The ninth floor's grand war: nine factions ringing Larracos build armies of 15,000 and clash for bragging rights once the crawlers arrive.
The Faction Wars are the ninth-floor endgame Mordecai details for Carl. Nine factions occupy nine 'petal' territories around the inverted-cone dwarf city of Larracos (the previous winner may choose their start, most picking the pre-fortified 'King's Point'). Each begins with 15,000 troops — mostly non-respawning NPCs, plus a small number of protected outsider 'tourists' (a rich faction like ~200, a poor one like the Blood Sultanate ~20; every outsider added removes one NPC).
From the sixth floor's opening they buy gear from crawlers and hire mercenaries won through games and gambling; they build fortifications and grind their officers in the surrounding forests, forbidden to fight each other until the crawlers arrive — at which point lethality (for the otherwise-teleported-to-safety tourists) and the real war begin, waged for a cash prize and, mostly, bragging rights. Carl's intense interest in its mechanics signals it figures into his plans.
A nine-petaled flower of faction territories ringing the buried city of Larracos, dotted with armies, forts, and forests.
The ninth-floor war between nine army-building factions — the dungeon's grand strategic endgame.
Also appears in books you've already read — spoiler-safe to their endings: