Sun Tzu turns to encamping the army and observing signs of the enemy. Pass quickly over mountains and keep near valleys. Camp in high places, facing the sun. Confined places, tangled thickets, quagmires, and crevasses are to be left with all possible speed and not approached. Keep away from such places and get the enemy to approach them. Face them, and let the enemy have them on his rear. If hilly country, ponds with aquatic grass, hollow basins filled with reeds, or woods with thick undergrowth lie near the camp, they must be routed out and searched, because men in ambush or insidious spies are likely to be lurking there.
The enemy's quiet and noise then become readable. When he is close at hand and remains quiet, he is relying on the natural strength of his position. When he keeps aloof and tries to provoke a battle, he is anxious for the other side to advance. If his place of encampment is easy of access, he is tendering a bait. Movement amongst the trees of a forest shows that he is advancing. Screens in the midst of thick grass mean he wants to make the other side suspicious. Birds rising in flight are the sign of an ambuscade. Startled beasts indicate that a sudden attack is coming. Dust in a high column means chariots. Dust low and spread wide betokens infantry. Dust that branches out shows parties sent to collect firewood. A few clouds of dust moving to and fro signify that the army is encamping.
Words and bodies are read the same way. Humble words together with increased preparations mean he is about to advance. Violent language and a show of driving forward mean he will retreat. Peace proposals without a sworn covenant indicate a plot. Hunger shows when soldiers lean on their spears. Thirst shows when the men sent to draw water drink before they carry it back. An advantage he sees and does not take means the soldiers are exhausted. Birds gathering on a spot mean it is empty. Whispering in small knots points to disaffection in the ranks. Too many rewards mean his resources are at an end. Too many punishments mean dire distress. The hardest sign to mistake is the army that feeds its horses with grain, kills its cattle for food, and does not hang its cooking-pots over the camp-fires: those men will not return to their tents, and they mean to fight to the death. Envoys who arrive with compliments wish for a truce. Troops that march up angrily and then simply remain facing ours, neither joining battle nor going off, call for vigilance rather than a rush.
If one's own troops are no more in number than the enemy, that is amply sufficient, and it only means that no direct attack can be made. What can be done is to concentrate all available strength, keep a close watch on the enemy, and obtain reinforcements. He who exercises no forethought but makes light of his opponents is sure to be captured by them. If soldiers are punished before they have grown attached, they will not prove submissive, and unless submissive they are practically useless. If, once they have become attached, punishments are not enforced, they will still be useless. Soldiers must be treated in the first instance with humanity, but kept under control by means of iron discipline. That is a certain road to victory. If in training commands are habitually enforced, the army will be well-disciplined. If a general shows confidence in his men but always insists on his orders being obeyed, the gain will be mutual.
