Pop Faction modding

Version

Please help with verifying or updating older sections of this article. At least some were last verified for version 2.6.

This article is for the PC version of Stellaris only.

This page is about how to modify existing and how to create new Factions.

Factions are defined at "common/pop_faction_types/xxx.txt".

Data Structure

Property	Description
election_header = <GFX entry key>	Determines the header texture to be attached to the leader entry in democratic election window.  Democratic governments will use at least the current ruler and the leader of each faction as election candidates and faction leaders will use this header texture and have their faction names written on it. Leaders without any factions will use a fallback header texture that reads "Independent".
guiding_ethic = <ethic key>	Determines the guiding ethic of this faction. Since the visible "guiding ethic" is part of the flavor text and all other references to ethics related with factions have nothing to do with this property, it's unclear what does this property actually do.
unique = <yes/no>	If yes, only one instance of this faction can exist in an Empire. Vanilla factions always have "yes".
support_multiplier = <float>	Unclear. Vanilla factions always have "1".
resources	An Economy Unit to determine the resource production of this faction. The production is mulitplied by faction support rate and faction approval. Vanilla factions always have economy category pop_factions. Also, they always produce  Influence +2, resulting in all factions produce at most 2 influence in total.
is_potential	A block of Conditions to determine should an Empire have this faction. Vanilla factions always exclude  Gestalt Consciousness and require 10 years have been passed since start of the game and have once encountered another species.
parameters	Pre-defined parameters to be called by Faction Actions. Vanilla always define it like this, making parameter:empire usable in Faction Actions to scope to the Empire this faction is in. parameters = { empire = { type = country valid_objects = { is_same_value = root } } }
can_join_pre_triggers	A block of Pseudo-Conditions to determine can a Pop join this faction. Only the following yes-or-no questions are allowed. Vanilla always have is_enslaved = no and is_being_purged = no. Without the pre-triggers, the whole set of conditions will be evaluated once for each of the thousands of Pops in the galaxy, which can be performance intensive. has_owner is_enslaved is_being_purged is_being_assimilated has_planet is_sapient
can_join_faction	A block of Conditions to determine can a Pop join this faction. Vanilla always require the Pop to have the relevant ethics. (Pop scope)
attraction	Determines the attraction to Pops of this faction. Vanilla factions always have 100 base attraction, x1.25 attraction to Pops with citizenship rights, x1.25 if faction leader is the current ruler, and x0.75 if faction has no leaders. However, a Pop can only meet the requirements of up to one faction at a time while faction leader is chosen randomly and cannot be unassigned and will be randomly chosen again if current leader is fired or diseased, making this field entirely irrelevant.
leader	Determines how likely a leader will be randomly chosen as the leader of this faction. Vanilla always have 100 base weight and x0 for event leaders. Supermacist factions will exclude alien leaders as well, or an alien talking about human superiority can be immersion breaking. If no leaders have a weight greater than 0, the faction will still be created but remain leaderless for the rest of the game.
demand	An entry of a faction issue. Multiple allowed.
title = <localisation key> unfulfilled_title = <localisation key> desc = <localisation key>	The flavor text part of this issue. The title can change based on if it's fulfilled or not.
fulfilled_effect = <float> unfulfilled_effect = <float>	The faction approval impact of this issue.
potential trigger	The former block of Conditions determines should this faction have this issue, and if yes, the later block of Conditions determines is this issue fulfilled. (Faction scope, use owner to scope to the Empire)
on_create	A block of Effects to be executed to the faction when this faction is created. Vanilla always have pop_faction_event = { id = factions.1 }, which calls the event to tell the player "a faction named FaFaFaFaction led by a leader LeLeLeLeader is created". (Faction scope)
on_destroy	A block of Effects to be executed to the Empire when this faction is dissolved. Vanilla always remove the "???ism Ethic Promoted" and "???ism Ethic Supressed" static modifiers for the Empire. (Country scope)
actions	A list of entries to define actions an Empire can take to this faction.
title = <localisation key> description = <localisation key>	The flavor text part of this faction action.
cost = { <resource key> = <int> }	The cost of this faction.
potential valid	The former block of Conditions determines should this faction have this action listed, and if yes, the later block of Conditions determines can this action be performed. (Faction scope)
effect	A block of Effects to be executed when this action is taken. (Faction scope)
ai_weight	How likely the AI will use this action.

Faction Example

Imperialist Faction

imperialist = {
	election_header = "GFX_faction_header_yellow"
	guiding_ethic = ethic_militarist

	unique = yes
	support_multiplier = 1

	resources = {
		category = pop_factions
		produces = {
			influence = 2
		}
	}

	is_potential = {
		years_passed > 10
		has_encountered_other_species = yes
		NOT = { has_ethic = ethic_gestalt_consciousness }
	}

	parameters = {
		empire = {
			type = country
			valid_objects = {
				is_same_value = root
			}
		}
	}

	can_join_pre_triggers = {
		is_enslaved = no
		is_being_purged = no
	}

	can_join_faction = {
		is_shackled_robot = no
		has_culture_shock = no
		NOT = { has_trait = trait_nerve_stapled }
		OR = {
			has_ethic = ethic_militarist
			has_ethic = ethic_fanatic_militarist
		}
	}

	attraction = {
		base = 100

		modifier = {
			factor = 1.25
			exists = from
			from = {
				exists = leader
				leader = { leader_class = ruler }
			}
		}

		modifier = {
			factor = 0.75
			exists = from
			from = {
				NOT = { exists = leader }
			}
		}

		modifier = {
			factor = 1.25
			has_citizenship_rights = yes
		}
	}

	leader = {
		base = 100

		modifier = {
			factor = 0.0
			is_event_leader = yes
		}
	}

	demand = {
		title = "FACTION_OUTRAGED_GC"
		unfulfilled_title = "FACTION_OUTRAGED_GC"
		desc = "FACTION_OUTRAGED_GC_DESC"

		fulfilled_effect = -20
		unfulfilled_effect = -0.001

		potential = {
			exists = owner
			owner = {
				has_country_flag = faction_militarist_outraged_gc
			}
		}

		trigger = {
			owner = {
				has_country_flag = faction_militarist_outraged_gc
			}
		}
	}

	...

	on_create = {
		pop_faction_event = { id = factions.1 }
	}

	on_destroy = {
		if = {
			limit = {
				has_modifier = promoted_militarist
			}
			remove_modifier = promoted_militarist
		}
		if = {
			limit = {
				has_modifier = suppressed_militarist
			}
			remove_modifier = suppressed_militarist
		}
	}

	actions = {
		embrace_faction = {
			title = "EMBRACE_FACTION"
			description = "EMBRACE_FACTION_DESC"

			cost = {
				influence = 500
			}

			potential = {
				exists = owner
				owner = {
					OR = {
						is_subject = no
						NOT = { is_subject_type = dominion }
					}
				}
			}

			valid = {
				custom_tooltip = {
					fail_text = EMBRACE_FACTION_COOLDOWN
					parameter:empire = {
						NOT = { has_modifier = embraced_faction_timer }
					}
				}
				support > 0.20
				parameter:empire = {
					NOT = { has_ethic = "ethic_fanatic_militarist" }
				}
			}

			effect = {
				add_modifier = { modifier = embraced_faction days = 3600 }
				parameter:empire = {
					shift_ethic = ethic_militarist
					hidden_effect = {
						add_modifier = { modifier = embraced_faction_timer days = 3600 }
						every_pop_faction = {
							limit = { NOT = { is_same_value = root } }
							add_modifier = { modifier = embraced_another_faction days = 3600 }
						}
					}
				}
				hidden_effect = {
					save_event_target_as = TargetFaction
					parameter:empire = {
						every_relation = {
							limit = {
								is_ai = no
								is_country_type = default
								has_communications = prev
							}
							country_event = { id = factions.2000 }
						}
					}
				}
			}

			ai_weight = {
				base = 1
				modifier = {
					factor = 0
					support < 0.50
					owner = {
						has_ethic = ethic_militarist
					}
				}
				modifier = {
					factor = 0
					owner = { has_valid_civic = civic_fanatic_purifiers }
				}
				modifier = {
					factor = 0
					NOT = {
						owner = {
							exists = ruler
							ruler = {
								leader_of_faction = imperialist
							}
						}
					}
				}
				modifier = {
					factor = 0
					owner = {
						count_pop_factions = {
							count < 4
						}
					}
				}
			}
		}
		promote_faction = {
			title = "PROMOTE_FACTION"
			description = "PROMOTE_FACTION_DESC"

			potential = {
				exists = owner
				parameter:empire = {
					NOR = {
						has_modifier = suppressed_militarist
						has_modifier = promoted_militarist
					}
				}
			}

			effect = {
				parameter:empire = {
					add_modifier = { modifier = promoted_militarist days = -1 }
				}
			}

			ai_weight = {
				base = 0
			}
		}
		cancel_promote_faction = {
			title = "CANCEL_PROMOTE_FACTION"
			description = "CANCEL_PROMOTE_FACTION_DESC"

			potential = {
				exists = owner
				parameter:empire = { has_modifier = promoted_militarist }
			}

			effect = {
				parameter:empire = {
					remove_modifier = promoted_militarist
				}
			}

			ai_weight = {
				base = 0
			}
		}
		suppress_faction = {
			title = "SUPPRESS_FACTION"
			description = "SUPPRESS_FACTION_DESC"

			potential = {
				exists = owner
				parameter:empire = {
					NOR = {
						has_modifier = suppressed_militarist
						has_modifier = promoted_militarist
					}
				}
			}

			effect = {
				add_modifier = { modifier = suppressed_faction days = -1 }
				parameter:empire = {
					add_modifier = { modifier = suppressed_militarist days = -1 }
				}
			}

			ai_weight = {
				base = 0
			}
		}
		cancel_suppress_faction = {
			title = "CANCEL_SUPPRESS_FACTION"
			description = "CANCEL_SUPPRESS_FACTION_DESC"

			potential = {
				exists = owner
				parameter:empire = { has_modifier = suppressed_militarist }
			}

			effect = {
				remove_modifier = suppressed_faction
				parameter:empire = {
					remove_modifier = suppressed_militarist
				}
			}

			ai_weight = {
				base = 0
			}
		}
	}
}

The AI will only embrace a faction if current ruler is the faction leader. Also,  Fanatic Purifiers will never embrace factions.

Some issues will increase faction approval by +0.001 if fulfilled, or decrease approval by -0.001 if unfulfilled. This is to mark the issue green or red. If an issue currently has no effect, it will be marked yellow, which can be confusing.

Modding

Pops	Jobs • Factions

Leaders

Leaders • Leader Traits

Species

Species • Species Traits

Land Warfare

Armies • Bombardment Stance