History YMMV / EuropaUniversalis

** Also, the [[ButThouMust Meteor Sighted]] event.

** The debate of historical accuracy vs gameplay balance. One of the more extreme case is the decision to move the Vietnamese culture to the Chinese group, which has never been the case previously in ''[=EU=]'', in order to enable an alternative history scenario in which Vietnam somehow conquers China proper, despite the fact that this ''weakens'' Dai Viet's resistance from Ming invasion which is the ''real'' history scenario.

*** The biggest and most divisive issue for ''IV'' was probably introduction of colonial nations. The moment a player colonises (or otherwise have cores in) five provinces in arbitrary decided regions in the Americas, and Australia[=/=]New Zealand, a colonial nation is automatically formed from the colonies and from then on works as a vassal, while each new colony in that particular region will be automatically handled over to the [=CNs=]. This is all done with ''[[ScrappyMechanic absolutely zero control on the player side]]''. For some players, it is enough reason to ''not colonise at all'' (unless you're colonising the Old World), treating them as money sinks with zero monetary gain, while others love the fact that [=CNs=] build large armies which the mother country doesn't have to pay for and then provide them expeditionary forces whenever asked. Bringing up this issue on the official Paradox forum is an almost guaranteed way to start an all-out brawl.

%%** ''Leviathan'' and its 1.31 update were outright nigh-unplayable at launch [[ObviousBeta due to the sheer quantity of glitches]] affecting even parts of the game that weren't modified by 1.31 and some dangerous enough to [[GameBreakingBug stop a campaign entirely due to repeated crashes]] or even ''[[UpToEleven wiping out its savefile]]'', giving the impression that despite being one year in the making, QA was essentially nonexistent. The content of the DLC itself was lambasted for being badly unbalanced [[note]]Among some of the worst offenders, the Alhambra monument gave 15% admin efficiency at launch for a mere 2000 ducats, the pyramids of Gizah gave -15% technology cost to pagan nations, conventrate developement/pillage capital allowed you to easily build a megacity of 60 dev and more by 1500, and tribal developement was given too generously, causing the whole of North America and Australia to be covered in ludicrously well-developed provinces rivalling Rome or Beijing, some reaching to up to ''80 developement'' in just a few decades.[[/note]], unfocused [[note]]Despite starting as a South-East Asia rework, it ended up making changes in Australia, Oceania and North America as well, as well as some worldwide features such as monuments.[[/note]], and sometimes outright unfinished[[note]]Many Polynesian missions had generic art, or even sometimes no art at all, Sikhism had noting but obvious placeholder art for its bonuses, and Zoroastrianism could not hide its origin as revamped Coptic Christianity[[/note]]. All that caused a massive InternetBackdraft against Paradox and the DLC, with the user review of ''Leviathan'' reaching as low as '''9%''' and becoming ''the worst-reviewed product on Steam.''

%%* SeasonalRot: It is generally admitted among the community that updates and accompanying [=DLCs=] started declining in quality later in ''EUIV'''s lifecycle. Depending on who you ask, the rot set in early to late 2018. The reasons for this are multiple: first of all, updates became increasingly unbalanced, with nations recieving [[PowerCreep massive buffs]], exacerbed by [[ArtificialStupidity the AI rarely being capable of exploiting these buffs]]. Second, while Paradox was never stranger to unstable launches, some updates went as far as being an ObviousBeta, plagued by crashes and bugs. Third, the update rate slowed to a crawl starting from 2019, with a single major patch in 2019 and another in 2020, while 2018 and prior had at least four each.

%%** ''Leviathan'' and its 1.31 update were outright nigh-unplayable at launch [[ObviousBeta due to the sheer quantity of glitches]] affecting even parts of the game that weren't modified by 1.31 and some dangerous enough to [[GameBreakingBug stop a campaign entirely due to repeated crashes]] or even ''[[UpToEleven wiping out its savefile]]'', giving the impression that despite being one year in the making, QA was essentially nonexistent. The content of the DLC itself was lambasted for being badly unbalanced [[note]]Among some of the worst offenders, the Alhambra monument gave 15% admin efficiency at launch for a mere 2000 ducats, the pyramids of Gizah gave -15% technology cost to pagan nations, conventrate developement/pillage capital allowed you to easily build a megacity of 60 dev and more by 1500, and tribal developement was given too generously, causing the whole of North America and Australia to be covered in ludicrously well-developed provinces, some reaching to up to ''80 developement'' in just a few decades.[[/note]], unfocused [[note]]Despite starting as a South-East Asia rework, it ended up making changes in Australia, Oceania and North America as well, as well as some worldwide features such as monuments.[[/note]], and sometimes outright unfinished[[note]]Many polynesian missions had generic art, or even sometimes no art at all, and sikhism had noting but obvious placeholder art for its bonuses[[/note]]. All that caused a massive InternetBackdraft against Paradox and the DLC, with the user review of ''Leviathan'' reaching as low as '''9%''' and becoming ''the worst-reviewed product on Steam.''

* ObviousBeta: ''EUIV'''s ''Leviathan'' DLC in 2021 received widespread negative response due to unfinished UI[[note]]for the Sikh religion panel, the "final" art looks exactly like the placeholder art previously shown in a Developer Diary[[/note]], missing tooltips, off-the-scale numeral errors[[note]]Commander-turned-monarchs with hundred in mana skill point, and various "divide by zero" errors that happen due to the formulas for development cost and governing limit[[/note]], frequent crashing on top of the usual balancing and AI issues accompanying any expansion with containing overhauls, making the new version not merely unfun to play but ''unplayable''.

* ObviousBeta: The ''EU4'''s ''Leviathan'' DLC in 2021 received widespread negative response due to unfinished UI[[note]]for the Sikh religion panel, the "final" art looks exactly like the placeholder art previously shown in a Developer Diary[[/note]], missing tooltips, off-the-scale numeral errors[[note]]Commander-turned-monarchs with hundred in mana skill point, and various "divide by zero" errors that happen due to the formulas for development cost and governing limit[[/note]], frequent crashing on top of the usual balancing and AI issues accompanying any expansion with containing overhauls, making the new version not merely unfun to play but ''unplayable''.

* ObviousBeta: New patches often have some things that can be exploited or minor bugs, but some have stood out as almost completely broken.
** The release of 1.30 (Imperator) was an unmitigated disaster. Every single new mechanic was so fundamentally bugged it should have been obvious to any QA tester within a single run as any European country. Nations would join the HRE at the drop of a hat, leading to everyone from Byzantium to Novgorod to Brittany creating a bloc impervious to outside expansion by 1450. Imperial incidents were broken, with the Shadow Kingdom event leading to Italian nations leaving the HRE and then rejoining the next day. The Council of Trent frequently simply did not fire at all, when it was a major mechanic in the new patch. Mercenary regiments could be split by loading some of them on to transports to recreate the old mercenary system. New events (like estate statutory rights) would pop up every day if they could, completely breaking players games. Most of these were fixed fairly quickly, but it was an astonishingly poorly tested product that had itself been developed over ''an entire year'' to give the team more time to implement and test good features. Instead, it created an impression no testing at all was made, with predictable reception.
** Release 1.31 (Leviathan) was no better. Just to name a few: horde ideas giving a bonus that gave ''+100% conversion speed'' [[note]] as in, provinces are converted in ''one month''[[/note]], North American natives constantly joining and leaving federations, extremely unbalanced buffs from monuments, crashes when hovering over some native Australian government reforms, one naval battery disabling piracy in the whole world, going over government capacity as a stateless society giving a bonus rather than a malus, broken announcements, placeholder art still being present for the sikh religion and, perhaps most egregiously of all Majapahit, ''which is the name of the free release'', being completely unplayable without the DLC due to having no way of preventing the "Collapse of Majapahit" disaster that will without fail kill you.

* ObviousBeta: New patches often have some things that can be exploited or minor bugs, but the release of 1.30 (Imperator) was an unmitigated disaster. Every single new mechanic was so fundamentally bugged it should have been obvious to any QA tester within a single run as any European country. Nations would join the HRE at the drop of a hat, leading to everyone from Byzantium to Novgorod to Brittany creating a bloc impervious to outside expansion by 1450. Imperial incidents were broken, with the Shadow Kingdom event leading to Italian nations leaving the HRE and then rejoining the next day. The Council of Trent frequently simply did not fire at all, when it was a major mechanic in the new patch. Mercenary regiments could be split by loading some of them on to transports to recreate the old mercenary system. New events (like estate statutory rights) would pop up every day if they could, completely breaking players games. Most of these were fixed fairly quickly, but it was an astonishingly poorly tested product that had itself been developed over ''an entire year'' to give the team more time to implement and test good features. Instead, it created an impression no testing at all was made, with predictable reception.

* ObviousBeta: New patches often have some things that can be exploited or minor bugs, but the release of 1.30 (Imperator) was an unmitigated disaster. Every single mechanic was so fundamentally bugged it should have been obvious to any QA tester within a single run as any European country. Nations would join the HRE at the drop of a hat, leading to everyone from byzantium to novgorod to Brittany creating a bloc impervious to outside expansion by 1450. Imperial incidents were broken, with the shadow kingdom leading to Italian nations leaving the HRE and then rejoining the next day. The council of Trent frequently simply did not fire at all, when it was a major mechanic in the new patch. Mercenary regiments could be split by loading some of them on to transports to recreate the old mercenary system. New events (like estate statutory rights) would pop up every day if they could, completely breaking players games. Most of these were fixe fairly quickly, but it was an astonishingly poorly tested product that had itself been developed over an entire year to give the team more time to implement and test good features.

* ObviousBeta: New patches often have some things that can be exploited or minor bugs, but the release of 1.30 (Imperator) was an unmitigated disaster. Every single mechanic was so fundamentally bugged it would have been obvious within a single run. Nations would join the HRE at the drop of a hat, leading to everyone from byzantium to novgorod to Brittany creating a bloc impervious to outside expansion by 1450. Imperial incidents were broken, with the shadow kingdom leading to Italian nations leaving the HRE and then rejoining the next day. The council of Trent frequently simply did not fire at all, when it was a major mechanic in the new patch. Mercenary regiments could be split by loading some of them on to transports to recreate the old mercenary system. New events (like estate statutory rights) would pop up every day if they could, completely breaking players games. Most of these were fixe fairly quickly, but it was an astonishingly poorly tested product that had itself been developed over an entire year to give the team more time to implement and test good features.

** Go on and try playing ''IV'' without picking Trade ideas. It's even less of a no-brainer choice, given its necessity. Short of playing a country that has default bonuses to trade and number of merchants, it will be flat-out impossible to participate with the entire trade part of the game, and if you have innate bonuses to trade, your best course of action is to strengthen them with that set of ideas.

* GuideDangIt: For ''IV'', when building Manufactories, the interface only informs the player of the direct boost to income. The indirect boost through increase in the province's trade value (as more goods are produced) is not mentioned - ''despite being the main reason to build then''.

*** And if you are any of the nations from around the Danish Straits, good luck collecting in Lübeck, because English, Dutch and French ships are going to do their very best to steer that trade to neighbouring English Channel node. Inflow from the colonies? Good luck competing over England[=/=]Great Britain over the North Sea, so they ''will'' send that trade to English Channel. Short of conquering or vassalising Scotland and[=/=]or Ireland, it's nigh impossible to send colonial trade toward Lübeck.

** Ironically, 6/6/6 heirs or rulers are also considered as such,[[ViolationOfCommonSense as they usually end up dying more often or]] [[TooAwesomeToLive earlier than lower skilled heirs and rulers.]]

* MemeticLoser: Enrique (Castilian for Henry), the atrocious 0/0/0 heir to the Castillian throne in 1444 has gained this status. TruthInTelevision, as his historical counterpart, [[https://en.m.wikipedia.org/wiki/Henry_IV_of_Castile Henry IV of Castile]], was nicknamed ''the Impotent''.

*** ''Eat your Greens'' requires you to play as the tiny nation of Kale and conquer all grasslands in Asia... before absolutism. There are generally two paths to this achievement, one that involves blocking global trade from ever spawning to stall the age of absolutism (which isn't easy on itself), while the official way is a race against time to conquer the immense amount of lands all over the continent before 1610. Doing so you will have to fight almost all major powers in Asia, including Ming, in a relentless race against time sometimes said to be even harder than the aforementionned ''True Heir of Timur''. And unlike the Mughals, Kale merely sports mediocre ideas and a generic mission tree.

*** ''Eat your Greens'' requires you to play as the tiny nation of Kale and conquer all grasslands in Asia... before absolutism. There are generally two paths to this achievement, one that involves blocking global trade from ever spawning to stall the age of absolutism (which isn't easy on itself), either a race against time to conquer the immense amount of lands all over the continent before 1610. While doing so you will have to fight almost all major powers in Asia, including Ming, in a relentless race against time sometimes said to be even harder than the aforementionned ''True Heir of Timur''. And unlike the Mughals, Kale merely sports mediocre ideas and a generic mission tree.

* UnderusedGameMechanic: It could be argued that ''IV'' is ''build'' from those. The general consensus among players is that due to the design philosophy of [=DLCs=] being self-contained and non-interacting with each other, any mechanic that exists within a DLC is by default shallow and doesn't carry much weight in actual gameplay. Examples include things like innovativeness[[note]]A scaling modifier in regards on how advanced technologically a nation is, gained by rushing technology or adopting an idea first (this one gets exhausted within first 50 years of the game) and utterly meaningless unless reaching 100% value[[/note]], army professionalism[[note]]Another scaling modifier that gives small bonus to dealt damage on national scale and unlocks such stunning abilities like reinforcing a fort instantly or decreasing costs of hiring a general, all rendered completely moot once mercenaries were reworked, as it never decays now[[/note]] and related with it drilling[[note]]A specific, exact regiment non-stop training outside of combat, for another scaling modifier to performance. Openly mocked as a gimmick to occupy players army with something during peace time, as the gain of drilling is extremely slow and bonuses provided by it virtually invisible, while tied to specific regiments, rather than all units in general[[/note]] or Prussia-exclusive (thus even more underused) militarisation[[note]]Yet another scaling modifier - see a pattern already? - that increases discipline and decreases maintenance of the Prussian army, but in the same time forcing player to stay at all times at a very small size of a country in a game that ''doesn't support tall gameplay''[[/note]]. Various game mechanics that originally were DLC-exclusive were eventually were moved to core rules and only then reworked into something more impactful, with estates being probably the best example of this.

* UnderusedGameMechanic: It could be argued that ''IV'' is ''build'' from those. The general consensus among players is that due to the design philosophy of [=DLCs=] being self-contained and non-interacting with each other, any mechanic that exists within a DLC is by default shallow and doesn't carry much weight in actual gameplay. Examples include things like innovativeness[[note]]A scaling modifier in regards on how advanced technologically a nation is, gained by rushing technology or adopting an idea first (this one gets exhausted within first 50 years of the game) and utterly meaningless unless reaching 100% value[[/note]], army professionalism[[note]]Another scaling modifier that gives small bonus to dealt damage on national scale and unlocks such stunning abilities like reinforcing a fort instantly or decreasing costs of hiring a general, all rendered completely moot once mercenaries were reworked, as it never decays now[[/note]] and related with it drilling[[note]]A specific, exact regiment non-stop training outside of combat, for another scaling modifier to performance. Openly mocked as a gimmick to occupy players army with something during peace time, as the gain of drilling is extremely slow and bonuses provided by it virtually invisible, while tied to specific regiments, rather than all units in general[[/note]] or Prussia-exclusive (thus even more underused) militarisation[[note]]Yet another scaling modifier - see a pattern already? - that increases discipline and decreases maintenance of the Prussian army, but in the same time forcing player to stay at all times at a very small size of a country in a game that ''doesn't support tall gameplay''[[/note]]. Various game mechanics that originally were DLC-exclusive eventually were moved to core rules and only then reworked into something more impactful, with estates being probably the best example of this.

** Trade nodes as such. The entire thing is pre-definied. No matter how the history will play out, the direction in which the trade is going is fixed and there is no way of changing it. Say you're playing as Korea. Short from conquering most of Manchuria and colonising West Coast of the North America[[note]]Which not only means you are the only country present in that area, but it's ''only'' the West Coast, as any other nodes simply can't send trade toward it[[/note]], you have no inflow to the Nippon node, in which Korea is located. Even if you conquer large part of China, you can't send trade from there, you must instead ''move your collecting node'' to China, sending trade from upward Nippon node there. And it goes like this the entire chain of trade, so if you happen to be a country placed somewhere upward, especially near starting points, you can't in any way trade in nodes down the line, unless you conquer majority of provinces set there and establish it as your new, collecting node. This even affects various European countries, who face the choice between inability to use trade at all, or going on a massive conquest spree, just to get access to different node.

** Also in ''II'', once you hit naval tech '''27'''[[note]]Exploration with all fleets, even if they don't have an explorer. Previous tech level also sets movement time between sea zones at 6 days, allowing to pass 5 zones per month[[/note]], there is no real point funding it any further, as any benefits from that point onward are just meaningless. This allows to save a pretty penny, while still carrying forward on the fact everyone else is going to invest in naval tech anyway, so unless you are the last country of your techgroup with ports, the neighbour bonus alone will fund the naval technology. For the record, the scale goes to '''60''' and stops giving any sort of benefits whatsoever by level 49. And if you play as a nation with historical explorers, you generally don't need naval tech beyond level '''''18'''''[[note]]It allows revealing all coastal provinces the moment a coastal sea zone is discovered and comes almost a century before level 27[[/note]], since you can simply use the explorers you've got to do the job.

* TierInducedScrappy: Playing as a land-locked nation removed roughtly third of gameplay from your experience and in the long run, makes the game unfun, as it cuts you off from all the interactions with naval mechanics. Even just having a single port is more engaging than having none, not to mention the passive effects it have on your nation in ''II'' and ''III''.