Due to the powerful exo-skeleton and power sources built into their armour, characters in Terminator armour are capable of moving and firing with heavy weapons. On the other hand, models in Terminator armour that win a close combat may only consolidate; they will not be able to advance. A model wearing Terminator armour has a 2+ Armour save and a 5+ Invulnerable save. Having been trained to use these suits to their full potential, Grey Knights in Terminator armour (but not Inquisitors) have one more Attack on their profile than normal. Also, any model wearing Terminator armour can be teleported onto the battlefield, and set up using the Deep Strike rules, but only if the mission allows for Deep Strike to be used. If the mission does not allow units to use the Deep Strike rules then the model must set up normally with the rest of the army.
Errata — Chapter Approved: Codex: Daemonhunters Q&A (v1.0): Terminator and Artificer armour are not upgrades to Power armour — a model may buy either directly, without first buying Power armour. If a Grey Knights character is given Artificer armour or Power armour instead of Terminator armour, he does not lose the extra Attack normally associated with Terminator armour: that Attack comes from the character's Veteran status, not the armour itself, so he keeps it regardless of which armour he wears.