A nation will eventually expand to more regions. The first one holds its capital city, while other regions can provide a variety of natural resources and different biomes. Spreading out development also helps improve infrastructure efficiency, and subsistence is usually more efficient in unexploited lands.
Here we have 2 cities on 2 separated landmasses
The city has claimed the entire island but has also extended its influence off the coast to the northeast, reaching another island. Water tiles are much cheaper to claim and maintain, but they require sea-projection points. We can see how the relief hinders the administration's reach. The red areas have the lowest administration efficiency.
But this city has a strong naval tradition. Infrastructure on the coast and a special building in the capital (seaport) generate enough sea-projection points to claim the entire coastline of the continent.
This city has 3 sea-projection points and can control 3 sea tiles without penalty
Administration spread is much more efficient at sea than on undeveloped land (without infrastructure development), meaning that even the remote coastlines to the west are now properly administered.
Administration efficiency is very important as it represents the control a nation has over a region and its population. It affects corruption, taxes, and the Political Point (PP) balance. Usually, low administration is also a sign of poor supply routes, which affects industry efficiency and hinders internal migration.
Osley has claimed a large territory. Each territory costs a lump sum of PP (Political Points) and also requires administration maintenance. This tiny nation would never be able to administer such a large territory without having crippling corruption. Administration is produced from buildings in the capital city, and maintenance is reduced through infrastructure and policies.
The administration cost of a tile is mainly determined by the population and the administration "pathfinding" cost to the capital (where infrastructure, relief, and flora play a major role).
The migration attractiveness overlay tells us a lot. Osley relies mostly on subsistence, and its capital's region offers many more opportunities than these untamed territories. Bear in mind that a single tile is quite a large area by itself.
However, the uranium to the northwest, petrol to the north, iron to the west, and coal to the southwest offer good opportunities to establish robust industry.
Migration attractivness overlay