CK3 DatabaseCrusader Kings III · 1.20.0.3 “Crozier” · unofficial

Casus belli · Event wars

Invasion

Invasion is a casus belli in Crusader Kings III (event wars). If the attacker wins: The attacker seizes all of the defender's titles within the target kingdom. If the defender wins: The defender keeps their titles. The attacker loses Prestige and pays reparations to the defender. The war goal is worth 80% war score. Patch 1.20.0.3, from game/common/casus_belli_types/00_event_war.txt.

Quick answers (2)
What do you get for winning a Invasion war in CK3?
The attacker seizes all of the defender's titles within the target kingdom (patch 1.20.0.3).
What happens on a white peace?
The defender keeps their titles. The attacker loses Prestige.

How the war ends

Attacker wins

The attacker seizes all of the defender's titles within the target kingdom.

White peace

The defender keeps their titles. The attacker loses Prestige.

Defender wins

The defender keeps their titles. The attacker loses Prestige and pays reparations to the defender.

If the war becomes invalid

The … has ended: the defender no longer … any land in the target region.

Who can declare it

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

Every event wars 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.

Defender (allowed_against_character) (6 lines of game script)
scope:attacker = {
	ALL_FALSE = {
		top_liege = scope:defender.top_liege
		liege = scope:defender
	}
}

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

When it can start (valid_to_start) (1 line of game script)
always = no

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

Source: game/common/casus_belli_types/00_event_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.