Europa Universalis: Rome/Nation Overview

The Nation Overview page shows a general summary of your nation, presenting the name of the government in effect, the current ruler, current national ideas, and a quick view of the provinces.

Government types
Governments at the time have one of three categories: Tribal, Republic, and Monarchy. These are then divided into a subset of government types, which have minor changes on the behavior of government.

National ideas
On nation overview, you may choose some national ideas. These national

You may change a national idea. The change is free if the new idea matches the ruler's faction, but otherwise costs 3 stability.

The national idea slots are generally associated with a specific type of idea. While there is no explicit penalty for a mismatched idea, you need to have all three match in order to get the associated bonus with the government.

Ruler
The ruler at the top-right corner shows the current ruler. You can hover the mouse over the image to get a summary of stats, and click the picture to view character details.

The ruler's faction provides a specific bonus to the nation. However, the populist faction provides a penalty.