This passage sets camping standards: pick high, sunny, fertile ground to keep troops healthy. It warns against six deadly terrains, lure enemies near them, and thoroughly search nearby woods and wetlands to guard against hidden ambushes and spies.
This passage lays out camping and combat rules for four terrains: mountains, rivers, marshes and plains. It details optimal positions and tactics like striking foes halfway across water. Mastery of such geographic edges enabled the Yellow Emperor to defeat rival tribal lords.