class Game_Actor

  # 仅为示例，请勿模仿！
  def <=> other
    return unless other.respond_to? :name
    name <=> other.name
  end
end

$game_party.actors.sort  # 角色都按照名字排序了


case actor_id
when Float
  "ID是小数"
when 1, 2
  "主角"
when 3..8
  "酱油"
when lambda { |id| id.even? }
  "ID是偶数"
else
  ""
end