tournament_contest_team_composition_effect

tournament_contest_team_composition_effect = {
	scope:activity = {
		set_variable = { name = tournament_commenced }
		# Players
		every_guest_subset = {
			name = contestant
			phase = tournament_phase_$CONTEST$
			limit = {
				OR = {
					is_ai = no
					AND = {
						has_court_position = champion_court_position
						liege = { is_ai = no }
					}
				}
				tournament_contest_can_compete_trigger = yes
				var:progress_to_victory >= scope:activity.var:progress_to_victory_threshold
			}
			add_tournament_contest_contestant_effect = {
				CONTEST = $CONTEST$
				SKILL = $SKILL$
				PTV = progress_to_victory_active_contestant_value
			}
		}
		# Filter relevant into entrants list
		while = {
			limit = {
				any_guest_subset = {
					name = qualified
					phase = tournament_phase_$CONTEST$
					count < 20
				}
				any_guest_subset = {
					name = contestant
					phase = tournament_phase_$CONTEST$
					tournament_contest_can_compete_trigger = yes
				}
			}
			# Determine eligible contestants
			ordered_guest_subset = {
				name = contestant
				phase = tournament_phase_$CONTEST$
				limit = { tournament_contest_can_compete_trigger = yes }
				order_by = var:progress_to_victory
				add_tournament_contest_contestant_effect = {
					CONTEST = $CONTEST$
					SKILL = $SKILL$
					PTV = progress_to_victory_active_contestant_value
				}
			}
		}
		# Inform liege of prestige from qualified knights
		tournament_liege_qualification_toast_effect = yes
		# Pick first team alpha character
		random_guest_subset = {
			name = qualified
			phase = tournament_phase_$CONTEST$
			limit = { this = scope:host }
			alternative_limit = {
				has_court_position = champion_court_position
				liege = scope:host
			}
			alternative_limit = { is_playable_character = yes }
			alternative_limit = { always = yes }
			save_scope_as = new_list_member
			scope:activity = {
				add_to_guest_subset = {
					name = team_alpha
					target = scope:new_list_member
					phase = tournament_phase_$CONTEST$
				}
			}
			save_scope_as = team_alpha_creator
		}
		# Pick first team beta character
		random_guest_subset = {
			name = qualified
			phase = tournament_phase_$CONTEST$
			limit = {
				is_playable_character = yes
				has_any_bad_relationship_with_character_trigger = { CHARACTER = scope:team_alpha_creator }
				this != scope:team_alpha_creator
			}
			alternative_limit = {
				is_playable_character = yes
				this != scope:team_alpha_creator
			}
			alternative_limit = {
				this != scope:team_alpha_creator
			}
			weight = {
				base = 1
				modifier = {
					factor = 10
					has_any_bad_relationship_with_character_trigger = { CHARACTER = scope:team_alpha_creator }
				}
				modifier = {
					factor = 10
					AND = {
						scope:team_alpha_creator = { has_activity_intent = murder_attendee_intent }
						this = scope:team_alpha_creator.intent_target
					}
				}
				modifier = {
					factor = 0.5
					liege = scope:team_alpha_creator
				}
				modifier = {
					add = 1
					top_liege = this
				}
				modifier = {
					add = 1
					primary_title.tier >= scope:team_alpha_creator.primary_title.tier
				}
			}
			save_scope_as = new_list_member
			scope:activity = {
				add_to_guest_subset = {
					name = team_beta

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