This is the fourth in a series of reviews looking at the evolution of Europa Universalis IV. See the previous reviews here:
Europa Universalis IV: A Fantastic Point of View
Wealth of Nations: National Trade
Res Publica: A Tradition of the People

After Res Publica, a fairly small update and expansion, Paradox scheduled a larger expansion, and the biggest overhaul to EU IV yet. Art of War concentrated on warfare, with new events and mechanics for the Thirty Years War and the Napoleonic period. It was released with patch 1.8 on October 30, 2014, which included some massive overhauls of major mechanics in the game.

Patch 1.9 was a major patch with no accompanying expansion (this every-other major patch pattern became the general procedure for EU IV) that was released on December 19th, and did more re-works of the game. This review looks at both patches and the expansion.

Country Update

While different, the EU IV world map was naturally based on EU III’s, and was more detailed in Europe than anywhere else. Patch 1.8 increased the number of provinces by about half, and added a large number of new nations in all corners of the world. Some of these are only ‘potential’ countries; ones that can exist only by revolt or being released by a larger country, but many represent smaller nations that couldn’t be represented on the old map, or just better research on an area.

In addition, a number of new tradition sets were created, mostly for sets of these new countries, but overall the variety and individuality increased substantially. Finally, more dynamic historical events were added for all sorts of countries, enhancing that system overall.

Patch 1.9 then added the idea of disasters. There were a number of large-scale bad events that could affect a country, seemingly randomly. Now, they were surfaced to the user, making the game a bit more controllable, and feeding into the feel of this iteration being a game. Generally, all countries are eligible for the ‘peasant revolt’ (low manpower and stability) and ‘civil war’ (low legitimacy), while some countries have special ones (England can have the War of the Roses and the English Civil War disasters).

When the preconditions for a disaster are met, the clock starts ticking down to it. If the conditions go away, then the disaster stops, otherwise it fires once the clock ends. Peasant Wars have always been a more common one (especially for the AI), and as an example, force stability to -3, cause additional unrest, make stability more expensive, and creates a couple peasant armies for an immediate problem while the unrest and negative stability cause more.

This is one place where I feel too much is being surfaced to the user, as these are the types of events that, at best, are only obvious in retrospect. That said, getting stuck in a poor position, and watching the clock tick to an even bigger problem certainly does add its own brand of tension to the game.

Revolt & Unrest

Speaking of revolts, those changed too. The province-by-province check for revolts every month, that had existed since the original game was replaced by unrest. This is pretty much figured the exact same way, but it does not cause revolts in itself.

Instead, the province’s prominent revolt type is figured (independence, religious, pretender king, etc.), and all the provinces with a positive unrest towards that particular type add together for a chance of progressing a revolt. Then that is checked each month, and when it does come up, that revolt gets 10% progress, which is displayed in a few places. Once progress hits 100%, then an actual revolt happens with a decent army or two.

This makes revolts something of a ‘mini-disaster’, where you can see the problem coming from some time off. The listing of factions will even tell you, on average, how long it will take a revolt to occur based on current unrest and progress. If an in-progress revolt loses all support (i.e., the respective provinces go to negative unrest), it will lose 10% progress each month until it goes away, so solving a problem for a month or two will set it back, but not instantly get rid of it.

A final adjustment is that revolts that start on an island have been a very small problem as they can’t spread, and take control of more territory. Now a revolt that has control of everything it can reach will automatically try to move to a non-connected nearby province, without needing sea movement or anything, just a decent amount of time.

Autonomy and Clients

One of the things revolt risk did was cause lower taxes and recruiting, as the population was resisting the government’s efforts. This did not get taken over by unrest, and instead these factors are now reduced by autonomy.

Autonomy is a new measure of how much attention a province is paying to the central government expressed as a percentage; manpower and income from the province are both reduced by the amount of autonomy, which generally goes down a little each month while the country is at peace, and the later government forms tend to have bonuses to autonomy reduction.

Naturally, newly conquered territory will have fairly high autonomy to start with, though reconquering core areas and inheriting in a union will result in minimal, if any, autonomy. The big thing is that you can also raise or lower autonomy in an area, which will lower or raise unrest in the province. So, take a new province, raise autonomy, which reduces unrest, and then peace will eventually bring autonomy back down again. Or, lower autonomy to exploit a rich province, and garrison the area to put down any revolts that crop up.

Also, releasing independent nations has always been a way of splitting off troublesome areas, or creating a buffer. But, it requires an appropriate possible nation in the area, and that may include areas you don’t wish to let go of. With AoW active, custom client states become possible in the late game (emulating Napoleon’s many reorganizations of the map of Europe). They’re set to be fairly loyal, and get their own traditions, in addition to their territory and name being entirely at the whim of the creating nation (well, the territory has to be contiguous).

Wars of Reformation

The Reformation came in for its own major overhaul. Generally, events would fire to randomly convert provinces to Protestant or Reformed, causing chaos and potentially making conversion a smart idea for smaller central European states.

With the new patch, instead there would be centers of reformation that would actively try to convert other provinces nearby, going for more of a proselytizing model. This makes the entire process much less random, and ensures that anyone near one of these centers will have to deal with the problem for some time to come.

Generally, three centers show up for the Protestants, and then another three for Reformed (with the first of each as an event, and the other two being ‘rewards’ for the first countries to convert to the new religion). The process can be stopped, by conquering the province and converting it (which will destroy the center), but that’s not easy either.

AoW also introduced religious leagues. These are coalitions that form to enforce, or change, the religion of the Holy Roman Empire. To start with, the Emperor must be Catholic; but there’s no restrictions on the electors, and if one of them goes Protestant, then he automatically forms the Protestant League, which can declare war on the emperor to force the official religion of the HRE to change. Once started, anyone (regardless of religion) can join the leagues, but religious tension is what starts them.

Liberty, Equality, Fraternity

Along with the Thirty Years War, the French Revolution came in for some serious attention. The Revolution was of course one of the major points of events in the original two games, In III, there had been the separate Revolutionary Republic and Empire government types, which had event chains as pre-requisites for them, and some very powerful bonuses, along with plenty of events to make sure that such a government would end up at war with most of the rest of Europe.

Now, a Revolution disaster was added which could happen to any European country that was in dire straights in the late 18th Century, making them the revolutionary target (France gets a customized French Revolution disaster). The lead ‘unhappy’ country gets to be the target of the events that bring about the revolution, changing the government to Revolutionary Republic, and changing the national symbol to a tricolor (many countries have the colors defined, and the rest get random colors picked for them).

Of course, all the relations problems of the old system are kept here, with the Revolutionary government getting a casus belli to ‘spread the revolution’, while everyone else gets reactionary modifiers to put the anti-monarchist upstarts down.

Naval Affairs

Art of War had a few tweaks for the military, the biggest one being the ability to just upgrade ships to modern types with a single click. You still pay the standard construction cost, and the ships are reset to minimum morale and durability, but it’s instant, and saves all the trouble of retiring old ships to stay under your naval limit while building the new ones.

Even better (and really needed), the expansion allows the ability to mothball fleets. Generally, it was common to set naval maintenance to minimum during peacetime in previous EU games. This can save a fair amount of money, and you don’t generally need the morale while at peace. Except now, trade protection with light ships suffers with lower maintenance, so mercantile nations can’t afford to do that (and possibly still can’t afford a regular fleet). Mothballing basically sets maintenance to minimum for selected fleets, so your light ships can still do their thing (along with any anti-pirate patrols you end up needing), allowing big ship and galley navies to not strangle the economy any more.

A final option is the ability to sell surplus ships to other powers, though I’ll admit I haven’t played around with it, and don’t know how eager the AI is to take your old castoffs. Also, as part of the big map expansion, trade was reworked with a more stable pricing scheme, and three new trade items were added.

A final naval convenience is that transporting armies was made simpler in the expansion. If you give an army an order to march across a body of water, the game will now ask if you want to use your transports automatically. And then it will send them out, pick up your troops (automatically dividing the army if it’s bigger than the transport fleet), and ferry them over. It’s not perfect, as it’ll try to do this when the waters are contested, and you need to ‘sneak’ across away from patrolling enemy fleets, but it’s a big convenience when it can be used.


Just in terms of the patch, 1.8 was a great improvement for EU IV. The new Reformation mechanics feel a lot more natural, and let you see whether or not you’re likely to be in the path of religious controversy. The new revolt mechanics aren’t as dramatic, but affect you no matter when/where you play the game as, and was just the beginning of PDS re-thinking core mechanics that had been there from the beginning. EU IV changed a lot of things in the interests of a better game, and this showed that the process hadn’t stopped.

The new map of course added a lot of content. If you’re stuck in Western Europe, you won’t see the changes, but everywhere else saw some major changes, and loads of new nations (and potential nations), adding even more life away from the ‘bright center’ of the game’s roots. The amount of work to update the timeline files for all the extra provinces and counties must have been massive. As much as I say I’m not a fan of patch 1.9’s disasters, they are in line with the rest of the features of EU IV, and I can’t really complain.

The expansion is also big, with a lot of nice things in it, though the out-of-expansion changes are still big enough to get all the top billing. Much of it is paying for convenience, and despite the features, nothing is really essential. It certainly makes you happy to be able to just automatically ferry troops, or any of a half-dozen other things. Content-wise there’s also a lot in the events, but they’re hard to pick up on. So there’s no one ‘get this now’ feature, and I only recommend this to dedicated players.