Editing Gellar Field (section)

== The Warp, Giant Space Cathedrals and You ==
The TL:DR explanation to warp travel is to think of it as a submarine voyage, only instead of water that pours in when a leak springs, it's hordes of demons that want to kill you, mutate you, infect you and/or rape you.

As for a more detailed explanation, it's been mentioned a few times in the fluff that while the Gellar field on Imperial ships most definitely has a mechanical component, the field is reinforced by all the giant statues and gold bling that the humans of the setting feel the need to shove on every square inch of the hull. It actually makes a kind of sense when you think about it: The warp is a realm governed not by boring old logic but rather the thoughts and feelings of everyone in real space. Since Imperial ships are already borderline worshipped by humans as the physical manifestation of humanity's might and manifest destiny to rule the stars, turning them into ''actual'' space borne cathedrals (I.E. places of worship) could have an effect similar to the old belief that demons can't enter holy ground. Typically, this works pretty well as the greatest threat to an Imperial ship whose Gellar Field fails is the Warp itself, not the daemons.  Daemonic incursions aboard are rare but not rare enough and the crew often manages to fight off the invaders either until they reach their destination or until they can safely drop out of the Warp.  This ability to hold their ground likely is solely due to their faith and the holy ground thing.  Notice that Imperial ships during the Great Crusade who suffered a daemonic invasion were unheard of.  As in, never heard from again.  Because atheism is a bad idea against enemies dominated by belief.