EU4's Interface, also called user interface (UI), or graphical user interface (GUI), has a number of specific screens and visual elements. This article will focus on the pragmatic purpose and utility of the interface (as opposed to the stylistic elements).
The Main Menu is the first screen players see after the game loads at start up, and where players return to after they leave their in-progress games. It shows the main map along with some tool bars, buttons and information along the bottom.
Lower left corner
- Game Version
- Single Player to choose a single player game
- Multi Player to choose a multiplayer game
- Tutorial to play a tutorial game
Lower right corner
Upper left corner of main map
Provides a heraldic representation of your country. The shield is not just decorative. It actually provides a pop-up view of information about your country.
A gilded row to the right of the shield, showing an number of elements:
- Treasury - a gold coins icon with a + or - to show whether you have a positive or negative balance. Hovering over this will display a tooltip telling you your monthly income, and a quick explanation about why you are in the black or in the red.
- Manpower - this is your reserve of soldiers, with a value of 0 or greater representing how many individuals you can recruit or reinforce into your armies. Hovering over this will display a tooltip of how many men your current armies require to prevent attrition, the maximum reserves of available manpower, and how much this value will increase or decrease over the next month.
- Stability - showing a scale of +3 (very stable) to -3 (very unstable). The tooltip will explain the benefits or penalties you receive based on your current stability level.
- Prestige - on a scale of +100 (very prestigious) to -100 (utterly insignificant). Hovering over this will explain your current level, what is influencing it upwards or downwards, and the benefits and penalties you receive based on your current prestige level.
- Legitimacy - on a scale of 0 (no legitimacy) to 100 (very legitimate); this section is called Republican Tradition for countries with a Republican form of government. Hovering over this will explain the contributors to your Legitimacy status, and the benefits and penalties you are receiving as a result.
These show four different types of specialists, called envoys who can be sent on missions for your country.
- Merchants - This shows a two number figure, in the form "X/Y", where "X" is the number currently available for assignment, and "Y" is the total number available to the country. The maximum number varies depending a nation's idea groups. For example, if it said "0/2", there are no currently-available merchants out of 2 total. Merchants can be dispatched to trade nodes to steer income to your country's treasury.
- Colonists - a similar scale of "X/Y"; this often begins the game of "0/0" until the player develops the technology for establishing colonies. Colonists can be sent on colonization missions around the world to add new territory to your country.
- Diplomats - similar "X/Y" scale. They can be sent to improve relations with other countries, or conduct covert actions working against them. Diplomats are dispatched to interact with foreign powers, where they may handle short-term assignments, such as signing treaties, negotiating marriages, and delivering insults, after which they will return. They may also be given long term assignments, such as building stronger relationships or forging claims on certain lands you would like to possess, in which case they remain on site until recalled or until their task is complete.
- Missionaries - similar "X/Y" scale. They can be dispatched to provinces where the local population does not share the same faith the state religion and try to convert them. They remain there until the task is complete.
A silver flowing banner below the gilded Information Bar shows the name of your country, plus your currently-accumulated Monarch Points, of three different types:
- Administrative Power - symbolized by a scroll document icon.
- Diplomatic Power - symbolized by a dove icon.
- Military Power - symbolized by a crossed swords icon.
Lower right corner of main map
Holy Roman Empire Interface
- Main article: Holy Roman Empire interface
- Main article: The Curia
Catholic countries participate in a bribery competition/election for control of the papacy.
- Main article: Minimap
The minimap is a small representation on the world on the screen's lower right corner. In it, a box shows what part of the world is being displayed on the game screen. By using the mouse, one can click to a remote part of the world or adjust the part of the map being displayed.