HOI4 Dev Diary - 1.3.3 modding features

  • We have updated our Community Code of Conduct. Please read through the new rules for the forum that are an integral part of Paradox Interactive’s User Agreement.


Aug 11, 2015
Hi everyone,

As mentioned in last weeks diary, I wanted to go a little more into detail with a few of the changes modders can look forward to in 1.3.3.

Tech trees
A part of HOI4 we've often seen modded are the technology trees, specifically adding trees that are unique to one nation. This has so far been achieved with a clever little trick, where the first technology in a tree only is available to a certain nation. This does achieve the goal, but it also means all trees are visible, even though the player can never research them. In 1.3.3 we've added dynamic technology folders, which hides and locks any technology in the folder that does not meet the trigger. I've taken a book out of my click bait add and prepared a little before and after sample using BICE as an example of how the new mod feature looks.

Obviously they could chose to remove all the original folders and replace with country unique ones, but that's up to the BICE guys.
This does technically work with any trigger, but I recommend primarily using it for tags. Enabling during the game and and keeping it enabled for the rest of the game should not be a problem.

One of our focuses for 1.3.3 is to improve industrial balance. We will talk more about that in the future (when its actually done :D) but this has led to some new features modders have requested as well. Its now possible to separate the industrial bonuses between factories and dockyards for example (helpful for balancing concentrated vs dispersed industry also) as well as now being able to control the max number of factories assignable to production lines (some mods like to limit the max for naval construction for example so you produce more in parallel rather than serially) but so far this was only possible by limiting UI for player. Now it can be set separately for military, civilian and naval lines.

Change state names

Changing victory point names

Of course modders have also wanted to be able to change names of cities, and now you can!

More is more!
These new features will amaze you. I can't believe no 5
Apologies if some have already been mentioned =)

-Added trigger to technology folders. Will hide tab and disable research for techs if trigger is not met.

-Split up factory modifier into a new industrial_capacity_dockyard so dockyards get their own progression

-Added local_non_core_manpower state modifier

-Added effect add_state_modifier

-Added an on action for on_annex. Fired from both effect and peaceconference.

-Fixed on_civil_war_end having a fixed random seed

-Added has_country_leader trigger

-The AI is no longer quite as emotionally attached to modded ideas. Will now consider changing non-hardcoded ideas if the ai_will_do value is higher than the existing idea.

-Added new ai strategy "template_xp_reserve" that lets you modify how much AI wants to burn or not burn its xp for division design
-Added proper error handling when reading scripted ai strategies

-Added can_join_factions rule

-Added trigger has_tech_bonus. Works with specific technology or category

-Added has_resources_amount trigger

-Added on_startup to onactions

-Added count_triggers ( same as calc_true_if on other projects )

-Added set_state_category

-Added set_state_name

The rest of the team are squashing bugs, working on late game performance and as always improving the AI.

Also don't forget to tune in at 16:00CET on www.twitch.tv/paradoxinteractive today where we will be checking out Millennium Dawn: Modern Day Mod in our series of mod highlights in World War Wednesday!
Last edited by a moderator:
  • 82
  • 33
  • 5
All these changes are amazing and will be greatly helpful for modding, I have some plans for them already :)

I also hope you guys will enjoy playing Millennium Dawn. Have fun! I'll stick around in the chat I hope.
  • 16
  • 2
  • 1
So, are there any plans for the new modding features being used in the base game ?

Notably renaming cities and states. Dynamic province names come to mind, same goes with some alternative names historically given by Germany to USSR cities
  • 2
So, are there any plans for the new modding features being used in the base game ?

the name change ones you see in the diary are in, as for more, maaaaaybe :3
  • 23
  • 1
Nice set of changes. Limiting the number of dockyards is a nice change option, and I thought it being controlled in the UI file was odd. Nice to be able to change names of states and cities. Still hope to be able to change templates by event some day though...
  • 2
-Added local_non_core_manpower state modifier

@Havebeard correct me if I am wrong, but does that allow me to kinda implement the "partial cores" I mentioned in the requests thread? Can this modifier be altered during the game, such as on the change of controller, allowing the state to give more manpower to a given owner?
Nice to see you used my design as an example
  • 13
  • 1
I've taken a book out of my click bait add and prepared a little before and after sample using BICE as an example of how the new mod feature looks.
Will it be possible to hide or replace the generic tree? For example, in those pictures, to have the German tank button replace the generic tank tech button?
  • 3
mmmm @Havebeard it is good to see so many of my requests being implemented, I commit myself entirely to making sure that HOI IV is as good of a mod platform as CKII is currently. @podcat is there any possible update as to when 1.33 will drop?
  • 1
Do these new trees fix the incompatibility with other tech expansions? currently, no two mods adding single tech trees are compatible without doing a compatch because of how the .GUI file works. Will this new update change that at all?
  • 1
One final question, will you be able to document the new mod features in the coming patch notes? I am aware it can be tedious, but it has always been a crusade for me to push for better documentation, especially with the wiki's in such a sad state of disrepair.

Oh and a last aside, can we get a similar building_slot modifier for non core states as you have included for non-core manpower? This would be quite useful to enable so that we can have a conquering empire not lose out on factories due to annexing rather than puppeting.
  • 3