Austria is the Emperor at the start of the game. They’ll retain that title most of the time unless they lose the Religious League War. Austria also has access to the most number of modifiers to diplomatic reputation. This makes them more likely to win the Imperial election. So:
If you’re seeking admission into the HRE, you’ll want to befriend Austria. If you want to be the Emperor, you should undermine Austria at every possible opportunity.
Method 1: Getting Admitted
You can join the Empire if: Opinion is capped at 200. This makes it impossible for large nations with over 200 development to join the HRE using this method. There are several ways to improve another nation’s opinion of you. Since you can’t go over 200 development, some diplomatic actions won’t be accessible to you, especially the Great Power actions. The ones that you can do are: Note: The Economy actions can become expensive. The money needed to get the max opinion bonus is relative to your target’s monthly income. The Emperor usually has a large income as they get a +2 tax income per Free City in the HRE. Once the Emperor has a high enough positive opinion of you, you can click on the “Join HRE” button in the HRE UI.
Method 2: Getting Elected
All Catholic monarchies with an adult ruler are eligible to become the Emperor, even if they’re not an HRE member. Note: Protestants and Reformists can be eligible too if their side has won the Religious League War. If that war results in the “Peace of Westphalia” event, any Christian nation — including Orthodox and Coptics — can become the emperor. To become the Emperor, you just need to have the HRE electors vote for you. There are always 7 HRE electors. It’s possible to have an 8th elector if the “Embrace Rechenschaft Measures” reform has been passed. However, the HRE usually disintegrates before that can happen. If an elector loses their privilege or ceases to exist, the Emperor will appoint another HRE member to replace them. The conditions that affect how electors vote are: You can check the current electors and who they’re voting for in the HRE UI. You can also view the status of your candidacy by hovering over the elector’s coat of arms. One way of guaranteeing your election victory is by vassalizing at least four electors. Improve relations with them for a bit until they like you more than the other candidates. This way, you’ll get the majority of votes, which is enough to get you elected. A great time to pursue this path is during the Age of Reformation. The turmoil in this Age is centered inside the Empire. This can weaken both the incumbent Emperor and the Empire as whole. Once you’re the Emperor, the “Join HRE” button in the HRE UI will become clickable.
