水攻防禦
Countering Water Attacks
城內塹外周道，廣八步。備水謹度四旁高下。城地中徧下，令耳其內，及下地，地深穿之，令漏泉。置則瓦井中，視外水深丈以上，鑿城內水耳。並船以為十臨，臨三十人，人擅弩，計四有方，必善以船為轒轀。
Inside the city, a peripheral road surrounds the inner trench, eight paces wide. To defend against water attack, carefully measure the elevation of all four sides. If the ground inside the city is uniformly low, dig drainage channels inward. Where the ground is lowest, dig deep to drain the springs. Place clay pipes in the wells. When the water outside the wall rises above one zhang, bore drainage holes through the inner wall. Lash boats together in groups of ten to form assault platforms, each platform carrying thirty men, each man equipped with a crossbow. Plan for four cardinal directions. One must be skilled in converting boats into armored assault vehicles.
Notes
Water attack (水攻) was a devastating siege technique involving the diversion of rivers to flood a city. The Mohist counter-measures focus on internal drainage systems and the conversion of boats into mobile fighting platforms for counterattack within flooded areas.