CK3 DatabaseCrusader Kings III · 1.20.0.3 “Crozier” · unofficial

Casus belli · Event wars

Diarch Seizure

Diarch Seizure is a casus belli in Crusader Kings III (event wars). If the attacker wins: The defender surrenders all Titles and Vassals that De Jure belong to the attacker. If the defender wins: The defender loses nothing to the attacker. 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 Diarch Seizure war in CK3?
The defender surrenders all Titles and Vassals that De Jure belong to the attacker (patch 1.20.0.3).
What happens on a white peace?
The defender loses nothing to the attacker.

How the war ends

Attacker wins

The defender surrenders all Titles and Vassals that De Jure belong to the attacker

White peace

The defender loses nothing to the attacker.

Defender wins

The defender loses nothing to the attacker.

If the war becomes invalid

The … has ended: the defender can no longer be vassalized.

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.

Attacker (allowed_for_character) (1 line of game script)
always = yes

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.