How to Roleplay EU4

Topics that a nation can RP about

The aspects of your nation that is an overall umbrella of your situation

Religion
Culture
Government type
Estates

Things that should have a major impact on your narrative

Alliances
Royal marriages
Rivals

Things that happens that can impact your current narrative

Events
Leader traits, religion and culture
Dynasty change
Development
New Idea groups
New unit types on land and sea
New government reforms
Estates
Trade, trade goods and trade deals
Protecting trade
Privateering

Things that are not an RP path

The game offers a lot of opportunities based upon the real world history of the EU4 timeline. When we play our roleplaying games, we sign up to the historical accurate situation of 1444, what happened before that is lore that we must acknowledge. What happens after is more of an open book. The many opportunities the game offers are not something people should expect to achieve or aim towards. If the story we create in our games allows for similar situations, that is great, but it is not something we should expect. 

Formables
Signing up to play as Holland does not create a right to form the Netherlands. Also the player should not expect it to happen. The player signs up to play as the Imperial State and Country of Holland, that got into internal conflicts during the Hook and Cod Wars, that led to Phillip the Good, the Duke of Burgundy to gain control of it as a vassal. Whatever happens after the game starts is an open story we write together.

Mission trees
The game offers some long, powerful and interesting mission trees. While there is lots of flavor in them, close to 100% of all completed missions are never roleplayed upon and just serves as a singleplayer experience, during a multiplayer game. Aiming to play towards completing your missions CAN be roleplayed upon, but it is not an RP path that you MUST undertake. Optimally, you create your own story and not follows the historically inspired paths. We are not playing a history recreation simulator.

Decisions
Almost all nations in the game has some decisions to take and others many. Just like mission trees, these can be roleplayed, but they should not direct your story, create your own. Anyone can press a button.

Expected events
Many of stories that unfolds by in the game happens through events. We all know them, the Iberian Wedding, The Surrender of Maine and so on. They might happen and they might not. It is not okay to go into the game and roleplay towards them to fire in your expected fashion. Sure, we all know that once Naples is independent the Baronial Revolts might fire and Naples get an event to either lose stability and spawn lots of rebels or decide to fall under France in a Personal Union. To play as Naples and hope for this event to fire is not a legal RP path. If it happens, it happens. For the event to happen requires Naples has less than 90 legitimacy, to wiggle your way into expected events to land in your favor is considered meta gaming and players who does this will be punished severely.

Mercenary states
We have seen some people play as mercenary states. The idea is in itself not bad, there is lots of great roleplay and fun in the story of selling powerful soldiers. However, a nation in the period of the EU4 timeline consists of so many things, ranging from the everyday population, its faith, standard of living, the different powerful factions within the nation and so many more aspects. To define a nation as a mercenary state is not realistic. You should roleplay the individual mercenary company as a faction within your nation, not as your nation. The company might have their own agenda, beliefs and motivations. Allow outside nations to impact them. Maybe another nation wants to make a royal marriage, but in RP it is between the general of the company and a princess. Or some rich person is tired of their influence in his shenanigans and wants to pay the company to retire with a massive sum of gold.