   Wearable Armor and Clothing
  I am working on an RPG, and I was thinking of adding wearable armor and equipment to my game so that anything the player has equipt will be "worn" on the character model. Doing weapons is easy: just attach the weapon or shield to the player character's hand bone via matrix multiplcation, but what about armor that will encase the entire body of the character? I was thinking of giving the armor such as the chestplates the same skeletal system, and whenever the player character's body had an animation, or set of animations being applied to it, I would apply the same animation to the armor set so that the armor would flex and move according to the character animations. However, then I have the problem of having characters with different body builds. I would need this armor to fit bigger characters and smaller characters.Also, performance may be way too much to do on a mobile platform though! Are there any more efficient ways of doing this than the one I specified above?   
  you could do it wow style :not every item has a model. infact some specific items such as chest armors and boots are simply textures that appear in the area of the item. an item has diffrent sets of transformation matrices for each race in wow(making it one geometry and 10 sets of matrices per item). unless the player is able to dynamicly change their character's size,that shouldn't be a problem.;  I think your asking for trouble trying to make a set of armor the same shape as the character model and moving them together. I think the norm is to have a different character model or different texture for each armor and render add on parts like swords and shields just as you are now.