Big things are happening on TV Tropes! New admins, new designs, fewer ads, mobile versions, beta testing opportunities, thematic discovery engine, fun trope tools and toys, and much more - Learn how to help here and discuss here.
Sadly, many reviewers and fans consider this to be a Dolled-Up Installment and The Scrappy of the series. The Expansion Pack made it much better. It was the first EU3-derived game to include detailed character mechanics, which led to (ultimately true) speculation that Paradox were working on Crusader Kings II. The general consensus is that Rome is a completely separate entity from the rest of the series, and there is a vocal minority in the fanbase that is pushing for a Rome II.
Europa Universalis IV (2013)
Conquest of Paradise, a colonial-focused expansion with the option for a randomized New World and Oceania, released in January 2014.
Wealth of Nations, a trade-focused expansion released in May 2014.
Res Publica, a republic-focused mini-expansion released in July 2014.
The Art of War, a military-focused expansion released in October 2014, also coming with a free patch that brings a far more detailed map for the non-European parts of the world.
Europa Universalis has you take control of a nation from roughly 1400 to the early 1800s. There are roughly 200 playable nations, although some are more playable than others. While not every nation is in the game, a good chunk of them are, and so apart from standbys like France or Britain you can try your hand at a world conquest as the Iroquois, the Duchy of Bavaria or the Sultanate of Makassar. OrSweden.The games have a history of buggy releases and somewhat impenetrable interface, with a variety of concepts not being adequately explained by game documentation (sometimes because they weren't in the original release version...), making the learning curve something of a learning cliff, and this is arguably the least complex of the Paradox Interactive strategy games.The games also have an impressive community of writers, whose dabbling in the artform known as After Action Reports is nothing to sneeze at. Some of their works are simple gameplay narrations, but others are intricate works of fan fiction indeed.Europa Universalis is closely linked to three other series of grand strategy games, all of them made by Paradox: Crusader Kings, Victoria: An Empire Under the Sun and Hearts of Iron. Theoretically, they can all be played in one big historically chronological succession thanks to a pretty brilliant (though somewhat buggy) Old Save Bonus system created by the developers, and the modding community will often create their own converters to fill in any gaps.
This game series provides examples of the following tropes :
Alternate History: A popular reason for loving the game series is because of the ability to "correct" things that went "wrong" in real history. A lot of it is really funny, especially when the player has had nothing to do with it. Some examples: Milan blobbed all over Europe, England eaten by Northumberland, Protestant Syria, the landlocked African nation of Sokoto winding up in control of Burma, and Ming China wandering around Egypt in the early 1400s. This has led to the concept of "hands-off games", where the player picks an out-of-the-way nation like Ceylon and disables popups, then leaves the game running for a few hours and comes back to see what hilarity has ensued.
There's a console command that lets you enter "Spectator Mode", which lets you do just that. The AI controls every country and reveals the whole map, leaving the player to sit back and watch "history" unfold.
"Henry IV of Lancaster led the 14000 strong French army against the 6000 strong Ottoman army, and their forces were triumphant."
Importing a saved game from Crusader Kings II adds another layer of Alternate History, as you play on a map that's been changing since 1066 or as early as 769. Sadly, it only effects Europe, the Middle East and India as Crusader Kings does not have a truly global map.
Alternate History Wank: Taking obscure one-province minors (such as Navarre, Trebizond or Xhosa) and turning them into major powers is literally a hobby for some experienced players.
Apathetic Citizens: Oh so averted. Your citizens are ANYTHING but apathetic and will revolt for a whole host of reasons. In the expansion to EU3 especially there are multiple kinds of rebels, who will do unpleasant things to you should you let them rampage (like converting your country to their preferred religion, change your government type, install a new monarch or declare independence)
One type of rebel that crops up a lot are the Particularists. One joke among players is that they're called that because they don't want anything in particular, they just like revolting.note Particularists are the game's "default" protestors - that is, when the revolt risk in a province is above zero but there are no other valid types of rebels such as patriots, revolutionaries, religious et cetera, the particularists will revolt in that province instead.
Arbitrary Headcount Limit: Averted; you can have an undefined number of soldiers and ships, with being actually able to pay and support them the only constraint. You can bankrupt yourself for all the game cares. There is however a soft limit based on your manpower, nation politics and traded goods that makes costs greater than normal if you go over it.
Artificial Stupidity: Generally averted, but the AI has its moments. For example, the AI tends to declare war with the Dishonorable Scum (If the player's Bad Boy score is too high) even when he's a one province country and the player controls half of Europe.
To be fair, this isn't so much stupidity as desperation to stop your country's inexorable advance. Countries that have burst their badboy/infamy limit have generally taken over a hell of a lot of land very quickly. It works too; even if a few countries fall a nation fighting the whole of Europe and a few nations outside it will find it will be overwhelmed eventually; the most said country can hope for is to knock out a few rivals quickly and then grimly hold the line.
The AI can't deal with naval attrition, and no one's been able to solve the problem. The workaround? They don't get any! This has led to a tendency for the Baltic to become a kind of Weirdness Magnet, with the Ottomans, Castille, various Italian and Low Countries minors, and whoever else feels like it grabbing bits and pieces of the Baltic coast and Scandinavia.
Not having attrition doesn't prevent them from screwing themselves on the sea, however. The AI occasionally sends out small fleets of just a few ships, even when they know the player's fleet is in the area. Sometimes this will happen so many times they'll have completely fed their fleet to yours piece by piece when they would have flattened you if all attacked at once.
As of the Divine Wind expansion, "Poland can into space" is an achievement acquired by reaching maximum level in all technologies as Poland. This one has carried on to EUIV, which has a Red and White rocket being fired into space as its icon.
"Spain is the Emperor" is achieved by becoming ruler of the Holy Roman Empire as Spain.
Some of Gotland's ships have weird names, in Swedish: Spain is not the Emperor, Comet Sighted, Sweden is OP, Big Blue Blob, Forum Troll etc.
Awesome but Impractical: The Napoleonic generals, including Boney himself, the absolutely best general in the game (6-6-6-3 in EU II) that can only be used for a few brief years.
Averted in EU III, where starting as the Ming in 1405 gives you Zheng He, an Explorer with 6 maneuver, who can be used to go off and discover America. Some players have had him last for something like 20 years.
Badass Boast: Many events have their choices worded as what the ruler would have likely said as they occur. That leads to a few quite badass, if sometimes misguided, boasts. For example, if high instability causes insubordination in one's army, the ruler can declare "Fine, I'll lead the army myself!" (while army tradition is being lost), or if you manage to draw the country back from the abyss of religious turmoil, proudly proclaim "ONE FAITH!" (as the country gains stability and loses revolt risk).
Balkanise Me: A prime strategy of the English against the French. France has dozens of releasable states making up over 75% of their territory. You can reduce France to the Ile-de-France and numerous minor countries over the course of two wars if you completely defeat them in both. Spain and England, along with several other nations, can also suffer this fate; England can lose Northumberland, Wales, Normandy (Calais) and Cornwall as sovereign nations. Castille only has to worry about Galicia, a single province state in their northwest, but once it becomes Spain it adds Granada, Aragon and Catalonia to the mix. Sweden has Finland to worry about, the Teutonic Order Gotland, the Ottomans various nations including just about the whole empire if they are unlucky enough to suffer a smashing after subduing the Byzantine Empire, and the Mongols and Timurids frequently collapse just trying to keep their various resurging nationals under control.
Challenge Gamer: These are the guys who do World Conquest with one-province minors. As of Divine Wind, the current challenge du jour is to do it with Ryukyu while remaining true to the Animist religion.
Cheese-Eating Surrender Monkeys: Up until the Heir to the Throne expansion, EU III was a serious candidate for the most triumphant aversion of this trope. France was dubbed by gamers as the "Big Blue Blob" for its tendency to conquer most of Europe. In the words of one poster: "France is the Final Boss of EU III."
Heir to the Throne played much closer to this trope, with a severely weakened France getting frequently eaten by Burgundy or by its minor vassals. Divine Wind seems to try for more of a middle ground.
Still a really big aversion since the Burgundians are French as well, and the Final Boss tends to end up either France or Burgundy (and sometimes Burgundy changes into France after taking all the French provinces).
As of the release of EU IV, the Big Blue Blob is back with a vengeance.
Chokepoint Geography: When appropriate. Terrain and the layout of provinces tends to channel armies into certain paths...
Can be used to great effect when instigated in another country.
The Computer Is a Cheating Bastard: depending on difficulty level at least. Some nations in EU III are also "lucky" and get extra bonuses (though this can be turned off).
Cosmetically Different Sides: All countries play by (basically) the same basic mechanics; the difference is mainly in the starting position, religion, tech group (which affects the speed of your research) and starting domestic sliders. Some of these can be changed (at least to some degree) while some are locked in place. In EU III all of these can be changed through normal gameplay. Not easily, mind.
This was slightly altered in the Divine Wind expansion, with Japan, China and the horde nations receiving unique gameplay changes to represent their unique historical political structure.
EU IV introduces a little differentiation through National Ideas: All of the countries you've heard of (and a lot you haven't!) have unique bonuses that can be gained through research. All of these bonuses do operate through the same universal game mechanics, though.
Crutch Character: Timur for the Timurids. He's a massively capable ruler and general...who is about to die of old age.
The Timurids as a whole, especially in AI hands. They're quite possibly the strongest military power in the world in 1399 besides Ming, but they tend to melt down fairly quickly once Timur dies (as happened historically), and aren't really equipped to face down the sheer number of enemies they have on their borders and the rebels that pop up whenever their leader dies.
A human can avert this fairly easily and turn the Timurids into a real powerhouse however. The trick is to make peace with everyone except the Indian empires and take the provinces necessary to form the Mughal Empire. This will remove all the penalties associated with hordes and leave the player with an extremely strong Military and Economy, although they won't tech as fast as the Western nations.
Curb-Stomp Battle: A well-blobbed player can steamroll over dozens of one-province countries with ease.
Cursed with Awesome: A border with any Horde state means they automatically declare war on you every five years. An inexperienced player would see this as a significant challenge (especially when considering the War Exhaustion mechanic and its tendency to cause massive revolts). An expert player sees this as a great opportunity to gain land, prestige, Imperial authority, or similar. A popular tactic is to acquire a border with Golden Horde as an HRE state (the easiest is Bradenburg/Prussia), and since winning a war as the Emperor gains authority, it's a surefire means of instituting the reforms needed to eventually unite the Empire.
Damage Is Fire: The siege screen displays a small picture of the city under siege. As the siege progresses one can see smoke and fire from within the city walls, reflecting its deteriorating condition.
Defeat Means Friendship: Forcing a country to become your vassal as part of a peace treaty immediately raises your relations to 200, the highest possible. Of course, since you've essentially conquered the country and are just letting the former rulers remain in power, this is a very Justified Trope.
The Dev Team Thinks of Everything: It's possible to play a game of Crusader Kings II and use the old save to start a game of EU4 where there's a nation that follows Zoroastrianism or a restored Roman Empire exists, neither of which are present in any of the starting points of normal EU4 games. And they have special stats and flags like any other religion or nation!
That is, the dev team of the converter thought of everything. EU4 itself does not have Zoroastrianism as a religion in the files, or a Roman Empire tag — but the converter already outputs the converted Crusader Kings II save as an Europa Universalis IV mod, so the converter simply has to add the Zorastrianism religion and/or the Roman Empire tag to the created mod. Zoroastrianism and the Roman Empire are just the big ones — there's even a contingency for the Jomsvikings (a company of staunchly Norse god-worshipping mercenaries) having land (complete with their own national ideas!).
The normal variant, which affects how certain mechanics work for you and the computer within the game.
Which country you pick, which changes certain aspects such as what government you start with, and what vassals and releasable states. This can change your luck much more than the normal variant, and allows certain Self-Imposed Challenges, like trying to restore the Byzantine Empire to how the Roman Empire was at its height.
Disc One Nuke: In Heir to the Throne and Divine Wind, it is possible for a Holy Roman Emperor to carry out a group of decisions that give them progressively more power in the Empire, eventually leading to abolishing the electorate, all members becoming vassals of the Emperor, and finally annexing the rest of the Empire into a single HRE state. The problem with this is, it's almost laughably easy to take a mega country- like say, France, or Poland-Lithuania- into the Emperorship. The end result? A nation state consisting of a completely cored mega-state and most of Germany and Northern Italy. The devs tried to curb this by making it so the HRE state only gains cores on nations that directly border it- thus making the first 50 years a rather hectic period of running around playing whack-a-mole with rebels- but after 50 years, it gives you the undisputed most powerful nation in the world, with a manpower only rivaled by Ming China.
Early Game Hell: You can try to revive the glory of the Byzantine Empire - starting just a few decades before it was invaded in real life. You have only a few provinces (with ocean and enemy territory between your capital and them), an all but nonexistent army and navy, are surrounded completely by a much stronger enemy who wants your capital province and will work to claim it, and your only ace is that your capital province is a trade center, which really doesn't do you much good all things considered. There are nearby powers you can form alliances with, they tend not to do much if any good unless the Ottomans find themselves in a bad position early on, which rarely happens. Recommended strategies tend to be "gamey", like exploiting the peace treaty and vassalage systems to gobble up territory in eastern Europe before the Ottomans can. Luckily the game does give the player considerable bonuses just for being able to expand into the Byzantine Empire's old territory, but most games played as Byzantium won't even make it to that point. The Muslim equivalent to the Byzantine Empire is Granada, with Castile (most likely Spain later), usually in conjunction with Portugal and Aragon, filling the role of the Ottoman Empire. IV even offers players who manage to pull off conquering all of Spain and Portugal as Granada the Re-Reconquista achievement.
Easily Conquered World: Considering that total world conquest is possible, this is definitely true. This is sometimes known as "blobbing".
Subverted in the Magna Mundi mod, where there are several blockers in place to limit unrealistic blobbing, and aggressive expansion is not always the most efficient use of your time and money.
Easy Communication: The player gets notified about stuff happening a world away (cardinals dying, peace treaties being signed, rebellions erupting, etc.) the second they happen. The world-exploring mechanics subvert this, however, as it takes between 25 and 50 years for another nation's discovery to spread to the rest of the nations.
Easy Logistics: Played with; while the abstraction level is too high to bother with boots and blankets, your armies DO have to be paid, and simply leaving them around means they will suffer "attrition", slowly (or, if you are, say, in Russia in winter, VERY QUICKLY) reducing their strength. Just like in Real Life, though there are no supply lines; Armies have to live off the land where they are stationed.
Event Flag: There are a wide variety of events in the game; some are random, most have some kind of trigger. In the earlier games some were "Historical" and would trigger for certain countries in order to recreate certain historical events, such as the Habsburg inheritance of Hungary. These were removed in EU III (though restored in some of the Game Mods, with more complex trigger conditions to ensure that historical events only happen when the conditions are appropriate); whether that is a good thing or not is a matter for debate.
The fourth game tries to balance the pros and cons of this system by introducing special historical event chains for certain nations. For example, every nation can descend into civil war if a king dies without heir, but if the same happens in England at a certain time frame the game will trigger a War Of The Roses event chain. Similarly, if Russia did not westernize after a certain date but is ruled by a competent king, an event chain might trigger that simulates the modernization reforms enacted by Peter the Great. A low stability level generally enables bad things to happen, but in a certain time period in Russia it can trigger the Time of Troubles event chain. And so on.
Expy: In the third and especially fourth games, certain advisers can become this particular timeline's equivalent of a famous person from history (a la In Spite of a Nail). For instance, if you have a particularly skilled Astronomer around the latter few decades of the 15th century, he might end up replicating the accomplishments of Tycho Brahe.
Patriotic rebels who want to join an already existing nation which has their culture as the primary culture.
Nationalist rebels, who want to form an entirely new nation from the provinces where they are the majority culture, which can be quite significant in newly conquered nations.
Final Boss: As noted above, especially powerful AI nations (France in particular) often end up taking this role.
If you are focusing on Europe, watch out for the Ottomans, Poland-Lithuania, Russia (with their infinite manpower), and Austria (who, true to form, marry anything with a pulse and inherit later). If you are colonising, beware of Castile, Portugal and England (if they weren't eaten by the Wars of the Roses or the French). Always beware of France.
If you're playing Europa Universalis IV and are importing a Save from a Crusader Kings II game with the Sunset Invasion DLC enabled, the Aztecs and Inca are going to be some of your hardest foes due to their equal tech group, their ideas which tend to lead to the Natives invading Europe first, quite often an outright *lead* in technology, and huge swathes of territory they already have and plenty more they can just gobble up without much opposition. You can forget about trying to conquer them with a few hundred men.
Fog of War: the standard version, and also the fact that "unexplored territory" can only be removed by armies or navies led by conquistadors and explorers respectively. Some parts are also "Permanent Terra Incognita" (such as the interior of Australia, Africa and the Americas) and cannot be explored at all.
On the Strange Screenshots thread in the forums, there's a picture of a nameless Lithuanian general with ridiculous stats. Normally the maximum stats for a general are 6 shock / 6 fire / 6 maneuver / 4 siege, but this guy had 300,000 shock / 0 fire / over a million maneuver / and 0 siege. There were Chuck Norris jokes. Possibly the result of an overflow error.
In the Divine Wind expansion, an event was created that requests nations hand over imperial land to the nation in control of the Holy Roman Empire. It was intended that the human player release these lands as sovereign states, as doing so would increase the Emperor's influence and not doing so would lead to infamy gains, which has very negative effects. However, the AI never releases land as sovereign states of its own free will. The result is that the emperors become the most hated nations in the world, and the Holy Roman Empire practically collapses as many imperial nations go to war with their emperor.
The 5.1 patch fixed this bug. Prior to the fix, the player could get quite savagely mauled by it due to certain provinces being unreleasable for cultural-mismatch reasons.
Geo Effects: Rivers, hills and mountains give juicy bonuses to the defender and sensible commanders take advantage of this fact to exploit Chokepoint Geography.
Hegemonic Empire: As typical of Paradox Interactive games, there are mechanics for expanding through peaceful vassalization and annexation. Austria has missions to encourage this, and can in its initial place form a much larger empire diplomatically, with some diplomatic cunning and strength.
Hired Guns: Mercenaries. They deploy faster but are much more expensive to supply.
This can also lead to Richard Nixon the Used Car Salesman, especially since the game randomly selects first and last names for advisors and mercantile/religious leaders from the appropriate languages. Though in IV there are events to grant access famous advisors, like Da Vinci and Machiavelli, to the proper nations if the conditions are right.
Holy Roman Empire: The HRE features as an actual game mechanic where nations are voted to lead it upon death of the present leader, and with Imperial Authority can enact reforms upon the Empire. With enough reforms, the leader can make the other members their vassals, and make the Holy Roman Empire one unified country, with the head of it being the leader of the new nation (this also disables the special HRE mechanics, just as if someone abolished the Empire). Sections of land away from the main part of the empire are labelled as 'Imperial', such as 'Imperial Asia'.
The Horde: Divine Wind turns all of Central Asia over to these guys, with the particularly nasty twist that they automatically go to war with every neighbor every five years. The Golden Horde and Timurids are strong enough to be Demonic Spiders, while the minor hordes (Nogai, Qara Koyunlu, Kazakh, Chagatai, Oirats) are more like a Goldfish Poop Gang.
Incest Is Relative: Marrying off your teenaged daughter to your cousin twice removed who rules a neighboring country is an excellent way to improve the relations with said country. (As well as an excellent way of creating REALLY weird family trees.) You can in fact arrange Royal Marriages with every nation ruled by a noble house that shares your religious group.
EU3 doesn't bother with family tree mechanics, so there's a surprising amount of Regency Councils since heirs die like flies. On the other hand, sometimes you have a king crowned at 16 and a 10-year-old heir, and since it's not explicitly stated what relation the heir is to the king (and people assume it's his kid), you get people thinking that rulers often have children when they're 5 or 6.
The Heir to the Throne expansion removes this in favour of "wasteland", which is basically the same thing but visible. Note that most of the American West is "wasteland". Which for the purposes of the game it is - it wasn't explored nor settled (by Europeans, anyway) until after the end.
Italian Wars: The in-game mission mechanics encourage this, with European countries occasionally getting a "Get a foothold in Italy" or "Keep Austria out of Italy" mission.
Kill It with Ice: Attrition is higher during winter in frozen provinces, and this combined with a scorched-earth strategy can deeply decimate a superior enemy army. The Real Life campaigns in Russia can thus be simulated.
Land of One City: Commonly called One Province Minors, or OPMs (strictly speaking, all OPMs aren't actually lands of one cities — many provinces are large enough to in reality have several cities in them, but all one-city lands are one-province minors, and in game terms one province=one city).
Magikarp Power: Germany starts out divided into dozens and dozens of mostly one province little countries. Conquer the right ones and you can gain the option to form Germany which can quickly become one of the most powerful countries in the game. Do this early in the game before Spain, France, Russia, and Great Britain have formed and you easily have THE most powerful country in the game.
The Timurids (once Timur himself dies) are prone to rebellions and other woes even by horde standards. Sucessfully reform the government into a proper kingdom, however (or better yet, form the Mughal Empire), and you've got a powerful nation with mountainous terrain that can be a nightmare to invade, access to multiple high-value trade zones,and lots of potential for colonization, with Africa and some Paciific islands close by.
Generally, any large nation in Asia or Africa if you westernize soon enough.
Mission from God: Three examples: The Holy War casus belli, the Deus Vult national idea and the mission mechanic flavor text: "God's will has been revealed to us!"
Moral Myopia: In the third installment, there is no stability hit for declaring war on a heathen nation outside one's religious group without a casus belli. Countries can also take a National Decision that extends this to heretic nations within the same group as well.
After a patch, this is replaced by a Holy War Casus Belli on heathens (either neighbors or just all heathens, depending on your national decisions and government), which expires in the midgame. In Europa Universalis IV the expiration date was eventually removed.
The Musical: As an April Fools' joke in the leadup to EU IV, Paradox announced Europa Universalis: The Musical, and even released three songs from it: "Casus Belli," "Prestige," and "Empire Borders".
Names to Run Away From Really Fast: Pirate ships in IV mostly have names in various flavors of evil, from the simple yet intimidating ("Executioner", "Death", "The Nightmare") to the more elaborate and at least as intimidating ("The Fear of the Demon", "The Doom of the Ocean", "Killer's Fearful Storm").
IV takes this a step further with its official converter from Crusader Kings II, keeping the exact countries and rulers (and, if reformed, pagan religions). With the earliest start date in 867, that's 900 years total gameplay just between those two.
Notably, importing a game from Crusader Kings II with the Sunset Invasion DLC installed will lead to a very different New World. Rather than the pushover Empires of the normal game, the nations you meet are much more powerful (especially the Aztecs and Inca) who rather than having the Vanilla American tech group (the worst in the game), now have the High American tech group (equivalent to the Western, or best one in the game). In keeping with the Native Americans inventing gunpowder infantry in the Sunset invasion DLC's timeline. Their old ideas are replaced with a set that encourages them to invade Europe and finish what they started in CKII. Needless to say, this turns what used to be easy conquests into the fight of your life and serves as a rather rude awakening for someone used to the standard Americas.
Other bonuses from Crusader Kings II include the Jomsviking holy order who form if they still have land by the time they're exported, who like the Natives above, have their own unique ideas, and the reformed Roman Empire which once again, has it's own set of unique national ideas generally oriented towards making running the Empire easier. Time will tell how the custom Kingdoms in the new upcoming Crusader Kings DLC will be handled.
One Stat to Rule Them All: In EU4, Prestige and Legitimacy improve the morale of your armies and give other bonuses. Having low Legitmacy and low and negative Prestige will make it very difficult to win wars without significant numerical superiority.
The Pope: The Papal State is playable. Some installments have a separate Papal Controller mechanic that gives the player who controls the College of Cardinals access to special benefits and decisions.
Pretext for War: The entire purpose of the casus belli mechanic. If you declare war without a legitimate reason, expect to take some severe consequences.
Reality Is Unrealistic: Some real historical situations will almost never happen in-game. For example, usually the first step for a European power colonizing North America would be to conquer and annex the native tribes (such as Creek), while in real life they survived well into the 18th century.
The unification of larger nation-states is something the AI & game mechanics prevent from happening historically. Russia and Spain, particularly, will almost never form at the appropriate time. Sometimes the effect is reversed - Great Britain tends to form centuries early, primarily because England already has most of the conditions to form it, and all it needs is to take over two provinces in Scotland and hold them until they become cores.
Divine Wind has made it so Britain at least forms close to when it is supposed to because it gets a mission to conquer Scotland at around that time. Brandenburg-Prussia has a tendency to never form unless a human plays Brandenburg (the Duchy of Prussia forms often since all that needs to happen is for the Teutonic Order to survive until the Reformation, but Brandenburg often fails its missions to conquer the Prussian lands or doesn't become Protestant, which is required to form the Kingdom of Prussia). It is at any rate virtually impossible for the Kingdom of Prussia to form historically (ie Brandenburg inheriting Prussia through a personal union).
Most such events are technically possible, just highly unlikely during normal gameplay and often not very good strategy.
Rearing Horse: The cover of Napoleon's Ambition resembles the iconic painting of his crossing of the Alps. Similar images are used for the loading screens.
Ridiculously Fast Construction: Averted; buildings take a year or more to be completed and soldiers need some months to be recruited, and more than usual if there's internal dissent in your provinces.
Royal Mess: In the third game, any independent monarchy which does not use the Imperial form of government has its ruler termed King/Queen, even if historically many of those were not kingdoms (like All the Little Germanies, for example). A few mods more or less rectify this, by making the ruler title dependent on both the government type and country size.
Running Gag: Revolving around a But Thou Must situation. In the original EU III, the event meteor sighted had only one option, which...caused your country to become less stable. The fans clamored for more options (as most events have multiple options), so Paradox added a second option...which had the exact same effect. Heir to the Throne added a third option (same effect) and Divine Wind, the latest expansion, a fourth.
Played Up to Eleven in quite a few mods, which add ridiculous amounts of choices, of course all with the same outcome. The ones down the list often carry headers like "Oh, not again", "Will this ever stop?" and so on.
The gag has carried on to EU III's sister game Victoria II, where the Comet Sighted event causes scientific progress (Victoria is set in the XIXth century)...and the text of the option is "Thank God we live in such enlightened times". In EU IV, the last option says essentially: "I wish we lived in more enlightened times," in a throwback to Victoria. The event "The Curse of Tutankhamen" similarly refers back to EU III's infamous comet.
The same gag has carried over into EUIV, but this time it's noted as a comet with only one option, which is "It's an omen!", which causes you to lose one stability.
The 1.4 patch added an additional option to the event, "The End is Nigh!", which, you guessed it, has the exact same effect.
The 1.6 patch does it again with "The Economy, Fools!".
The 1.8 patch adds another with "I wish we lived in more enlightened times".
Salt the Earth: The ruler can enact a scorched-earth policy to hinder the supplies of enemy armies and increase their attrition. The action puts a dent in the involved province(s) economy.
Self-Imposed Challenge: Trying to play as a one-province minor (OPM) that is next to a larger neighbour, such as Bar, which is sandwiched between Burgundy and frequently its first call for conquest, or any of the Irish minors. A popular project is to try to take one of these minor states which are generally swallowed up in the first decade or so of gameplay and turn them into world-conquering empires!
Settling the Frontier: The colonization gameplay mechanics. The game really stresses that colonies are always built with a lot of hit-and-miss effort and over a number of years and decades. Notably, even if your colony reaches enough of a population to be considered a new province of your country, it only becomes a fully integrated province after 20-50 years.
Shout-Out: The cheat in EU II for "always win battles" is DIFrules! DIF is one of hockey teams in Stockholm, where Paradox Interactive is located.
Said cheat also changes your country's flag to that of the DIF hockey team.
In EU III, once Aragón learns about said province, it can get the mission "Become King of Gonder". Yeah, notice what they did there... Heir to the Throne expanded on the theme with the addition of the Turkish Beylik of Saruhan... and their flag featuring a white hand. (Needless to say, Aragon now can get "Defeat Saruhan" as a mission, too). These 2 missions made a return in EU IV.
If you have Plutocracy idea group in EU IV, there is one event that is basically a reference to Braveheart.
A flavour event that triggers when Paris becomes Swedish culture references the forum Something Awful, which several developers frequent and Johan has described as "the best forum I'm not an administrator of".
The Hashashin (if you imported them from CK 2)'s first national idea is something about a Creed.
In EU4, Venice can get a mission to expand into mainland Italy. Where? In fair Verona, where we lay our scene. (There's a high probability that you won't get this mission due to the fact that at 1444 start Venice already owns Verona.)
In EU4, it's possible to get an event that decreases unjustified demands called Justify my War, with the text "For you, to justify my..."
In EU4, when you are the Holy Roman Emperor, and you win a war in defence of the empire, a possible acceptance option of the announcement that you've earned Imperial Authority from coming to the rescue is "I have foreseen it!"
Staged Populist Uprising: In the third game, you can use spies to incite rebellions within your neighbors' borders, although the people there usually have to have a good reason to rise up in the first place. Unlike rebels that spawn naturally, the resulting mob will not be hostile to your own troops.
Succession Crisis: Things can get messy when a monarch dies heirless, their heir has low Legitimacy, or they rule a tribal nation.
Tribal Succession Crises are an absolute nightmare in III - you will, obviously, be doing a lot of conquering as a tribal horde, but cores take fifty years to form - and a rebel stack spawns in every non-core province, plus a massive pretender rebellion in a random cored province. The end result? Easily in excess of a hundred thousand rebels. And this happens every time the king dies! Obviously, the preferred Timurid strategy is to race to India and form the Mughal Empire before Tamerlane dies.
Super Not-Drowning Skills: One common way of getting rid of a monarch with bad stats is to make him a general, give him command of a single regiment, load the regiment onto a transport and sail out into the middle of the ocean. The transport will sink with all the soldiers, but the monarch somehow manages to swim several hundred miles back to shore and pester the nation anew.
The Byzantine Empire is the classic example in the games where it shows up. Trying to restore it to its former glory is a popular pastime for skilled and ambitious players.
Another Self-Imposed Challenge is trying to keep the hopelessly declining Timurid Empire and Golden Horde from disintegrating; in particular, a Timurid Empire that morphs into the Mughal Empire with most of its territory intact is truly a force to be reckoned with.
Depending on how late you start the game, the Spanish and Ottomans also apply.
If the Holy Roman Empire is united by the AI, it tends to become this within a few decades.
The game's mechanics for colonization sometimes encourage genocide as a means of stopping native attacks on your settlements if they are overly-aggressive. However if they are peaceful it pays best to tolerate them since they'll join your colony once it reaches city levels, giving you more population and benefits.
Believe it or not, the Magna MundiGame Mod for EU III actually inverts this. The computer gets its revenge...
Video Game Geography: While probably A LOT better than most games, Moscow in EU2 famously was located in a very wrong place.
The Heir to the Throne expansion pack for EU III changes the previous "permanent terra incognita" zone to visible, but unexplorable provinces. All described as "wasteland" - wasteland such as the Brazilian rainforest or the jungles of Africa.
Granted, "wasteland" doesn't refer to the lack of vegetation, but to its suitability for colonization (by white Europeans). The rainforests were almost impenetrable until we started developing cures for diseases like malaria, and the American West was known as "the Great Desert" before it started being extensively irrigated.
Most notably, in Divine Wind Japan is divided up into warring clans, as it was historically. However, at start, it's divided up as it was in 1180, at the start of the Genpei War. The game begins in 1399.
War for Fun and Profit: Some Casus Belli encourage the player to demand money instead of lands, as part of the peace treaty.
What the Hell, Player?: The reputation ("badboy" or "infamy") mechanic is supposed to be this. Aggressive acts (annexing nations, declaring wars without casus belli, taking territories that you don't have cores on) add badboy points to your reputation score. If you keep your aggression in moderation, your score will eventually go down with time; however, if you go on a conquering binge, don't be surprised if all your neighbors suddenly decide to gang up on you all at once.
In IV, the mechanic was replaced by the Aggressive Expansion penalty gained by demanding provinces at peace talks, annexing personal union partners or vassals, or vassalizing countries. Instead of being a global score that warrants war from anyone, it is a relation penalty applied to your immediate neighborhood that, if too large, gives said neighborhood a propensity to form a coalition (a pact in which if one member declares war on you, all others do) against you.
Won the War, Lost the Peace: If you're not careful, you can fight a war to a victory only to find that your country has descended into a rebel-haunted death spiral, and the new annexations prove to be nothing more than another spawning ground.