Hello everyone and welcome to a rather meaty development diary for Europa Universalis IV. This week we’ll release 1.31.6, which is a compatibility patch for the launch on Epic Store, where EU4 will be freely available for a short period of time.
This patch does not contain any bug fixes, improvements or balance changes, as we had to make sure we had a stable version for this release. Some of our programmers and qa have been working diligently to create this new version for a long while now.
Meanwhile the core-team have been working on the major 1.32 patch which we aim to have out later this year. While the other development diaries will focus mostly on what content we will add to the immersion pack, today we will talk about a lot of balance changes!
Concentrate Development
As we all know, the Concentrate Development feature, while technically working as designed, has a few drawbacks, as it can become very unbalanced and immersion breaking. For 1.32 we have been reworking this.
Now when you pillage or concentrate a set of provinces, the horde “raze” function is called, but with 20% reduction of the development. This is then converted into monarch points in the source province(s), using the cost it would improve development in each of these provinces.
These “monarch points” are then taken to the capital of your country, with a loss of 20% of points when applicable, as some countries have free concentrate development. What is left is then used to “buy” development in your capital province. Any “monarch points” left over are then lost.
A shout out to the post who inspired this new design!
We also fixed the way you could concentrate development twice, by first owning it, and then from the released vassal. Liberty desire now also increases for the subjects when you concentrate their development.
Misc Balance Changes
The catholic curia powers are gaining some improvements in 1.32 as well, with all getting another bonus and here are some examples.
- Bless Ruler - Now also gives +10% Land Morale
- Indulgence for Sin - Now gives +10% Improve Relations
- Send Papal Legate- Also adds 10% cheaper annexation costs.
We made some tweaks to curry favors, so that it now relies far more on relative military power, so it's harder to gain for a smaller, weaker nation.
When it comes to natives, we added a new reform to slow down the path to becoming a duchy for settled tribes, as well as adding feudalism as a requirement.
We also added in cooldowns for migration into non-owned lands, made costs for adding tribal land that scales with owned provinces and development. There are also penalties for migration into winter territory. Also added a relation penalty that increases each month that a tribe is inside tribal land of another country.
And of course we are rebalancing, i.e. nerfing, the native development growth for 1.32, as it is completely unrealistic and does not work with the rest of the game.
We also changed when the AI released vassals for being over the governing capacity to be a much higher threshold, and also giving lucky nations a nice little boost to their governing capacity.
Now I hand over the keys to Gnivom who will talk about some changes to Institutions and the AI for 1.32
Institution Changes
We’ve decided to change how Institutions affect tech cost.
So what was the problem?
We all know how Institutions work:
Hard to take seriously indeed
Countries outside of Europe, and especially in the Americas and sub-Saharan Africa, have to pay more for a technology the longer they wait. This means they’re in a hectic struggle against time, as those who fall behind their neighbors will struggle to catch up.
The New System
From 1.32, every technology has a fixed set of required institutions. If you haven’t yet embraced one or more required institutions, that technology costs you 50% more for each.
This updated Technology View should hopefully be self explanatory:
These are some nice properties of the new system over the old:
- Institutions now cause a rubber-band effect on tech instead of a snowball effect
- Some movement in Florence doesn’t magically affect the Aztecs (until it actually spreads there)
- An institution spawning is now a good thing
Asian nations will find themselves getting hit by a +50% tech cost from Renaissance earlier than they would in 1.31, but as they get further behind, their tech cost will stabilize even if they don’t develop for institutions.
European nations won’t be affected as much, but those on the forefront of technology will notice the increased tech cost, making institutions more relevant in this region than previously.
When changing the code for this, it turned out we based a lot of seemingly unrelated things on countries’ “tech cost from institutions”, most of which were simply translated from the pre-Rights of Man “technology group” system. For example, joining a Trade League requires having at most +200% tech cost from institutions. Who would have known? You’ll find a lot of these addressed in 1.32’s changelog.
AI Improvements
Every version of EU4 has had its own AI issues, and it’s no secret that it has been getting worse for a while. For 1.32 some of the most debilitating issues have been fixed, and hopefully without causing too many new ones.
EU4’s AI is the product of years of incremental development, by a large number of developers. Most of the code is written after EU4’s release, but a few lines date back as far as the late 90’s. Writing AI is hard, so many of the systems are complex. And given the number of different developers, they don’t all work in harmony. Essentially, for any given choice the AI has to make in army, navy or budgeting; it often has a dozen or so voices in its head telling it what to do. It’s supposed to take all of them into account, but often the loudest voice drowns out all the rest.
(yes, lower numbers are better)
Here, the Ottoman army has made good progress on the Mamluk fort of Tabuk. But a voice intended for a completely different situation screams one order of magnitude louder than all other voices, that it should kill the rebels in Qahirah.
Issues like this hinder the systems that *are* made for the given situation from doing their job. A lot of what has been done for 1.32’s AI is to find and fix cases where systems interfere with each other.
Major Fixes
Army
This is really the result of a bunch of small fixes, but essentially the AI will generally be more competent at achieving stuff with its armies, although individual moves can still be erratic. They will also keep a more significant army in peacetime
Naval Invasions
The AI can now decently perform naval invasions again, without too much shenanigans. This has a huge impact on the European AIs’ colonization efforts.
An almost fully colonized New World from one of our observer runs
Economy
Lots of small fixes mean the AI’s economy should now be more solid. Budgeting has been improved and the choice of buildings to construct puts more emphasis on expected financial return.
A special shoutout to [USER=1294106]@Tempscire[/USER], whose reverse engineering of AI army behavior is somehow easier to understand than the code itself. We implemented his suggestion for terrain evaluation as-is, and changed how combat width is considered, albeit not as he suggested for technical reasons. Unfortunately he has many other good suggestions that will not be implemented at this point.