Coming from primarily playing EU2 -- I hope this doesn't end up being like the badboy mechanic in that game. That was a pretty artificial-feeling and poorly-executed mechanic.
It's probably worth noting that that particular mechanic was a product of different times. Grand strategy simply was different at that point in time, as were some other genres. Badboy was a useful mechanic in terms of realism as well, but it is also has the feel of one of those classic mechanics governing human-AI relations in a game (which is not to say that it didn't apply to AI). At that point in time, several years ago, or rather a dozen-odd years ago, it was acceptable for mechanics to be a rock-paper-scissors kind of high abstraction, with even some special rules for the human player. These days I think realism is preferred.
This may also have something to do with how realistic graphics, sound etc. take us away from computer games as beefed-up chessboards (think 320*200 or 640*480 pixels as screen resolution and 16, later 256 colours — you can
only approximate and be figurative with that) to computer games as simulators of this or that variety.
I know that as someone who misses those old games fondly, I still prefer to have 'behavioral' realism in modern games that have realistic graphics and sounds, with the sole exception of logical games (e.g. something like Gruntz, which is very clearly meant to be metaphorical).
It still needs noting that in those old times strategy designers and coders did come up with elaborate algorithms to avoid making the rock-paper-and-scissors too obvious; the schematism of the mechanics was something you could trace and analyse if you cared, but it was understated, softened, retouched, disguised cleverly with sometimes relatively simple means.
Consequently, when a modern game like CK2 starts making mechanics very obvious and very simplistic, it's not going to be well received. On the other hand the game has some dialogue (and King Arthur did a splendid job in that regard) which with the use of some well-written text hides the rigid bones behind soft flesh.
Essentially, you'd accrue BB for aggressive conquests regardless of religion/culture, and at high levels your internal stability would plummet and you'd start drawing DoWs. Cross the magical limit and you'd get constant forced civil wars (just rebel-crushing turned to 11) and "badboy wars" in which literally everyone on the same continent as your capital or neighboring you would attack you as often as possible.
… And one of those old presumptions of old times was that the purpose of AI was to make it challenging for the human player, which often resulted in behaviours that — if we were to look at AI in a more behavioral, psychological light — resembled disinterested dogged persecution, some kind of selfless antagonism where the AI seeks to destroy you even if it won't benefit AI's interests, even if it will make AI go down with you etc.
I'm well aware that some of the old guard might actually be not only well used to but also favourably predisposed to that vision of AI's purpose, but I think players in general, these days, will be more inclined to expect AI to mimic human behaviour — especially in something that's supposed to act like a strategy/roleplaying hybrid rather than a war/history-themed logical game. Challenge (difficulty) and playability (ease) will still need to temper realism (and often more than just a little), but AI needs more psychology, emulation, or at least some basic logic, common sense, that doesn't evolve around the no. 1 goal of opposing the human player.
From the dev diary it doesn't look like the human player will be treated with either prejudice or favour, but if venerable legacy mechanics are brought up in discussion, I feel this all needs to be mentioned in order to put the discussion in perspective.
It was crude in that it was actually worse for conquering same-religion nations but applied equally to everyone, so, for example, Europeans would consider the Ottomans more of a threat if they conquered their own Sunni neighbors than if they expanded into Eastern Europe.
There definitely needs to be distinction drawn on the basis of religion — not being more tolerant of high Infamy in someone who shares your religion, that would mean the HRE being tolerant of France's infamy for eating Spain, for example), not being more tolerant about people who attack only their religious 'enemies'. France may be more tolerant of Castilian holy wars than of Fatimid holy wars for sure, but a European Christian power would not be more tolerant of, say, the Ottomans gobbling up neighbouring Turkish minors than Balkan Christian states. Hence, the distinction needs to be drawn on both ends of the stick compared to the 'beholder's' religion. Pure expansion/badboy penalty cannot accurately reflect this.
The civil wars were silly, in that an OE that smashed through nothing more than the small Anatolia countries, Byzantium, and say, Serbia, would be on the verge of unending civil wars. Had to game the system by feeding allies to avoid accruing BB, which just felt really constructed and fake.
There is a similar problem with CBs in CK2 right now where you sometimes can't join people's defensive wars for really artificial reasons (starting with Catholic vs Orthodox, like your differences don't pale before the differences you both have with the approaching Sunni army), which can make you declare your own aggressive wars vs the aggressor or join some other wars and then do gamey things like attaching your troops to the ally's army so that the ally can use the greater numbers even against people you, yourself, aren't currently at war with. (Suppose you're alredy helping France against the HRE, but then England also DoWs France, and you can't join that war, you won't be hostile to English troops. You can still attach your army to the French army, and your soldiers
will fight English troops whenever the French stack does.)
Worse, you had to essentially sit around for 50-100 years waiting for the number to tick down before doing anything else, once you were near the limit, if you didn't want to pass it. Kind of a cooling-off period without any real reason for it other than the existence said number.
That's one of those situations where you can't escape having a somewhat simplified mathematical formula govern the whole thing, which won't provide great depth for every possible situation in the game, but you can still do some careful thinking and devise a set of conditions, triggers and counters and offsets in order to cover at least the most typical, most expectable needs for nuance. (E.g. dynasty change, religion change, relative validity of your reasons/context of your actions etc.)
It also could be exploited to get free wars. Since everyone would DoW you constantly once over the limit, you could freely fight them and expand without having to take the negatives for declaring war yourself. In CK that wouldn't be as much of an issue, as you can't just grab territory in random defensive wars, but it'd still give you the opportunity to take prisoners and smash other realms' armies to nothingness, which can certainly set the table for wars of conquest later on.
Well, you can, but still at the price of bleeding your own army and treasury, so it's not really such a great bargain. And if you bleed whomever declared those wars on you, you will still need to declare your own aggressive wars if you wanted to benefit from those folks' prone condition. Likely, somebody else will. Not necessarily someone you like.
In fact, in mediaeval Europe, if you're in a central position, bleeding your neighbours means exposing them to a Muslim threat, and expanded Muslims are very likely going to be more of a pain to you than whomever you fought in Europe. This may also be true the other way round, i.e. if you play as a centrally located Muslim and weaken the outliers, after which they get hit by holy wars and crusades from their Christian neighbours.
In any case the AI needs to consider its chances of victory and also its other threats — not just who is a bigger threat but also what happens if you lose the war. (For example if you play in Spain France may be a greater threat than a Muslim sultanate in terms of raw power, but France doesn't have kingdom-level CBs, not even Invasion, because you're smaller than they are. If the Sultanate bleeds you, France can move in and take like 1 county, or perhaps press someone's claim to a duchy. But any neighbouring Sultanate can go for your entire kingdom.)
I also worry how this would apply to the Byzantines or Iberians -- realms that face both expansion opportunities and threats from holy wars. I don't think expanding Christendom into southern Iberia or the Mideast would be seen by other Christian countries as a threat (though it certainly would by Muslims),
Almost definitely not in Iberia, unless from the perspective of a close neighbour (e.g. weakened France vs a large, strong Iberian realm with some claims on France). Byzantium would be a bit more complicated — it did tend to have a sour relationship with its Christian neighbours. It's conceivable to think that they might want to ally with a Muslim fellow target of the same Byzantine expanionism/restorationism (or just see the threat resulting from BYZ either increasing its levy and income base or just simply securing its borders, eliminating threats, freeing them up to turn against Christian neighbours after sorting it out with Muslims). Having a common enemy, even a common threat, sometimes results in unlikely alliances.
but it sounds like this mechanic could treat it as such (as it appears to be just a single univeral number). And their vulnerability to holy wars means it could punish such border lands disproportionately.
Yes, that's a problem. And especially with strangers from faraway — with holy-war/crusade CBs available because of belonging to a different religious group — taking it upon themselves to police you for being rough with your neighbours. I can see a Mediterranean Catholic power requesting a crusade against e.g. huge k_Africa or against the Fatimids currently jihading in Persia, though, so this is not a 0/1 issue, it's a question of 'how much is appropriate'.
Too add to
@brobman22 's response. Sometimes Paradox makes changes to their games that upsets a portion of their player base. Paradox's usual response is "suck it up, or mod it out."
Yes, and not to beat them for it right now, it's an unresolved problem that, well, remains unresolved. This is probably worth noting in the context of the number of 'Respectfully Disagrees' this particular Dev Diary has received compared to its 'Agrees'. I need to stress that neither 'suck it up' nor 'mod it out' is acceptable in the context of vanilla/obligatory changes to a game with a long streak of DLCs that people have already purchased, not to mention the amount of non-monetary
time and emotional attachment players have made. Well, it never really is acceptable, that kind of answer, but especially not in this kind of context. And especially not in the context of patch changes being somewhat reputed for a short approval process and insufficient QA at least as often than not (please realize that this is an approximate factual statistic, it's not an unfair generalization, I'm not detailing the calculations in order to conserve space in what's already a long post), in addition to a certain indecision and experimental attitude.
Plus, people have been asking Paradox to limit expansion in CK2 for a while. So it's not like this change is unwarranted.
Yes, and thinking about it, exploring the whole angle, is a step in the right direction. It's much welcome and much appreciated. With 3000 hours into this game, I have come to observe a certain dullness in the AI being rather passive. I tend to have likeable (virtuous but not only) player characters and pay attention to diplomacy, so this means I'm bound to face fewer declarations of war than most people, but still, I do think shaking it up and making AI react to threats, expansionism etc. is going to make the game more dynamic, more interesting.
… And limit expansion, and that's a good thing. The game is supposed to be (in so far as a sandbox game can be supposed to be anything specific — I'm going by what the
score is based upon when your achievements are evaluated at end game) about prestige and piety. Also the CB system promotes permanence of possession at least among Christian rulers. For all the wars that keep going on all the time the game does actually reflect those elements of a certain institutional pacifism in Christianity. Which means doing all the things medieval rulers are doing, being able to try and do the more groundshaking things they were theoretically capable of doing (but less often getting completely away with), but principally staying within your de iure limits. (Which is also the point of de iure, gavelkind etc. — note how in Gavelkind you can end up ruling a fraction of your previous territory upon succession, which doesn't nullify your prestige or piety or the 'legitimacy' of your game or realm or whatever.)
When the Ummayyad's seized power in southern Iberia in the late 8th century, the northern Muslim rulers sought an alliance with Charlemagne. I think this would be best represented with a coalition.
Assuming the system is anything like the current system in EU4, distance will be a factor. So in this case the Christian lord's 100% dislike of the Seljuks would be modified by the fact that they are so far away, giving you a number somewhere between 100% and 0% - which seems right to me. The western Europeans would be unlikely to join a coalition against the Seljuks unless they expand westward enough to actually become a threat, at which point they would start to get worried about the giant Muslim empire that has been overrunning everything in its path and was now within striking distance of Rome.
(And others who said something about this particular subject).
I would hate to leave you guys without sources, but if you can dig up Runciman or just go through the history of k_Jerusalem on Wikipedia and carefully check the belligerents on both sides — the success of the initial crusades and then the initial survival of crusader states in Palestine and Syria was partly made possible by divisions within the Muslim camp, or even the lack of a single Muslim camp. There were often Muslim on both sides of the conflict, and even both Christians and Muslims on either side.
In Iberia there were not too rarely both Christians and Muslims on either side of the conflict. After the Sack of Constantinople, Orthodox-Muslim alliances against Catholics weren't out of the question either. Or Norse pagans in British Isles.
There is already some of that in the game, considering how e.g. Christian relatives and friends
will join a Muslim's or a heretic's holy war against Catholics. You could even have Catholics defending against a crusade — not likely the target's coreligionists joining the crusade, but even that's not impossible (it's not impossible for a pope to have Muslim or pagan or especially heretic relatives).
Only, your coreligionists shouldn't normally 'hate' you for holy wars and other religion-related CBs as much as the rest of the world does. Fear you, feel apprehensive, sure, just not the kind of ignominy that the word 'Infamy' conveys. But I want to stress this needs a lot of nuance, it's not a black-and-white 0/1 issue. It's a quantitative, not a qualitative matter.