Themes: Terrain
Leveraging the Environment
- 地者，高下、远近、险易、广狭、死生也。 — 始计
- 九地之变，屈伸之利，人情之理，不可不察。 — 九地
- 夫地形者，兵之助也。 — 地形
- 夫兵形象水，水之形，避高而趋下，兵之形，避实而击虚。 — 虚实
The use of terrain is covered in several chapters in The Art Of War. In different levels of abstractions, these can represent physical grounds or situations that one encounters, and which guide one’s actions in the course of battle. An effective general leverages the external environment to her advantage in securing or projecting her forces. She identifies and directs her army, intuitively like water, to occupy positions of strength and concentrate their forces against her enemy. Terrain frames and affects the nature of the battle. It cannot be easily altered during the course of battle but given sufficient time and resources one can do so, such as fortifying one’s positions to gain an upper hand.
- 圮地无舍，衢地交合，绝地无留，围地则谋，死地则战。 — 九变
- 用兵之法，有散地，有轻地，有争地，有交地，有衢地，有重地，
有圮地，有围地，有死地。 — 九地
There are ten types of grounds or situations:
争 and 衢 are strategically valuable grounds where one seeks to occupy it first to reap geographical or political advantage.
交 are commonly accessible grounds with low barriers to entry. One cannot establish strong tactical defence against the enemy nor gain meaningful strategic advantage.
圮, 围, 死 and 绝 are dangerous grounds where an army’s movement is hampered, dominated by the enemy or lack supplies to subsist. One needs to exercise caution, either to avoid, traverse quickly, or to resort to stratagem to extricate herself from these situations.
散, 轻 and 重 are dependent on the level of penetration into enemy territory, or ease of retreat into security. These have implications on soldiers’ will and morale.
- 地形有通者，有挂者，有支者，有隘者，有险者，有远者。 — 地形
Terrain are also defined by their physical, geographical features and the relative advantages conferred upon, or constraints imposed, on the army. These are not mutually exclusive, and could describe the earlier ten situations discussed.
隘 and 险 confer significant advantages on the occupier and severe disadvantage to one entering it thereafter. One seeks to occupy it first or avoid head-on engagement with the enemy. These also represent 争.
通 and 挂 are terrain where both sides can access with ease. The main consideration in 通 is the offensive. One arrives first to occupy the most advantageous feature and await combat. The main consideration in 挂 is defensive as retreat is difficult. One avoids committing her forces before she is confident of victory.
支 and 远 are grounds on which the army that initiates battle has a disadvantage. One entices the enemy to commit her forces first and engages her when she is in a vulnerable position.
