Game start modding

Version

Please help with verifying or updating older sections of this article. At least some were last verified for version 3.2.

This article is for the PC version of Stellaris only.

It can be confusing, especially to new modders, how exactly the game sets up a new Galaxy and how to modify anything during Game Setup. Here is a quick reference for everything that the Vanilla game does when setting up a new game.

To understand this page, it is recommended you familiarize yourself with Events and On Actions.

Game Start Modding[]

The most-compatible way to mod game setup is to add custom events that file after the built-in game events. It is also possible to fire events before built-in events. The reason that events are the most compatible way to do this is that they don't overwrite any of the built-in effects or effects, and thus won't conflict with other mods that also want to edit the game setup process.

For adding technologies, use the on_action empire_init_add_technologies which is called once per country. This is the intended place to grant free technologies as part of an origin, civic, or other custom startup conditions. Here is a sample event:

country_event = {
	id = my_event.1
	is_triggered_only = yes
	hide_window = yes
	trigger = {
		# your conditions go here
		is_regular_empire = yes
		OR = {
			has_valid_civic = civic_corporate_dominion
			is_megacorp = yes
			has_valid_civic = civic_merchant_guilds
		}
	}
	immediate = {
		# grant technologies here
		give_technology = {
			tech = tech_space_trading
			message = no
		}
	}
}

For adjusting the starting conditions on an empire's homeworld, use the on_action empire_init_capital_planet which is called once per country in the scope of that empire's capital planet. Here is a sample event:

planet_event = {
	id = my_event.2
	is_triggered_only = yes
	hide_window = yes
	pre_triggers = {
		has_owner = yes
	}
	trigger = {
		# your conditions go here - notice how it scopes to the planet's owner
		owner = {
			is_regular_empire = yes
			OR = {
				has_valid_civic = civic_corporate_dominion
				is_megacorp = yes
				has_valid_civic = civic_merchant_guilds
			}
		}
		free_building_slots > 0 # this checks that the planet has space for a building
	}
	immediate = {
		# make changes to the capital planet here, you can scope to the solar system like this: solar_system = { <code here> }
		add_building = building_galactic_stock_exchange
	}
}

A special case for game setup is creating a new origin or civic with a secondary species. The built-in code will not correctly spawn secondary Pops. Instead, it is recommended to follow this template that uses an on_action to disable the built-in setup event for the relevant empire(s), and then spawns Pops as desired for the primary and secondary species but also executes the built-in capital district/building/blocker, and so on code.

Review the Game Start Execution Order section for the full details of the when code executes as a new game is starting.

Game Start Execution Order[]

After pressing PLAY on the Game Details screen to begin a new game, scripts execute in the following order:

Galaxy is created, using common/solar_system_initializers (See System modding)

generate_empire_home_planet
generate_home_system_resources

on_action empire_init_add_technologies is called

event game_start.8 - Adds starting resources to Empires and some techs for specific Origins and Civics

on_action empire_init_capital_planet

event game_start.12 - Sets up capital planets by calling the following scripted effects:

(excludes set_planet_flag = special_start_planet from solar_system_initializers)

generate_start_deposits_and_blockers
generate_start_buildings_and_districts
generate_start_pops
generate_home_planet_final_pass
void_dweller_home_planet_setup

on_action empire_init_create_ships

event game_start.9 - Creates beginning ships for Empires

on_action on_initialize_advanced_colony

Only for the extra colonies of AI empires that were flagged as Advanced Starts by the engine during Galaxy creation.

events game_start.20 through game_start.23 - Sets up the additional colonies and creates their pops

on_action on_become_advanced_empire

event game_start.6 - adds more starting Resources, technologies, and builds more Mining and Research stations

on_action on_game_start

event game_start.1 - Lots of necessary things that the engine requires, as well as setting up flavor events for the player and/or certain Origins/Civics
event game_start.2 - Clears Planet Modifiers from Capital planets
event game_start.3 - Sets up Advisor and Tutorial
event game_start.5 - Sets up the Nomad Fleet (If Megacorp is NOT active)
event game_start.31 - Spawns Wormholes

If DLC Distant Stars is active:

event distar.290 - Create Corrupted Avatar system
event distar.252 - Setup Phaseshifting Planet (if Galaxy creation spawned it from solar_system_initializers)
event distar.295 - If Ratling systems spawned, make sure they have Hyperlane connections
event distar.8000 - Randomize L-Gate outcome

event colony_mod.100 - Adds Titanic Life blocker to planets with the Planet Modifier
event game_start.50 - Setup Nebula effects for systems in Nebulas
event galactic_features.406 - spawn VLUUR
event clones.1 - Make Clone Army pops unable to be Genetically Modified
event central.1 - Chance to initialize the Central Crystal event chain for Void Dwellers
event akx.8000 - Chance to initialize the Horizon Signal system

on_action on_game_start_country

event game_start.33 - Setup conditions for specific Origins/Civics, and build starting home system Mining and Research Stations
event game_start.10 - Setup orbital stations and customizations for Fallen Empires
event necroids.4 - Switch Guaranteed Habitable Planets to Primitives for Necrophage Origin
event clones.2 - Give Cloning techs to Clone Army Origins
event clones.3 - Initialize Clone Vats for Clone Army Origins