Everything about trade in Asphodel flows from one geographic fact — the central ocean is impassable. The Maw of the Abyss sits dead centre, radiating corruption, madness, and monsters. Ships that attempt open-ocean crossings don't return.

So all trade follows the coastlines of the three continents like blood through veins — threading through three main corridors. Coastal cities have disproportionate power. A city with a good harbour can rival inland kingdoms ten times its size. Control a strait, control the world's wealth.