tournament_pivotal_contestant_scope_effect

tournament_pivotal_contestant_scope_effect = {
	if = {
		limit = {
			has_none_of_variables = {
				name = resigned_contest_flag
				name = disqualified_contest_flag
			}
			trigger_if = {
				limit = {
					scope:activity = {
						activity_tournament_versus_contest_trigger = yes
						var:contest_versus_progress ?= 2
					}
				}
				is_in_guest_subset = { name = finalist }
			}
			trigger_else_if = {
				limit = {
					scope:activity = {
						activity_tournament_versus_contest_trigger = yes
						var:contest_versus_progress ?= 1
					}
				}
				is_in_guest_subset = { name = semi_finalist }
			}
			trigger_else = {
				is_in_guest_subset = { name = qualified }
			}
		}
		save_scope_as = pivotal_contestant
	}
	# Otherwise, find someone you care about to frame the event
	else = {
		# Filter out anyone who is no longer a valid contestant
		scope:activity = {
			every_guest_subset_current_phase = {
				name = qualified
				limit = {
					has_none_of_variables = {
						name = resigned_contest_flag
						name = disqualified_contest_flag
					}
					trigger_if = {
						limit = { scope:activity.var:contest_versus_progress ?= 2 }
						is_in_guest_subset = { name = finalist }
					}
					trigger_else_if = {
						limit = { scope:activity.var:contest_versus_progress ?= 1 }
						is_in_guest_subset = { name = semi_finalist }
					}
					trigger_else = { always = yes }
					this != root
				}
				add_to_list = potential_pivotal_contestants
			}
		}
		# Randomly select the most relevant character possible
		random_in_list = {
			list = potential_pivotal_contestants
			# Intent Targets
			limit = { root.intent_target ?= this }
			# Wager Targets
			alternative_limit = { root.var:tournament_wager_target ?= this }
			# Relations
			alternative_limit = { has_relation_to = root }
			# Champions
			alternative_limit = { root.court_position:champion_court_position ?= this }
			# Children
			alternative_limit = { is_child_of = root }
			# Spouses
			alternative_limit = { is_consort_of = root }
			# Close Family
			alternative_limit = { is_close_family_of = root }
			# Liege
			alternative_limit = { root.liege ?= this }
			# Powerful Vassals
			alternative_limit = { is_powerful_vassal_of = root }
			# Vassals
			alternative_limit = { is_vassal_of = root }
			# Knights
			alternative_limit = { is_knight_of = root }
			# Extended Family
			alternative_limit = { is_extended_family_of = root }
			# Courtiers
			alternative_limit = { is_courtier_of = root }
			# Other
			alternative_limit = { always = yes }
			weight = {
				base = 1
				opinion_modifier = {
					who = root
					opinion_target = this
				}
				modifier = { add = var:progress_to_victory }
			}
			save_scope_as = pivotal_contestant
		}
	}
	if = {
		limit = {
			exists = scope:contest_winner
			exists = scope:contest_loser
		}
		if = {
			limit = { scope:pivotal_contestant = scope:contest_winner }
			scope:contest_loser = { save_scope_as = other_contestant }
		}
		else = {
			scope:contest_winner = { save_scope_as = other_contestant }
		}
	}
}

As written in game/common/scripted_effects/04_dlc_ep2_tournament_effects.txt.