scheme_change_movement_power_effect

scheme_change_movement_power_effect = {
	save_scope_value_as = {
		name = movement_power_scheme_effect_value
		value = {
			value = $VALUE$
			multiply = 100
		}
	}
	if = {
		limit = {
			scope:movement_power_scheme_effect_value >= 0
		}
		if = {
			limit = {
				exists = var:movement_power_increased_scheme
			}
			set_variable = {
				name = movement_power_increased_scheme
				value = {
					value = var:movement_power_increased_scheme
					add = $VALUE$
				}
			}
		}
		else = {
			set_variable = {
				name = movement_power_increased_scheme
				value = $VALUE$
			}
		}
	}
	else = {
		if = {
			limit = {
				exists = var:movement_power_decreased_scheme
			}
			set_variable = {
				name = movement_power_decreased_scheme
				value = {
					value = var:movement_power_decreased_scheme
					add = $VALUE$
				}
			}
		}
		else = {
			set_variable = {
				name = movement_power_decreased_scheme
				value = $VALUE$
			}
		}
	}
	#force the update of variables to immediately show changes
	if = { #for characters
		limit = {
			exists = var:movement_power_individual
		}
		if = {
			limit = {
				scope:movement_power_scheme_effect_value >= 0
			}
			custom_tooltip = movement_power_scheme.tt.increased_character
		}
		else = {
			custom_tooltip = movement_power_scheme.tt.decreased_character
		}
		update_character_movement_power_effect = yes
		top_participant_group:dynastic_cycle ?= {
			update_movement_power_effect = yes
		}
	}
	else = { #for movements
		if = {
			limit = {
				scope:movement_power_scheme_effect_value >= 0
			}
			custom_tooltip = movement_power_scheme.tt.increased_movement
		}
		else = {
			custom_tooltip = movement_power_scheme.tt.decreased_movement
		}
		update_movement_power_effect = yes
	}
}

As written in game/common/scripted_effects/10_dlc_tgp_scripted_effects.txt.