Half Plate Armors is a type of armor consisting of a breastplate, backplate, and shoulder plates, worn over a padded underlayer. It provides protection to the upper body while allowing for greater mobility compared to full plate armor.
Heavy armor can be upgraded to the next tier up for the difference in cost. For example, a blacksmith can upgrade a Cuirass Armors to a suit of half plate for a cost of 360 gp