Warp Travel, by The-First-Magelord
The Warhammer 40K version of Warp Travel, by The-First-Magelord. In contrast to science fiction settings like Star Trek and Star Wars, where FTL is simply a handwavium plot device for getting from A to B, Warhammer 40K paints a bleak and pessimistic universe in which FTL travel literally means traversing hell. In my own universe, FTL dimensions such as paraspace are not actually malevolent, but has a chaotic, psychedelic quality. Hence is someone is havuing a “bad trip”, paraspace may actually look like this

As the second of the major zones through which ships travel faster than light (ftl), paraspace is intermediate between hyperspace and aetherspace.

Because it is often nonlocal and acausal, paraspace allows hypertransit between remote points in space (ftl), time (time travel), from one spacetime universe to another (slidestepping, via hyperspace or hypertime dimensions), or from an empirical physical universe to an imaginal one (portalling, traversing ontological degrees or zone). Transit from realspace and hyperspace to paraspace and back again is always acausal, paradoxical, and against the laws of physics, but some regions of spacetime, called jumppoints (or portals or stargates), allow low paradoxigenic access and egress.

To avoid becoming lost, ships follow specific paths (paraspace conduits) defined by logic beacons and the impressions (samskaras) of previous vessels. As paraspace transit can be hazardous to the sanity of realspace sophonts, ships use Leery reality field devices to maintain empiric (rational) conditions on board, and passengers are generally advised to spend travel time in a controlled hybernation state (sleepers). Many travellers however prefer to remain awake, or deliberately pursue psychophanic experiences (trippers). Paraspace includes various zones and dimensions, which are categorised from a mundane perspective as being near physical (closer to and more similar to realspace) or far parapsace (further away and more dissimilar).