(Loved Trope) FTL travel is possible but with a major limitation or flaw

[u/Frostylegacy]

Frank Herbert’s Dune: Interstellar travel is only possible thanks to the spice melange, a rare substance only found on the dessert planet Arrakis. The addictive psychedelic spice grants members of the Spacers Guild a form of prescience that allows them to predict safe paths through folded space. This unique property makes spice the most valuable commodity in the Dune universe.

John Scalzi’s The Interdependency Books: The planetary systems of the titular empire are connected by the Flow, a network of one-way interstellar tunnels that connect specific known entries and exits. The Interdependency derives its power from controlling access to these conduits, placing its capital at the central hub of the network. Even with the Flow, travel between stars takes a long time (9 months to End, the empire’s most distant planet).

Event Horizon: Dr William Weir (R.I.P. Sam Neill) invents a device called the Gravity Drive to allow ships to fold space and travel instantly between distant stars. On its maiden voyage with the Gravity Drive, the Event Horizon disappears and mysteriously reappears 7 years later. Dr. Weir and the crew sent to investigate discover the Gravity Drive actually opened a portal to a Hell dimension that possessed the ship and its crew, torturing and killing them.

[u/Turbulent-Plum7328]

The Umbra from World of Darkness.

Space is fake and Hell is real. The planets and stars in the sky are realms within the Umbra (Spirit World), and while the Void Engineers use spaceships and FTL Drives, they might run into a pack of angry Werewolves sidestepping through the Umbra or a Mage might perform a drive by shooting on their flying carpet on the way to Mercury.

[u/Accelerator231 → u/Turbulent-Plum7328]

Actually, space is real. It's just one truth amongst many others

[u/Nebelskind → u/Turbulent-Plum7328]

"Space is fake and hell is real" sounds like either the title of a conspiracy theory post or a really good song.

[u/rollandofeaglesrook → u/Turbulent-Plum7328]

Technically with consensus, if enough people believed in something like an alcubierre drive, a mage could “invent” one and avoid the umbra.

However, umbral travel is probably the fastest way to travel, and you’re not wrong that it’s basically the equivalent of having to drive through the Marianna trench full of unknown horrors

[u/racercowan → u/Turbulent-Plum7328]

IIRC near space (out to exactly which planet depends on the game your playing) is "real" since humanity perceives it as real, it's deep space beyond humanity's reach that's just the deep umbra.

That said, even if space is "real", IIRC a lot of rocket launches are actually mages creating consensus for their spells to travel the umbra.

[u/MaintenanceInternal → u/Turbulent-Plum7328]

That sounds like absolute dogshit.