class Creature
    def self.metaclass
        class << self; self; end
    end

    def self.traits(*arr)
        return @traits if arr.empty?
        attr_accessor(*arr)

        arr.each do |a|
            metaclass.instance_eval {
                define_method(a) do |val|
                  return @traits[a] if val.nil?
                  @traits ||= {}
                  @traits[a] = val
                end
            }
        end

        class_eval do
            define_method( :initialize ) do
                self.class.traits.each do |k,v|
                    instance_variable_set("@#{k}", v)
                end
            end
        end
    end


    traits :life, :strength, :charisma, :weapon
end


class Dragon < Creature
    life 100
    strength 200
    charisma 1
    weapon 1000
end
Dragon.life