At its worst, Europa Universalis IV is a game of unchecked conquest. It shares a common problem with many grand strategy games, namely the fun struggle to survive and grow as a state is gradually replaced with a lengthy period of easy conquest and ‘cleaning up.’ EUIV’s timeline spans 400 years (1444-1821), but it’s rare for most players to ever get beyond 1650. By then you are the strongest: alliances can be broken with impunity, neighbours devoured and coalitions smashed. Without the challenge of the early and mid game, EUIV and other titles like it devolve into rote warring to expand your territories. Interesting decisions evaporate, and as long as you’re clever enough not to let a massive coalition form, you will be unchallenged. Playing as Austria is the antidote to those problems. It provides a unique, long-lasting challenge which is different from the experiences of other, more conventional states.
As Austria, you have the same freedom as any other state in EUIV. You can craft alliances and war as you like with the added detail that you begin the game in 1444 as Holy Roman Emperor. Being the Emperor gives you a range of direct benefits like an extra diplomat, an extra diplomatic relation slot (both useful to maintaining your position), an extra military leader and crucially increased manpower and force limit tied to the number of HRE member states. Manpower is a constantly replenishing pool in EUIV, representing the number of able-bodied men in your nation. Training a regiment decreases it by 1,000 and all losses your regiments suffer are eventually replenished from the pool. The size of the pool and the speed at which it replenishes depends on the size of your nation and the value of its provinces: to have no manpower is bad both because you can’t train new regiments/your existing regiments can’t reinforce and because it represents a great time for the AI to attack. Losses in battle will be more permanent, and damaged regiments fight at reduced strength. Meanwhile, your force limit represents the upper limit of regiments you can train without paying an extra penalty for maintenance. Both stats are important to determining the strength of a nation in EUIV, and it’s shrewd design to link the Emperor’s bonuses in these areas to the number of princes in the HRE. To compete with the much larger nations surrounding Austria like France, Spain and Poland-Lithuania these military bonuses are vital. To maintain them, Austria must fulfil its duty as the Holy Roman Emperor.
The Holy Roman Empire is not a united political entity. It is, rather, a confederation of (mostly) small states in central and northern Europe and Italy. They fight among themselves, swapping land and conquering each other as often as they war with outsiders. For Austria to maintain their maximum bonuses to manpower and force limit, the number of princes must be as high as possible which leads to an objective unseen elsewhere in grand strategy. Rather than trying to acquire land, Austria’s primary goal is to maintain imperial integrity. Austria needs to halt opportunistic advances by France and Burgundy in the west, for instance, who frequently seek to swallow the HRE’s microstates. To succeed at the game, Austria does not want to grow exponentially but rather maintain a status quo which keeps them powerful. They get some help in this regard since they’re automatically called into wars which have been declared by a non-member of the HRE on a HRE prince. Sometimes this means Austria and a one-province state versus France (not a good situation to be in) but more frequently it’s a clutch of small German princes versus an outside aggressor, since the attacked principality also call on their allies. These wars, especially early, have a flavour which is not exactly David versus Goliath but several Davids and a junior Goliath versus Goliath. Your imperial allies hopefully swarm Burgundy or Spain or any other enemy, besieging their fortresses and merging their numerous, small armies into yours to fight larger foreign threats. The adversity and unpredictability of these wars is wonderful. There’s little better than marching an army into a fight your allies are narrowly losing to turn the tide or, alternatively, having one ally stand around like a dummy while the rest of you get slaughtered.
This is only half the Emperor’s duties, though, since you also don’t want the HRE’s states to swallow each other. An Emperor concerned only with conquest either within the HRE or to the east in will quickly find their bonuses diminish as the 55 states which exist in the HRE in 1444 are compacted into a few dominant players. The only way to halt this trend is to intervene yourself. When a prince is conquered, the Emperor can declare war on the aggressor with a special ‘Imperial Liberation’ casus belli which makes it easier for the Emperor to release the captured state when they’ve won the war. If it sounds destructive to declare war within your own Empire, that’s because it frequently is. Rarely is it a case of beating up just some puny theocracy. As I mentioned, they have allies and you probably have allies and these disputes over keeping the amount of princes at the maximum number can be devastating, wrecking your relations with neighbours and electors.
The HRE is elective. There are seven electors who each cast one vote for the next Emperor. After your first character dies, you must have the most votes (but importantly not necessarily a majority) to have your heir declared emperor. The electors can (and frequently do) vote for themselves, and Austria itself doesn’t have a vote meaning it requires delicate diplomacy to secure a plurality. This never becomes easy and Bohemia will almost always challenge you for leadership. So in short when you want to declare war, you have to make a calculation. Is this war going to sour your relations with this or that elector? And is it worth it? Frequently, it’s not. It’s not principled to allow states to be swallowed up by electors and their allies, but are you really going to risk a long and painful war, not to mention losing the election, just to free Baden? Austria has to strike a balance between keeping the princes numerous and imperial integrity strong and protecting their own position. While this is also true of other nations who want to lead the HRE, the fact that Austria has no votes itself means its particularly vulnerable and the game is more interesting for it.
There is another advantage to successive elections of your descendants, and another goal beyond maintaining the status quo: Imperial Authority. Imperial Authority is a measure of how successful the HRE is, beginning at 0 and ticking up to 100. It increases slowly based on the number of princes in the Empire and increases much more quickly when there is internal peace in the HRE. It’s given a boost when candidates from the same nation are elected in succession, adding yet another complication to potential war declarations. Once your authority reaches fifty, you can pass an imperial reform. These represent movements to centralise the HRE under leadership of a hereditary monarch and finally to unify it as one state. They must be unlocked in sequence and each give bonuses to the emperor (for instance, tax increases or additional diplomats) and in the early stages they benefit the member states, too. At about the halfway this becomes questionable as you slowly strip away the ability of states to declare internal HRE wars, subordinate them all as your vassals and unify them into one state under your rule. Scheming to increase authority is a delight since you can also increase it by expanding HRE possessions and reconquering areas which are governed at the start of the game by foreign kingdoms like Burgundy.
A unified Empire is not easy to achieve both because Imperial Authority is difficult to acquire and one catastrophe within the HRE is almost guaranteed to occur before you can unify it. In real life, this is the Thirty Years’ War (1618-1648) which wikipedia summarises as “one of the longest, most destructive periods in European history.” In EUIV, it has the potential to be much longer and much worse. The central issue is the Protestant Reformation. In 1444, predictably, every prince is Catholic. In EUIV, though, the Reformation is guaranteed to erupt in some Catholic nation and spread from there (though the year it begins and its centre are variable). It causes havoc in the Empire, which is suddenly split along religious lines as princes and provinces adopt new, Protestant doctrines. Every state not of the Emperor’s faith cripples IA growth and if the new faiths are widely adopted enough can even make it decrease. Protestants are ineligible to be the Emperor, but as soon as one elector is converted (a virtual certainty) religious leagues are automatically founded. The converted elector becomes the head of the Protestant League, who aim to remove the Catholic Emperor from office, make Protestantism the official faith in the Empire and Catholics ineligible for election. Provided you are still Emperor, Austria is made the head of the Catholic League, seeking to maintain Catholic dominance. As the members on either side increase, so too does the destructive potential for war, which is a certainty and can be tripped by any nation declaring war on the leader of either League. Moreover, nations outside the HRE can join either League. Historically (and often in the game) France, though Catholic, found itself joining the Protestant League for strategic reasons, and opportunistic enemies are sure to take advantage of the Empire in a state of religious war. At best these wars are a significant setback to your plans, at worst a devastating upheaval that could see you dethroned.
Simply maintaining your status as Emperor of the Holy Roman Empire is challenging. Unifying the Empire is extremely difficult, as it should be. Both demand a delicate balance of warring and diplomacy and strain the player’s ability to see the consequences of declaring war or allowing a principality to be swallowed. Controlling the HRE as Austria is strenuous at least until unification (which will take until the late game if you can do it at all). It’s rewarding, though, and playing as Austria is the richest, most interesting challenge EUIV offers.