a surprise attack is coming. When dust rises high and sharp, chariots are approaching. When it hangs low and spreads broadly, infantry is approaching. When it is scattered in separate streaks, men are gathering firewood. When small clouds of dust move to and fro, the army is making camp. Humble words accompanied by increased preparations mean he will advance. Forceful words accompanied by an impetuous approach mean he will retreat. When light chariots emerge first and take position on the wings, he is forming for battle. When he seeks peace without a sworn covenant, he is plotting. When men rush about and troops are arrayed, the appointed moment has come. When some advance and others retreat, he is enticing you. When men lean on their weapons while standing, they are hungry. When water carriers drink before bearing water back, they are thirsty. When they see an advantage but do not advance, they are weary. When birds gather, the place is empty. When men call out at night, they are afraid. When the army is disturbed, the commander lacks authority. When banners and flags move about, there is disorder. When officers are angry, the men are exhausted. When they feed grain to horses, slaughter livestock for food, do not hang up their cooking pots, and do not return to their shelters, they are desperate enemies. When men gather in little groups and speak softly and at length, the commander has lost the multitude. Frequent rewards indicate distress; frequent punishments indicate exhaustion. He who is first brutal and afterward fears his men has reached the extreme of incompetence. Envoys who come with conciliatory messages seek a respite. If the troops angrily confront each other for a long time without joining battle and without withdrawing, the situation must be examined with the utmost care.

Thus, in war, mere superiority in numbers is not what is prized. It is enough not to advance recklessly, but to concentrate strength, assess the enemy, and win the support of your men. He who lacks forethought and treats the enemy lightly will surely be captured by others.

If soldiers are punished before they have grown attached to you, they will not submit; if they do not submit, they will be difficult to employ. If soldiers have already grown attached to you but punishments are not enforced, they cannot be employed. Therefore, command them through civil means and unify them through martial discipline. This is called certain victory. If orders have consistently been enforced when instructing the people, the people will submit. If orders have not consistently been enforced when instructing the people, the people will not submit. Consistent enforcement of orders means that the commander and the multitude are in accord.

Sunzi said: In general, configurations of ground include accessible ground, entangling ground, temporizing ground, constricted ground, precipitous ground, and distant ground. Ground across which we can go and the enemy can come is called accessible. On accessible ground, first occupy high, sunny positions and secure your supply routes; then battle will be advantageous. Ground across which one can go but from which it is difficult to return is called entangling. On entangling ground, if the enemy is unprepared, go forth and defeat him. If the enemy is prepared and you go forth without defeating him, it will be difficult to return, and this is disadvantageous. Ground upon which it is disadvantageous for us to go forth and disadvantageous for the enemy to go forth is called temporizing. On temporizing ground, though the enemy offers us an advantage, we must not go forth. Draw away and depart, causing the enemy to come halfway out, then strike him; this is advantageous. On constricted ground, if we occupy it first, we must fill it completely and await the enemy. If the enemy occupies it first and has filled it completely, do not follow him; if he has not filled it completely, follow him. On precipitous ground, if we occupy it first, we must occupy high, sunny positions and await the enemy. If the enemy occupies it first, draw away and depart; do not follow him. On distant ground, if forces are evenly matched, it is difficult to provoke battle, and fighting is disadvantageous. These six are the Ways of ground. They are the commander’s highest responsibility and must be examined.

Thus, an army may flee, become insubordinate, collapse, crumble, fall into disorder, or be routed. These six are not calamities from Heaven but faults of the commander. When forces are evenly matched and one attacks ten, the result is flight. When soldiers are strong and officers weak, the result is insubordination. When officers are strong and soldiers weak, the result is collapse. When senior officers are angry and insubordinate, and on meeting the enemy act from resentment and fight on their own because the commander does not know their abilities, the result is crumbling. When the commander is weak and not stern, his instruction and direction are unclear, officers and soldiers lack fixed duties, and the battle lines are drawn up every which way, the result is disorder. When the commander cannot assess the enemy, pits a small force against a large one, attacks strength with weakness, and has no picked vanguard among his troops, the result is rout. These six are Ways to defeat. They are the commander’s highest responsibility and must be examined.

The configuration of the ground is an aid to the army. Assessing the enemy to control victory, and calculating dangers, constrictions, distances, and proximities, constitute the Way of a superior commander. He who knows these things and employs them in battle will surely be victorious; he who does not know them and employs troops in battle will surely be defeated. Therefore, if the Way of battle ensures victory, it is permissible to fight even if the ruler says not to fight. If the Way of battle does not ensure victory, it is permissible not to fight even if the ruler says that battle is imperative. Thus, a commander who advances without seeking fame and retreats without avoiding blame, whose sole concern is to protect the people and whose actions accord with the ruler’s advantage, is the treasure of the state.

Regard your soldiers as infants, and you can lead them into the deepest ravines. Regard your soldiers as beloved sons, and they can die with you. But if you treat them generously and cannot employ them, love them and cannot command them, or let them fall into disorder and cannot govern them, they are like spoiled children and cannot be used.

To know that our soldiers can attack, but not to know that the enemy cannot be attacked, is only half the knowledge needed for victory. To know that the enemy can be attacked, but not to know that our soldiers cannot attack, is only half the knowledge needed for victory. To know that the enemy can be attacked and that our soldiers can attack, but not to know that the configuration of the ground makes battle impossible, is only half the knowledge needed for victory. Therefore, one who understands warfare moves without confusion and acts without exhaustion. Thus it is said: Know the enemy and know yourself, and your victory will never be imperiled. Know Heaven and know ground, and your victory can be complete.

Sunzi said: In general, the method of employing troops recognizes dispersive ground, light ground, contested ground, intersecting ground, focal ground, heavy ground, broken ground, encircled ground, and death ground. When feudal lords fight within their own territory, it is dispersive ground. When one enters another’s territory but not deeply, it is light ground. Ground whose possession benefits us and also benefits the enemy is contested ground. Ground across which we can go and the enemy can come is intersecting ground. Territory bordered by three feudal domains, where he who arrives first can gain the support of the multitude under Heaven, is focal ground. When one penetrates deeply into another’s territory and leaves many fortified cities and towns behind, it is heavy ground. Mountain forests, dangerous defiles and obstacles, marshes and swamps, and all roads difficult to traverse constitute broken ground. Ground whose entrance is constricted, whose route of return is circuitous, and where a small enemy force can strike our multitude is encircled ground. Ground on which swift battle means survival and failure to fight swiftly means destruction is death ground. Therefore, do not fight on dispersive ground; do not halt on light ground; do not attack on contested ground; do not let your formations be cut off on intersecting ground; join alliances on focal ground; plunder on heavy ground; keep moving on broken ground; make plans on encircled ground; fight on death ground.

Those of old who were said to be skilled in employing troops could prevent the enemy’s front and rear from reaching each other, his many and few from relying on each other, his noble and lowly from rescuing each other, and his superiors and inferiors from supporting each other. They could make his soldiers separate and unable to gather, and make his troops assemble without being in order. They moved when it accorded with advantage and stopped when it did not. Someone dares ask: “If the enemy is numerous, orderly, and about to advance, how should we meet him?” I reply: “Seize first what he loves, and he will heed you.” Thus, the essential nature of war is speed: take advantage of the enemy’s failure to reach a point in time, proceed by routes he has not considered, and attack where he is not on guard.

In general, the Way of an invading army is this: when it penetrates deeply, its men become united, and the defender cannot overcome them. Plunder fertile country so that the three armies have food enough. Carefully nourish the men and do not weary them; unite their spirit and accumulate their strength. Maneuver the army and devise plans so that you are unfathomable. Cast the troops where they have nowhere to go, and they will die rather than flee. If they are ready to die, how can officers and men fail to exert their utmost strength? When soldiers are deeply trapped, they feel no fear; when they have nowhere to go, they stand firm; when they penetrate deeply, they cling together; when there is no alternative, they fight. Therefore, such troops remain vigilant without being drilled, do what is required without being asked, are close-knit without sworn covenants, and can be trusted without commands. Prohibit omens and banish doubts, and they will go nowhere else until death. If our officers possess no surplus wealth, it is not because they despise material goods; if they possess no surplus life, it is not because they despise longevity. On the day the order to advance is issued, seated officers and soldiers wet their lapels with tears, while those lying down let tears run across their cheeks. Cast them where they have nowhere to go, and they will show the courage of Zhuan Zhu and Cao Gui.

Thus, one skilled in employing troops may be compared to the Swift Snake. The Swift Snake is the serpent of Mount Chang. Strike its head, and its tail arrives; strike its tail, and its head arrives; strike its middle, and both head and tail arrive. Someone dares ask: “Can an army be made like the Swift Snake?” I reply: “It can. The men of Wu and the men of Yue hate one another, yet when they cross a river in the same boat and encounter a storm, they rescue one another like the left hand and the right.” Therefore, hobbling horses and burying chariot wheels are not enough to rely upon. Making courage uniform throughout the army is the Way of government; making both strong and weak serve their purpose is the principle of ground. Thus, one skilled in employing troops leads them by the hand as though directing a single man, because they have no alternative.

The business of a general is to be tranquil and inscrutable, upright and orderly. He must be able to make his officers and soldiers ignorant in ear and eye, keeping them from knowledge. He changes his affairs and alters his plans, keeping others from recognizing them; he shifts his encampments and takes circuitous routes, keeping others from anticipating him. When the commander appoints a task for his men, it is as though he leads them up a height and removes the ladder. When the commander leads them deep into the territory of the feudal lords and releases the trigger, he burns the boats and smashes the cooking pots, driving them like a flock of sheep. They are driven this way and that, and none knows where they are going. To gather the multitude of the three armies and cast them into danger—this is the business of a general. The transformations of the nine kinds of ground, the advantages of contraction and extension, and the principles of human nature must be examined.

In general, the Way of an invading army is this: deep penetration brings unity; shallow penetration brings dispersion. When one leaves one’s own state, crosses the border, and leads an army abroad, that is isolated ground. Ground open in four directions is focal ground. Deep penetration is heavy ground. Shallow penetration is light ground. Ground with strongholds behind and constrictions ahead is encircled ground. Ground with nowhere to go is death ground. Therefore, on dispersive ground I would unify the men’s wills; on light ground I would keep them connected; on contested ground I would hasten up the rear; on intersecting ground I would carefully guard the defenses; on focal ground I would strengthen alliances; on heavy ground I would maintain a continuous flow of provisions; on broken ground I would press forward along the roads; on encircled ground I would block the openings; on death ground I would show them that there is no chance of survival. Thus, the nature of soldiers is to resist when surrounded, to fight when there is no alternative, and to obey when deeply imperiled.

Therefore, one who does not know the plans of the feudal lords cannot enter alliances beforehand. One who does not know the configuration of mountains and forests, dangerous defiles and obstacles, marshes and swamps, cannot move an army. One who does not employ local guides cannot gain the advantages of the ground. He who is ignorant of even one among these several matters does not command the army of a hegemon or true king. When the army of a hegemon or true king attacks a great state, that state’s multitudes cannot assemble; when his might bears down upon the enemy, the enemy’s allies cannot unite. Therefore, he does not contend for alliances under Heaven, nor does he foster the authority of others under Heaven. He trusts his own private designs and brings his might to bear upon the enemy; thus he can take the enemy’s cities and overthrow the enemy’s state. Bestow rewards that transcend established law and issue commands beyond ordinary government. Direct the multitude of the three armies as though employing a single man. Set them tasks, but do not explain them in words; show them the advantage, but do not tell them the harm. Cast them upon ground of destruction, and only then will they survive; sink them into death ground, and only then will they live. Only after the multitude has been plunged into danger can it determine victory or defeat. Thus, the business of warfare lies in feigning compliance with the enemy’s intentions, concentrating against him in a single direction, and marching a thousand miles to kill his commander. This is called accomplishing affairs through skill and ability.

Therefore, on the day the government resolves to mobilize, close the passes and break the tallies, permitting no enemy envoy to pass. Deliberate sternly in the ancestral temple in order to execute the plans. When the enemy opens a door, you must rush through it. Seize first what he loves, and subtly adjust your timing to his. Follow the marked line in accordance with the enemy in order to decide the business of battle. Thus, at first be like a maiden, and the enemy will open his door; afterward be like a hare loosed from the snare, and the enemy will be unable to resist.

Sunzi said: In general, there are five kinds of fire attack. The first is burning men; the second, burning stores; the third, burning baggage trains; the fourth, burning arsenals; the fifth, burning lines of transport. To carry out a fire attack there must be a means, and incendiary materials must always be prepared. There are proper seasons for setting fires and proper days for raising them. The proper season is when the weather is dry. The proper days are when the moon is in the constellations Basket, Wall, Wings, or Crossbar. These four lunar lodges mark days when winds arise.

In every fire attack, one must respond according to the transformations of the five fires. When fire breaks out within the enemy’s camp, respond swiftly from without. If fire breaks out but his troops remain quiet, wait and do not attack. Let the fire reach the height of its power; if you can follow it with an attack, do so, and if you cannot, stop. If fire can be set from without, do not wait for it to be set within; ignite it at the proper time. When fire is set upwind, do not attack from downwind. A wind that blows long during the day will cease at night. Every army must understand the transformations of the five fires and guard for the proper calculations. Thus, one who assists an attack with fire is enlightened; one who assists an attack with water is powerful. Water can cut the enemy off, but cannot deprive him of everything.

To win battles and take objectives without cultivating the fruits of those achievements is disastrous; this is called “wasteful delay.” Therefore it is said: An enlightened ruler must consider it, and a good commander must cultivate it. If there is no advantage, do not move; if there is nothing to gain, do not employ troops; if there is no danger, do not fight. A ruler must not raise an army out of anger; a commander must not bring on battle out of resentment. Move when it accords with advantage; stop when it does not accord with advantage. Anger can return to joy, and resentment can return to pleasure, but a destroyed state cannot return to existence, nor can the dead return to life. Therefore, the enlightened ruler is cautious, and the good commander is vigilant. This is the Way to keep the state secure and the army whole.

Sunzi said: In general, when an army of one hundred thousand is raised and sent on a campaign a thousand miles away, the expenses of the common people and the outlays of the public treasury will amount to a thousand pieces of gold each day. There will be turmoil at home and abroad; men will collapse from exhaustion on the roads; and seven hundred thousand households will be unable to pursue their work. Armies may confront each other for several years to contend for victory on a single day. Yet if one begrudges ranks, emoluments, and a hundred pieces of gold and therefore remains ignorant of the enemy’s condition, this is the height of inhumanity. Such a man is no general of the people, no assistant to his ruler, and no master of victory. Thus, what enables enlightened rulers and worthy commanders to move and conquer others, achieving success beyond the multitude, is foreknowledge. Foreknowledge cannot be obtained from ghosts and spirits, cannot be inferred by analogy from events, and cannot be verified by calculations. It must be obtained from men who know the enemy’s condition.

Therefore, there are five kinds of spies: local spies, inside spies, turned spies, doomed spies, and surviving spies. When all five kinds are active together and no one knows their methods, this is called the “divine web,” and it is the treasure of the ruler. Local spies are recruited from among the enemy’s local people. Inside spies are recruited from among the enemy’s officials. Turned spies are recruited from among the enemy’s spies. Doomed spies carry deceptive information abroad: we let our own spies know it and have them transmit it to the enemy’s spies. Surviving spies return to report.

Thus, among all affairs of the three armies, none is more intimate than relations with spies; no rewards are richer than those given to spies; no affairs are more secret than matters of espionage. Without sagely wisdom, one cannot employ spies; without benevolence and righteousness, one cannot command spies; without subtlety and discernment, one cannot obtain the truth from spies. Subtle indeed! Subtle indeed! There is nowhere that spies cannot be employed. If a matter of espionage is heard before it has been carried out, both the spy and the person to whom he disclosed it must die.

Whenever there is an army you wish to strike, a city you wish to attack, or a person you wish to kill, you must first know the names of the defending commander, his attendants, his ushers, his gatekeepers, and his chamberlains. Order your spies to investigate and learn them all. Enemy spies who have come to spy upon us must be sought out. Lure them with profit, guide them, and lodge them; thus turned spies can be obtained and employed. Through the knowledge gained from them, local spies and inside spies can be found and employed. Through the knowledge gained from them, doomed spies can carry deceptive information to the enemy. Through the knowledge gained from them, surviving spies can return as scheduled. The ruler must know the affairs of all five kinds of spies, and this knowledge must come from turned spies. Therefore, turned spies must be treated with the utmost generosity.

Formerly, when Yin arose, Yi Zhi was in Xia; when Zhou arose, Lü Ya was in Yin. Therefore, enlightened rulers and worthy commanders who can employ men of supreme wisdom as spies will surely accomplish great achievements. This is the essential matter in warfare, upon which the three armies rely in order to move.