armor.rb

class Armor < ActiveRecord::Base
  attr_accessible :back_id, :character_id, :chest_id, :feet_id, :hands_id, :head_id, :legs_id, :shoulder_id, :waist_id, :finger_id
  belongs_to :character
  
  [:back, :chest, :feet, :hands, :head, :legs, :shoulder, :waist, :finger].each do |part|
    belongs_to part, :class_name => 'ArmorItem'
  end
  
end

armor_item.rb

class ArmorItem < ActiveRecord::Base
  attr_accessible :armor_tier_id, :bonus_id, :enchant_id, :name, :stat_set_id
  
  belongs_to :armor_tier
  belongs_to :enchant
  belongs_to :bonus
  belongs_to :stat_set
  
  def stat
    StatSet.find(stat_set_id)
  end
  
  [:agility, :stamina, :strength, :intellect].each do |stat|
    define_method stat do
      armor_tier.stat.send(stat) + stat_set.send(stat)
    end
  end
  
end

armor_material.rb

class ArmorMaterial < ActiveRecord::Base
  attr_accessible :name
  has_many :armor_tiers
end

armor_tier.rb

class ArmorTier < ActiveRecord::Base
  attr_accessible :level, :name, :deviation, :stat_set_id, :armor_material_id
  belongs_to :armor_material  
  belongs_to :stat_set
  
  attr_reader :stat
  
  def stat
    StatSet.find(stat_set_id)
  end
end

bonus.rb

class Bonus < ActiveRecord::Base
  attr_accessible :name
  has_many :stat_set
end

character.rb

class Character < ActiveRecord::Base
  attr_accessible :level, :name
  belongs_to :order
  belongs_to :user
  has_one :armor
  
  [:agility, :stamina, :strength, :intellect].each do |stat|
    define_method stat do
      armor_tier.stat.stat) + stat_set.send(stat)
      (level.to_f * order.send(stat)).round
    end
  end
  
  def health
    ((level.to_f * 10) + (order.stamina * level.to_f)).round
  end
  
end