Shield of Humanity, a new rules supplement for Only War includes rules for playing characters attached to the Imperial Guard who hail from the two most important religious institutions in the Imperium: the Adeptus Mechanicus, and the Adeptus Ministorum, as well as characters belonging to either of the Abhuman sub-species that fight with the front ranks of the Imperial Guard. In addition, Shield of Humanity also includes a host of new rules for creating new regiments. New Home Worlds and new Doctrines give Players and Game Masters all the options they need to create their own unique regiments.