mpo_overrunning_vassal_title_distribution_effect

mpo_overrunning_vassal_title_distribution_effect = {
	every_held_title = {
		limit = {
			tier = tier_county
			any_this_title_or_de_jure_above = {
				tier = tier_duchy
				NOT = {
					this = scope:new_capital_duchy
				}
			}
		}
		add_to_list = overrun_counties
	}
	scope:target = {
		every_direct_de_jure_vassal_title = {
			limit = {
				tier = tier_duchy
				NOT = {
					this = scope:new_capital_duchy
				}
				any_de_jure_county = {
					count >= 2
					holder = scope:attacker
				}
				OR = {
					NOT = { exists = holder }
					holder.top_liege = scope:defender
					holder.top_liege = scope:attacker
				}
			}
			add_to_list = overrun_duchies
		}
	}
	#Distribute all counties
	while = {
		limit = {
			any_in_list = {
				list = overrun_counties
				holder = scope:attacker
			}
			any_in_list = {
				list = potential_overrunning_vassals
				NOT = {
					has_character_flag = got_overrun_title
				}
			}
		}
		#Is a duchy available?
		if = {
			limit = {
				any_in_list = {
					list = overrun_duchies
					any_de_jure_county = {
						holder = scope:attacker
					}
				}
			}
			#Grant biggest duchy available
			if = {
				limit = {
					any_in_list = {
						list = overrun_duchies
						#Forgive me for how stupid this is
						any_de_jure_county = {
							count >= 5
							holder = scope:attacker
						}
					}
				}
				random_in_list = {
					list = overrun_duchies
					limit = {
						any_de_jure_county = {
							count >= 5
							holder = scope:attacker
						}
					}
					save_scope_as = duchy_to_grant
				}
			}
			else_if = {
				limit = {
					any_in_list = {
						list = overrun_duchies
						#Forgive me for how stupid this is
						any_de_jure_county = {
							count >= 4
							holder = scope:attacker
						}
					}
				}
				random_in_list = {
					list = overrun_duchies
					limit = {
						any_de_jure_county = {
							count >= 4
							holder = scope:attacker
						}
					}
					save_scope_as = duchy_to_grant
				}
			}
			else_if = {
				limit = {
					any_in_list = {
						list = overrun_duchies
						#Forgive me for how stupid this is
						any_de_jure_county = {
							count >= 3
							holder = scope:attacker
						}
					}
				}
				random_in_list = {
					list = overrun_duchies
					limit = {
						any_de_jure_county = {
							count >= 3
							holder = scope:attacker
						}

As written in game/common/scripted_effects/09_dlc_mpo_scripted_effects.txt.