Hallows and Hollows are the two main types of mechs in the Divine Principality. Both types are often humanoid in shape, and serve as the backbone of Principality military units.
Hallows are mechs blessed (hallowed) by a Divine. This may grant them special abilities in battle, and gives their pilots enough social prestige that they are held above ordinary citizens. They are usually special models or prototypes made custom for a single pilot; many are made by the Zenith Fund.
A mech that has not been blessed is a Hollow. These are usually mass produced, commonly being standard AdArm or Zenith Fund models.