* '''In [[war]]''': If a capital is occupied during a war, it will count for a greater [[warscore]] because of its value. Some [[casus belli]] use either the attacker's or the defender's capital as the wargoal. Occupying the enemy capital will increase the desire for peace of the AI, allowing you to potentially claim more in the peace deal. Just sieging the enemy capital also reduces War Enthusiasm for the AI. Taking the capital in a peace deal costs 20% more warscore.
* '''For [[trade]]''': Trade is automatically collected from the node containing the main trade port, even without a merchant (although a merchant will boost the income received). Collecting from trade in other nodes reduces one's trade power there by 50%. A nation's main trade port is always in the same province as the capital at the beginning of the game. Players
owning the [[Wealth of Nations]] expansion may move their main trading port to a new province at the cost of 200 Diplomatic points.* Players owning the [[Common Sense]] expansion have development cost reduction in their capital city, proportional to the country-wide development. For every 20 development, the capital gets a 1% reduction, up to a maximum of 50% (1000 total development).
* '''For government [[envoy]]s''': [[Colonists]] and [[diplomats]] all return to the capital when they are unassigned, and the time taken to return depends on the distance from their target to the capital.