X. Terrain

These are the words of Master Sun:

There are six types of terrain:

  1. Open terrain
  2. Constricting terrain
  3. Balanced terrain
  4. Narrow terrain
  5. Steep terrain
  6. Boundless terrain

Terrain that both sides can travel across freely is called "open terrain". In this type of terrain, you will win an advantage when the battle begins if you can be the first to capture a sunny hill that allows open supply lines.

Terrain which is easily abandoned but hard to return to is called "constricting terrain." If the enemy is unprepared, you can attack from a position in constricting terrain and defeat the enemy. However, if the enemy is prepared for your attack and you fail to win decisively, retreat is made hard by the constricting terrain. A failed attack in constricting terrain can therefore be calamitous.

If neither side gains an advantage from making the first move, it is called "balanced terrain." If you occupy a position in balanced terrain, you should refrain from attacking and should instead retreat and tempt the enemy into attacking you. When the enemy has put his army into motion to attack you, then you gain an advantage by counterattacking.

If you occupy narrow terrain, you should guard it closely and wait for the arrival of the enemy. If, however, the enemy has arrived before you and taken up position in a narrow pass, you should not attack unless the enemy is only defending the pass with a minor force.

If you arrive before the enemy in steep terrain, you should occupy a sunny position on the high ground and wait for the enemy to arrive. If the enemy has arrived before you, you should not seek him out, but rather pull back and seek to lure him away from his advantageous position.

If two armies of similar size are facing each other in boundless terrain, it is hard to force a battle, and this is not to your advantage.

These are the tactical principles connected to the six types of terrain. You should study them closely.

An army can suffer misfortunes that are not natural but are due entirely to its commander.

These misfortunes are as follows:

  1. Desertion
  2. Disobedience
  3. Disintegration
  4. Destruction
  5. Dissolution
  6. Disarray

If you pit your army against an army ten times greater than yours, your troops will desert you.

If the rank and file is too strong and your officers are too weak, the result will be disobedience.

If the officers are too strong and the rank and file is too weak, the result will be disintegration.

If the ranking officers are hot-tempered and do not obey the orders of their commander, they can be enraged by the enemy and begin the battle before their commander has had a chance to study whether he is in a position from which attack will be advantageous. The result of such rashness will be the destruction of the whole army.

If the commander of the army is weak and without authority, if his orders are unclear, and if duties are not assigned properly and formations are poorly organized, the officers and the rank and file will have no one to follow, and the result will be dissolution.

If the commander is unable to properly gauge the strength of the enemy's force and orders a lesser force to attack a greater force, or if he pits a weak division against a strong division, or if he does not post his elite soldiers at the front of the army, the result will be disarray.

These are the six ways in which you can suffer a defeat. You should study them closely.

The greatest allies of a soldier are the natural characteristics of the terrain, while the marks of a great commander are his ability to gauge his opponent, his mastery of the implements of victory, and his ability to analyze problems, dangers, and distances. He who understands these things and is able to use this understanding in the field will win many battles. He who is unaware of this knowledge or who fails to use it in the field will face only defeat.

If victory is assured, you must engage in battle even if your sovereign has commanded you to retreat. If defeat is assured, you must retreat from battle even if your sovereign has commanded you to attack. A commander who advances without seeking acclaim and who retreats without dreading dishonor, whose only concern is to defend his country and serve his sovereign, is to be regarded as the most precious jewel in the Realm.

Think of your troops as your children and they will follow you through the deepest of valleys. Think of them as your own cherished sons and they will stand with you even in the face of death. However, if a commander is generous but without ability to use his authority, good-hearted but incapable of enforcing his orders, and powerless to quell disorder, then his soldiers are like spoiled children - useless in any practical sense.

You are only halfway to victory if you know that your own troops are ready to attack but you are unaware of the enemy's preparedness. If you know that the enemy is not prepared for an attack but do not know whether or not your own troops are ready to attack, you are still only halfway to victory. If you know that the enemy is not prepared for an attack and also know that your own troops are ready to attack, you are still only halfway to achieving victory if you do not know whether the terrain is suitable for attacking.

This is why the experienced soldier, once on the move, is never irresolute; he does not break camp without a firm idea of where he is going. This is the origin of the old proverb: "Know thyself and thine enemy and victory will be thine; know heaven and earth and thy victory will be complete."