Superluminal Travel (or Faster than Light travel as it is often referred to) is the method by which individuals or species traverse galactic distances within a relatively short amount of time using specialised engine drives. Crossing these immense distances is achieved by accessing the Cosmic Plane, which is a multidimensional realm existing in cohesion with the Convergence Multiverse.
The Cosmic Plane is a, hidden multi-dimensional realm of space that is existent across the entire Convergence Multiverse. The plane is composed of pure, volatile white Cosmic Energy and is virtually inaccessible to most civilisations, except those that have reached the highest levels of technological sophistication. The existence of this realm allows for the Convergence Multiverse to thrive without fading away or violently collapsing. Unlike normal space that has three dimensions, the Cosmic Plane has far more, which effectively makes it impossible to see or perceive in any way.
The existence of the Cosmic Plane allows for the continued thriving existence of normal space. However this is not the only realm that is reliant on the Cosmic Plane to exist. As a direct result of the Cosmic Plane's existence, another multidimensional realm exists layered underneath normal space. This alternate space acts as a barrier between the normal and Cosmic planes. It's proximity to the Cosmic Plane causes it to take on some of its properties due to a reality warping effect exerted on it. As such, this multidimensional "Warp Space" can be used to traverse vast distances over relatively lesser amounts of time.
Because it isn't composed of cosmic energy, nor as much deeply layered away beneath the fabric of space as the Cosmic Plane is, Warp Space is more easily accessible to civilisations that have managed to produce even the most rudimentary forms of FTL. The basic method through which this is achieved is by producing a drive that is capable of tearing a micro blackhole-like singularity in the fabric of space and producing a method through which the ship is able to "squeeze" through it. A common method to enable the ship to transition through this singularity is by having the drive generate a quantum field around the ship to protect it from direct exposure to Warp Space.
The harsh environment of Warp Space is due to the fact that its multidimensional nature could effectively tear ships or living beings to pieces by displacing their atoms across space and in some instances, time. As such, these quantum fields are essential to translate the ship's presence to the multidimensional realm of Warp Space without affecting the vessel inside the field. Due to the Warp Space's proximity to the Cosmic Realm, unguided vessels can inadvertently by thrown into the Cosmic Plane where even the most sophisticated energy shielding would not be able to protect the ship from complete and utter vaporisation.
As such, it is essential that the ship's computers run constant calculations to maintain the quantum field around itself and guide the ship through the foreign environment of Warp Space in order for the vessel to safely reach it's destination.
Levels of Technological Advancement
This type is for civilisations who have just discovered FTL drives. The technology is rudimentary, but it gets the job done. The drive allows for spacecraft to safely transition between normal and Warp Space without the craft being torn apart and vaporised by the alternate realm’s harsh environment. Travel between star systems in the same sector can take days to weeks while travel to other sectors, especially those across the galaxy can take up to months to accomplish. Jumps are not always pinpoint accurate either, with spaceships possibly ending up a few kilometers away from the intended destination.
Civilisations who have been space-faring for many years now are likely to have produced more advanced FTL drives. These engines enable spacecraft to traverse systems in the same sector within a few minutes to hours while travel to other sectors, especially those across the galaxy could take up to a few days to weeks at most. Warp Space jumps are a lot more accurate.
Only very few civilisations would be able to reach this stage, and in doing so it would take a long time. Travel to virtually anywhere in the galaxy is relatively instantaneous. Destination arrivals are pinpoint accurate. Civilisations who achieve this speed of travel often set their sights outside their galaxy and begin to travel to and explore other galaxies within their galactic neighbourhood. Depending on the distance between the home and destination galaxies, traversing between these two points can take from a few months to several years due to the comparatively larger amount of space crossed.
Civilisations at this point can only attempt to advance further and lessen the time taken to travel between galaxies, however improving an already incredibly sophisticated piece of technology can only go so far and most factions or species would find themselves unable to progress beyond this point.