Definition
The nine situations (or nine kinds of ground) is Sun Tzu's most elaborate typology of terrain, developed in Topic 11 of The Art of War. It extends the six conformations of Topic 10 by adding psychological classifications to the geographic ones. The nine grounds are:
- Deserters' ground — a lord in his own home territory; soldiers can easily slip away.
- Lightly-taken ground — shallow incursion into enemy territory.
- Contested ground — ground whose occupation confers advantage to either side.
- Meeting ground — equally accessible to both sides.
- Crossroad ground — borders of neighbouring states converge; first to arrive secures supporters.
- Never-lightly-taken ground — deep incursion with enemy strongholds at your back.
- Difficult ground — mountains, forests, marshes; hard to cover.
- Ambush-prone ground — narrow entrances and exits where small forces threaten large ones.
- Deadlands — terrain where survival requires ferocious fighting.
Each ground has a default rule: never fight on deserters' ground; never tarry on lightly-taken; never attack first on contested; make allies on crossroads; fight like hell in the deadlands. Together, the nine form a complete operational map.
Why it matters
How it works
The typology is meant to be diagnostic, not memorised. Before a major move, the commander asks: which of the nine situations am I on? The answer dictates the posture. The same forces that should "press on without stopping" on difficult ground should "make allies" on crossroad ground and "fight like hell" in the deadlands.
The deepest of the nine — and the topic's psychological centrepiece — is the deadlands. Sun Tzu's instruction is unsettling: throw your troops into situations with no way out, and they will give everything. The "sudden striker" snake of Mount Heng illustrates the principle — every part of the body defends every other part automatically when survival is at stake. The doctrine has been applied (and abused) across military and corporate contexts ever since.