10 Sekunden Google sagt, dass dein Script unvollständig ist. Hier ist das Ganze:
Code:
#  -------------------------------------------------
#  Script Name : Play Movie before skill
#  Scripter : efeberk
#  Date : 29.07.2013 07:28
#  Version : RPG Maker VX Ace(RGSS3)
#  ------------------------------------------------
#
#  How to:
#   
#  Just add a little text to skill notetag
#
#  <movie: x>
#
#  x = movie name
#

class RPG::Skill < RPG::UsableItem
  
  def movie
    @note.scan(/<(?:MOVIE|movie):\s(\w+)>/i)
    return $1.to_s
  end
  
end

class Game_Battler < Game_BattlerBase
  
  def use_item(item)
    if item.is_a?(RPG::Skill)
      Graphics.play_movie('Movies/' + item.movie) unless item.movie.empty?
      pay_skill_cost(item)
    end
    consume_item(item)   if item.is_a?(RPG::Item)
    item.effects.each {|effect| item_global_effect_apply(effect) }
  end
end