EU4 - Development Diary - 24th of October 2017

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DDRJake

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Good day all. As we reach ever closer to the release for Cradle of Civilization which, as you know will be released on...wait, we haven't announced the date yet? Well keep your ears to the ground and you may hear something about that very soon™. In any case, running up to that we have a military mixed-bag of features coming with Cradle that we want to talk about today, as well as a guest appearance from our AI Maestro @Gnivom .

Firstly in Cradle of Civilization we are bringing the ability to Name Generals. Does what it says on the tin: when recruiting a general, you will be able to give them a custom name or roll the die to generate a random name for them. This courtesy is, of course, extended to Conquistadors, Admirals and Explorers.

Name Generals.jpg


As an additional free quality of life change in 1.23, the number of pips your leader may receive is detailed in the tooltip, showing the random spread they will get as well as any bonuses you may get from Ideas and other such modifiers.

Staying on the Military Tab, we can also show the interaction to Slacken Recruitment Standards which will let a nation gain manpower in exchange for allowing somewhat less qualified men into the army. 2 years' worth of manpower can immediately be made available at a cost of 5 professionalism. Naturally, a nation needs to have at least some standards of Professionalism in able to slacken them.

slacken.jpg


Another small addition we have in Cradle is the ability to have compact battle results. This has been requested by the community in the past so we decided to add it into the expansion for those who don't need more than the bare minimum information punctuating the slaughter of war. This can be toggled on and off in the options menu

compact.jpg


Finally, sticking with the military theme, let's talk Templates. They are pretty awesome and remove a lot of micromanagement of recruiting armies. In Cradle of Civilization this is taken a step further with the ability to Conform to Template. In the Unit View, an army can conform to a template that you have specified earlier. Upon selecting a valid template, all superfluous units will detached from the army while required units are built and march directly to merge with the unit.

conform template.jpg


As this feature requires the ability to make templates (an Art of War Expansion feature) to be of any use we are unlocking that feature for owners of Cradle of Civilization too.

Now I'm handing the mic over to the Maestro of AI @Gnivom , to talk about himself and the changes to the AI in v1.23 Persia Update.

###########

Black News Indeed

I have worked on EU4 since February 2016. For the last year or so, I have had the great honour of being the master of its AI. But all things must come to an end, and I have decided to move on to other adventures, outside of Paradox. It is therefore my equally great honour to present to you my successor, @mikesc . These last months, I have taught him what he needs to know, as I was taught last fall. This will be my last week, so today is a good time to talk some about the AI.

AI Improvements
There has been much AI work put into 1.23. I will mention a few improvements here, and for the rest you are referred to the upcoming changelog.

Building AI
This may well be the most notable change, at least for those of you who often play into the late game.

The AI has always been horribly bad at deciding where to build buildings, which means an experienced player could easily be many times richer and stronger than the AI after only 100 years, with the same development. This has now turned around completely. Instead of deciding buildings based on scripted rules, it now calculates precisely how much it will gain from building each building, convert all values to ducats, and consider how big a treasury they need for the return on investment to be worth it. The reaction from QA after their first handsoff game with the new building AI was “You have created a monster”. Indeed, late-game AI is extremely rich.

It probably undervalues manpower and forcelimit at the moment, but that may be for the best.

This doesn’t only make the game harder however, as an expanding player will get a lot of free buildings.

Power Balance Threat
One feature in the AI that I believe was added by Chaingun, is called Power Balance Threat (PBT). It means that each AI determines another country, if applicable, that it considers a long-term strategic threat/rival. It will then try to weaken this country in subtle ways, such as sending gifts to or guaranteeing their neighbors. Allies can also be picked as PBT. The algorithm for determining PBT focuses on large and/or quickly expanding nations. Since this very often targets the player’s nation, the algorithm has been explicitly prohibited from selecting the player’s country, except on Hard and Very Hard. My understanding is that this was to avoid the perception of the AI targeting the player because of it being the player. This block has now been removed on Normal difficulty as well.

You may now see even your allies act to slow down your growth, and some countries getting worse attitudes towards you, but don’t expect a huge difference.

Other Changes/Improvements
Many people have complained about the AI’s use of Edicts, and correctly so. From 1.23, it will spend a lot less money on Edicts.

AI aggressiveness has been slightly tuned down, especially when in debt.

Many small improvements have been put into the army AI. For example fixing many cases where it pathed through, rather than around, enemy armies (often leading to just cancelling the movement anyway).

Many more improvements will be found in the changelog.

I am currently spending my last week at Paradox trying to make some major improvements to army AI, that will be incorporated after 1.23.

Cheats

My personal opinion has always been that the AI should cheat as little as possible - that the player should play the game at equal terms with the AI. I believe the EU4 AI follows this philosophy more than any other strategy game I have played (at least on normal difficulty).

The cheats that do exist are typically not to make the AI more powerful, but to work as lubricant where the AI is not as precise as the player (which could be to avoid more complicated and bug prone code, or unnecessary computing power). A good example is the extra diplomat, which is only used for one-time actions. The obvious exception is the Lucky Nation bonuses, which are not available to the player.

So, let’s mention some of the cheats that do (and do not) exist:

There are maybe a dozen places in diplomatic AI, where it is nicer towards other AI in specific cases that make sense but could potentially be exploited by the player. It may for example call in allies as if with Promise Land clicked, without then being bound to actually give land. It will however try to give if possible.

The AI does not cheat with dice rolls in battles (or sieges, or anyplace else that I can think of)

The AI no longer cheats with Fort Maintenance, since a few patches back.
EDIT: There is still a bug that they can cheat anyway sometimes. See https://forum.paradoxplaza.com/forum/index.php?threads/1-22-2-vassal-not-paying-for-forts.1052067/ .

The AI doesn’t cheat with Fort Zone of Control. Nor was it ever meant to, although there has been at least one bug in the past where it could in rare cases.

Other than the Fort Zone of Control, the AI/Player cheats currently mentioned on the wiki are correct (to my best knowledge).

Additional considerations:

  • The AI may sometimes look up underlying numbers that are not available to the player.
  • The AI sometimes restrains itself to get a more historical outcome.
  • The AI is not allowed to pause the game, and has to play hundreds of nations simultaneously. Nor does it use the extra time it could get when the player pauses, or plays on speeds lower than 5 (so that behaviour isn’t affected by game speed).
/Gnivom

###########

Thanks a lot for that Gnivom. Next week we will have another guest speaker from the team to talk about a huge project we've undertaken for the game which, so far, we have managed to keep completely secret and will be rolling out with 1.23. See you then!
 
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DDRJake

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RIP DDRJake T_T

Oh I'm very much alive.

Is there a cooldown on slackening recruiting standards or is it only limited by your professionalism?

It's limited purely by your professionalism.

Yeah me too! Why can't developer diaries be daily?!

Well sure, if you're happy with Development Diaries about features we would hypothetically make if we weren't trapped in a Box Quest-esque cycle of writing nonstop diaries every working hour.

yo DDR my buddy, my friend, mi amigo can you give us a bit more of that release date?

Yeah okay.

Paradox introduces Army Professionalism which, among others, increases when building military buildings. AI now less likely to build those buildings :confused: Oh well at least it will be richer and can spam mercs more cheaply from low professionalism

In testing, we actually found the tie between buildings and professionalism to be an unintended level of pain to use, so it has been removed from impacting on professionalism. It is impacted by hiring generals, Drilling, events and decisions.

Naming a general before you see his stats ? Jake The Swift could end up being Jake the Crippled

Story of my dancing life.

did you just announced of announcement of new pdx game?

No.

Think it means you need to own either Art of War or Cradle of Civilisation to get it.

Correct.

Can you add general age? It would be nice to see how long they have left. Would help determine if a war should be postponed since your best general is of old age.

This is not currently in the game, but I agree that it would be a good addition.
 

Gnivom

Revived AI programmer
Feb 8, 2016
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Oh, I forgot to mention that the AI is now able to declare wars on overseas countries (such as Ottomans on The Knights, or Japan on Korea) again. (For two years it has been unable to, except against Primitives and in Independence, Coalition, and Religious League wars)

Oh well, I guess people might see it in the changelog...
 

DDRJake

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Gnivom

Revived AI programmer
Feb 8, 2016
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@Gnivom do this changes to the AI make it better at colonizing? Currently Spain and Portugal are barely able to colonize and the institution always spawns in Britain.
The AI is slightly better at colonizing in 1.23. In our current handsoff games, they do ok with colonization when not distracted too much in Europe (Aragon or France conquering Castile, Castile or Morocco invading Portugal). Emphasis on _slightly_ and _ok_ though.
 

Gnivom

Revived AI programmer
Feb 8, 2016
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this slackening standards may be useful but i would be sad if AI will spam this
when i played EU4 and AI passed my forts without capturing them, but it is good to know that it was just a bug
It will not spam Slacken Recruitment Standards. However, few AI countries manage to keep really high AP anyway, due to reliance on mercenaries as some have mentioned. This has been taken into consideration, and the AI tries somewhat to avoid mercenaries, but will still recruit lots of them whenever it feels like it needs to.
 

Gnivom

Revived AI programmer
Feb 8, 2016
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443
Realy? I mean obviously You guys know your own game better than us but... The AI just walks through my forts in every single game I've ever played, in the past or current. I was under the understanding that if the AI can somehow reach a province, it will cheat and take the shortest route available to make it easier on the AI. I thought that was stated some time back when the potential fort changes were discussed (which were canceled). It's still the number one most frustrating thing I face in my EU4 games honestly. Allies run past forts that I can't run past, and get crushed by enemy armies because I cannot support them. Or enemies just march through my forts, taking a very short route to easily be able to wipe out my shattered armies for example, despite forts being in place that should force the AI to take a much longer route. If this is not intended, then this is a bug that is not rare, but present in all my games in every war. :/
You just mentioned the bug I was thinking of, and it was fixed several patches ago.
I do think you are probably missing some fringe rule in those cases. If you ever see the AI make a move that should be illegal, if you're not in Ironman mode or multiplayer you can use the console to change country to that nation and see if you could make the same move. If not, it's certainly a bug.
(Note that I am now only speaking on my own behalf)