A core province of a country is a province that is viewed internationally as a legitimate claim of that country. Core provinces are also called "cores", "national provinces", and sometimes "shield provinces".
Effects of Core Provinces
Core provinces have many effects in the game. Here is a partial listing:
- If any of a country's cores are owned by a second country, the first country has a casus belli on the second.
- A country never suffers nationalism revolt risk in its core provinces.
- Core provinces may be demanded in a peace treaty, at half the usual warscore cost. Even if not occupied, they can be demanded at double the usual warscore cost.
- When a country takes core provinces in a peace treaty, it does not accrue badboy as a result.
- Core provinces usually generate more income (from the province tax and also census tax) than other provinces.
- Core provinces are less affected by war exhaustion.
- Owning additional core provinces may help a player defend against being forced to agree to a peace deal. A player is forced to agree to all peace demands when the player does not control any of his owned cores nor any provinces land-connected to his capital. The same is not true for the AI.
Identifying a Country's Core Provinces
You can see your country's core provinces by the coat of arms displayed atop that province on the map, when using the political map mode (accessable by clicking on the crossed flags emblem above the mini-map).
You cannot see the core provinces of another country in the game, except by saving it, loading up as the other country, then using the political map.
Sources of Cores
The core provinces of a country generally do not change. When the game starts each country is given a set of core provinces defined in the scenario. When a new country enters the game, via revolt, freeing a vassal, or an independence event, it gets a set of cores defined for it in revolt.txt. See the new country creation article for details.