Casus belli · Civil wars and factions

Rebellion

Rebellion is a casus belli in Crusader Kings III (civil wars and factions). If the attacker wins: Rebelling Counties will take De Jure Duchies and become independent realms with each attacker as its ruler. If the defender wins: Rebelling Counties and Vassals remain part of the realm. All rebelling Vassals are Imprisoned by the defender. The war goal is worth 80% war score. Patch 1.20.0.3, from game/common/casus_belli_types/00_civil_war.txt.

Quick answers (2)

What do you get for winning a Rebellion war in CK3?: Rebelling Counties will take De Jure Duchies and become independent realms with each attacker as its ruler (patch 1.20.0.3).
What happens on a white peace?: Rebelling Counties and Vassals remain part of the realm.

How the war ends

Attacker wins

Rebelling Counties will take De Jure Duchies and become independent realms with each attacker as its ruler.

White peace

Rebelling Counties and Vassals remain part of the realm.

Defender wins

Rebelling Counties and Vassals remain part of the realm. All rebelling Vassals are Imprisoned by the defender.

If the war becomes invalid

The … has ended: it was no longer valid to continue.

Who can declare it

The game shows no text of its own for these conditions; the script is below.

Every civil wars and factions war (the group's allowed_for_character) (1 line of game script)

herders_and_tributary_constraints = yes

As written in game/common/casus_belli_groups/00_casus_belli_groups.txt.

Attacker (allowed_for_character) (6 lines of game script)

scope:attacker = {
	OR = {
		is_leading_faction_type = populist_faction
		is_leading_faction_type = escalated_peasant_faction
	}
}

As written in game/common/casus_belli_types/00_civil_war.txt.

Source: game/common/casus_belli_types/00_civil_war.txt and the English localisation, Crusader Kings III 1.20.0.3. “The attacker”, “the defender” stand where the game names the character; “…” marks other words it fills in during play.