Technology modding

Technologies are the advancements you can purchase with monarch points in the Technology interface.

Technology Tables

Although the base game only contains three technology tables (ADM, DIP and MIL), it is possible to add your own.

In /Europa Universalis IV/common/technology.txt, the technology tables are defined in the tables = { } section. For example, to add example_tech, you'd modify the technology.txt like so:

tables = {
	adm_tech = "technologies/adm.txt"
	dip_tech = "technologies/dip.txt"
	mil_tech = "technologies/mil.txt"
        example_tech = "technologies/example.txt"
}

You can then add technologies to /Europa Universalis IV/common/technologies/example.txt.

example_tech_cost_modifier is dynamically generated, and can be used as a country-scope modifier.

Note: currently the AI will not purchase technologies from custom tables and the add_x_tech effects are not dynamically generated, meaning functionally custom tables are only for the player.

Interface

To integrate your new technology table correctly, you have to edit /Europa Universalis IV/interface/countrytechnologyview.gui.

Importantly, you need to create an new windowType that corresponds with your technology table name. For example:

windowType = {
    name = "countrytechnologyview_table_example_tech"
    # ....
}

Note: currently the AI doesn't interact correctly with non-vanilla tables. With the lack of a working add_<name>_tech, it is not recommended you add new tables.

Technologies

Each technology table points to a specific file within /Europa Universalis IV/common/technologies/. These contain the actual technologies that the player and AI can purchase.

There are three internal types of technology: ADM, DIP, MIL. Each type has commands that can only be contained within a file using a certain type.

You set the type for the technology file by placing the following at the top of the file.

monarch_power = <type>  # ADM, DIP or MIL

Ahead of time bonus

This is applied when a nation is ahead of time in one of the three internal types.

Ahead of time bonus accepts any country modifier:

ahead_of_time = {
    production_efficiency = 0.2
}

Technology

Each technology is separated into their own objects. Each object needs a year set, and any technology commands that the technology should apply. It is formatted like so:

technology = {
    year = <year>

    <technology commands>
}

The year is used to determine when to apply the ahead of time cost modifier to the technology cost, and to determine if the country is ahead of time in a technology type.

The order of the technologies in game is the order they appear in the file, descending.

Technology Commands

Name	Type	Example	Notes
<building>	ADM/DIP/MIL	temple = yes	Any building from /Europa Universalis IV/common/buildings/ is valid.
enable = <unit>	DIP/MIL	enable = barque	Any unit from /Europa Universalis IV/common/units/ is valid.
<government>	ADM	tribal_despotism = yes	Any government from /Europa Universalis IV/common/governments/ is valid.
production_efficiency	ADM	production_efficiency = 0.05	Overall maximum a country can have is 2.0 (200%). Stacks additivily.
may_support_rebels	ADM	may_support_rebels = yes
allowed_idea_groups	ADM	allowed_idea_groups = 1	This sets (not adds) the amount, so increment then number in later technologies.
max_states	ADM	max_states = 5	This adds to a country's maximum state count. Stacks additivily.
may_force_march	ADM	may_force_march = yes
administrative_efficiency	ADM	administrative_efficiency = 0.1	Overall maximum a country can have is 1.0 (100%). Stacks additivily.
development_efficiency	ADM	development_efficiency = 0.1	Overall maximum a country can have is 1.0 (100%). Stacks additivily.
naval_morale	DIP	morale = 2.0	Stacks additivily.
naval_maintenance	DIP	naval_maintenance = 0.1	Stacks additivily.
range	DIP	range = 50	Stacks additivily.
global_colonial_growth	DIP	global_colonial_growth = 10	Stacks additivily.
trade_range	DIP	trade_range = 100	Stacks additivily.
trade_efficiency	DIP	trade_efficiency = 0.1	Overall maximum a country can have is 2.0 (200%). Stacks additivily.
num_accepted_cultures	DIP	num_accepted_cultures = 1
may_fabricate_claims	DIP	may_fabricate_claims = yes
merchants	DIP	merchants = yes
reduced_naval_attrition	DIP	reduced_naval_attrition = yes
allow_client_states	DIP	allow_client_states = yes
may_steal_maps	DIP	may_steal_maps = yes
may_study_technology	DIP	may_study_technology = yes
may_slander_merchants	DIP	may_slander_merchants = yes
may_sabotage_recruitment	DIP	may_sabotage_recruitment = yes
may_sow_discontent	DIP	may_sow_discontent = yes
may_sabotage_reputation	DIP	may_sabotage_reputation = yes
may_corrupt_officials	DIP	may_corrupt_officials = yes
may_agitate_for_liberty	DIP	may_agitate_for_liberty = yes
may_infiltrate_administration	DIP	may_infiltrate_administration = yes
sprite_level	MIL	sprite_level = 3	Sets the graphical sprite level to use. 1 to 5 is valid.
infantry_fire	MIL	infantry_fire = 0.1	Stacks additivily.
infantry_shock	MIL	infantry_shock = 0.1	Stacks additivily.
cavalry_fire	MIL	cavalry_fire = 0.1	Stacks additivily.
cavalry_shock	MIL	cavalry_shock = 0.1	Stacks additivily.
artillery_shock	MIL	artillery_shock = 0.1	Stacks additivily.
artillery_fire	MIL	artillery_fire = 0.1	Stacks additivily.
land_morale	MIL	land_morale = 0.1	Stacks additivily.
military_tactics	MIL	military_tactics = 0.1	Stacks additivily.
supply_limit	MIL	supply_limit = 0.25	Stacks additivily.
maneuver_value	MIL	maneuver_value = 0.1	Cavalry flanking bonus.
combat_width	MIL	combat_width = 1	Integers only. Stacks additivily.

Expected Institutions

Technologies contain an expects_institution = { } entry. These blocks contain a list of entries made up of institutions, and tech-cost penalties for not having that institution.
Example:

expects_institution = {
	feudalism = 0.5
	renaissance = 0.5
	new_world_i = 0.5
	printing_press = 0.5
	global_trade = 0.5
	manufactories = 0.15
}

In this example, the first five institutions increase tech costs by +50% if you buy this tech without those institutions. The last institution (Manufactories) only gives a +15% tech cost penalty for trying to buy this tech without having Manufactories embraced.

Localisation

By default the technology localisation is found in /Europa Universalis IV/localisation/technology_l_english.yml.

It is formatted like so:

 <type>_tech_cs_<num>_name: "Tech name here"
 <type>_tech_cs_<num>_desc: "Tech description here"

The number is the index of the technology in its respective file. The first technology is 0, second is 1, etc.

Modding

Audio

Music • Sound

Guides

Adding a province • Save-game editing