2w ago

How does FTL or fast travel work in your setting?

I'm especially curious in the case of fantasy settings. I'm admittedly not super well read in the genre, I know about the Ways from the Wheel of Time series[^1] , and I'm sure D&D has its fair share of fast travel mechanics.

Anyway, in my case I use mass routers. Rather than a dry lore dump here's a slightly less dry lore dump in story form!

[^1]: fun fact: the Ways inspired the Nether from Minecraft insofar as one step in one dimension is multiplied in the overworld

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I like settings where FTL doesn't exist, and interstellar travel times are dealt with by simply making humans biologically immortal. If you think about it, curing aging is actually much less of a stretch than FTL, scientifically speaking.
- Check out the new Exodus TTRPG system, it is built around this idea. The companion book by Peter F. Hamilton is also very good, and gives lots of good material to work off of.
So this is more SciFi but the fundementals work for fantasy.
Gates, and gates only so the first time someone has to slowboat it which is either an epic lifetime journey or a sacrifice of your place in time to relativistic travel depending on the genre in order to set up a gate at the destination. The gates then function as a classic folding of space between them, not to zero but such that a multi-lightyear trip is reduced down to an internal length of just a few miles.
This is all fine when everything works, though if the gate shuts off mid transit you can end up with a whole fleet trapped in the intervening void until its turned back on, or worse a nefarious actor who gains control of a pair of gates may even expand the intervening space rather than shrinking it, trapping their victims not just in deep space, but in an ever expanding volume that can't be escaped even with near light-speed travel.
- Has anybody looked at using automated transport and power-up ships to set up the gates? Or is it a process that is sufficiently complex that it can't be carried out by an automated system?
  ...conversely, if your explorer ship is bringing a gate with it, can you turn on the gate mid-trip and rotate crews in and out by passing them back through the gate?
  
  Setting up gates needs exceedingy comlex calibration to account for all the intervening gravitational anonomlies, you could still do it for crew rotation with a lot of effort though the power requirements for actually running a gate, let alone all the test fire to get it calibrated in the first place just for this one crew rotation would put that firmly in 'not in the budget' territory. The normal procedure is more like a colony mission with the crew at the end having to spend several years to set up infastructure at the other end to make the gate opperational. On the bright side one trip pretty much sets you up for life in terms of payment.
Not currently running anything sci-fi, but have been tossing around this idea. Humans die and they lose a tiny amount of weight when they do. Turns out that it is a soul and that soul can be converted into an immense amount of energy for a very short period of time. Destroying the soul in the process. That energy is used to generate a temporary wormhole between space points. However, the soul has influence on the destination so you need someone who wants to die for you. Or you risk your destination not being correct, or worse getting lost in terrible outer dimensions.
Traveller has a very good fully fleshed out system that invokes "jump space" - effectively hyperspace. You leave the primary universe, enter a pocket space, then "precipitate" back into regular space. The duration of the jump is fixed at 1 week no matter the distance. During the week, there is no interaction with regular space. The ship is isolated. It makes for excellent plot mechanics.
In his book about writing sci-fi and fantasy, Orson Scott Card posits this is the first thing you should think about when mai ng your sci-fi setting: FTL (star wars) or Cryogenization (alien). This directly impacts how societies evolve: do you say goodbye to your loved ones when hopping on the starship, knowing you'll never see them again, or can you zap from one side of the galaxy to the other and still be back for breakfast?
- Interesting. Some relevant tidbits my story didn't mention:
  The yinrih are capable of STL interstellar travel, but because they can't lose consciousness without dying, they can't resort to hypersleep. Instead, they use a technique called metabolic suspension which halts metabolism but uses Science™ to keep the brain and nervous system active. The device that does this is called a suspension capsule (referenced in the story above). The traveler is completely submerged in a fluid matrix called neurogel that acts as a non-invasive brain-computer interface, a liquid ventilation medium (for when your metabolism starts up again but your lungs are still paralyzed), and a shock absorbent.
  Since the person is still conscious but their sensory systems don't work, the suspension capsule presents a simulacrum to the traveler in order to keep them from going insane due to lack of sensory input. It also speeds up their subjective time perception to make the trip pass more quickly. The problem with the simulacrum (sim for short) is that the more realistic it is, the more the person is tempted to dissociate, thinking the sim is reality and forgetting their life outside. In order to stave off this madness, Claravian missionaries (the only group to engage in interstellar travel) undertake a rigorous routine of prayer and meditation to keep their minds anchored in reality.
  I needn't tell you that the ability to present an arbitrarily realistic simulation to a person is subject to flagrant abuse, and so-called gel-head parlors offer recreational suspension for a price. This abuse prompts Claravian research monasteries to start looking into safer modes of interstellar travel, which is what results in the invention of the mass router.
  As for the router itself, there are strict mass and volume limits to what can be sent through the underlay, meaning individual flows are limited to a single person and maybe a small carry-on. Because the mass router is discovered while a team of missionaries is living among humans on Earth, a mass router trunk is able to be established between Sol and Focus immediately. The missionaries construct a working mass router using their ship's fabricator and materials found on Earth.
From the sci-fi setting, it's your pretty standard "bend space until both destination and departure points are actually nominally close to each other" kind of drive.
Time between jumps usually bottoms out at around 15-20 minutes for most drives, but increases exponentially as a function of distance traveled and desired accuracy of your destination point.
This is because the pre-calculation to compute a successful bend in space-time grows massively more complex the more gravity fields are involved. Extremely long-distance jumps can take hours or days to calculate, but inter-system jumps can be carried out rapidly.
Intersecting the event horizon of a fold in progress is bad. "You're reduced to a fine relativistic spray" bad. So far accidents have been "minor", as in they didn't kill thousands.
The exotic matter required for drives is stupendously expensive. As a result, almost no ships have internal drives, but require a "drive barge" or "FTL barge" to exploit FTL. Despite this, barges are common enough that most families can afford to take an FTL trip if needed.
In UNHA operations, all drives are legally owned by the government and crewed by a detachment of naval personnel, with explicit orders to scuttle a drive rather than allow it to be misused.
In the fantasy setting, it's a little bit different. For one thing, no two fast travel castings work entirely alike. This is because it is a key tenet that magic is a deeply and intrinsically personal thing, and while casters than study concepts to gain inspiration, there's no such thing as a "standardized" casting which can be moved between casters.
For instance, some casters port you through an alternate dimension, and some bend space. Some open a gateway, some transmute you into photons then back, and some encapsulate you in a bubble which moves rapidly.
Even within a broad category, there are subsets: For instance, if they use an alternate dimension, is it one in which points are simply "closer together", or where time flows differently?
It's important to know these things, because different species or other casters being brought along can have... unexpected reactions to different methods.
- The exotic matter required for drives is stupendously expensive. As a result, almost no ships have internal drives, but require a “drive barge” or “FTL barge” to exploit FTL. Despite this, barges are common enough that most families can afford to take an FTL trip if needed.
  Like a tugboat or tow plane with a glider. Unique.
  In UNHA operations, all drives are legally owned by the government and crewed by a detachment of naval personnel, with explicit orders to scuttle a drive rather than allow it to be misused.
  What constitutes "misuse"?
  Another thing about mass routers, really more about the Underlay, is that you need tailstone for FTL communication, which the mass routing protocol needs to form neighbor relationships with adjacent routers. Tailstone is manufactured by growing monocrystals and fractioning them into wafers. A tailstone wafer can only communicate with other wafers shaved from the same monocrystal, so Underlay tunnel interface cards are sold in sets (usually pairs) that are hard-linked to one another, containing matching wafers. The ansible links between nodes are therefor much more like hard wire runs in that they can't be easily changed to different endpoints.
  This manufacturing process has a lot of cybersecurity implications. A bad actor planted within a tailstone fab could grow larger crystals than a downstream client ordered, then break the crystals up to form multiple normal sized ones, giving the client the expected quantity and keeping the other half. That bad actor could then perform MITM attacks on ansibles or routers using those crystals.
  One such attack is route poisoning, which is where a malicious router injects false routes into the system, telling other routers that a particular endpoint is somewhere it isn't, redirecting travelers to a destination of the attacker's choosing.
  Refreshing that the defining characteristic of your magic system seems to be that it isn't a system.
  It’s important to know these things, because different species or other casters being brought along can have… unexpected reactions to different methods.
  I love the trope of fast travel being inherently scary. One idea I had was an inversion of the typical hyperspace is hell concept whereby FTL shunted you through Heaven, the risk wasn't demonic possession but having your face melted off by overwhelming holiness Raiders of the Lost Ark style, meaning special precautions had to be taken to keep people from perceiving the environment outside the ship, even conceptually (via sensor readings, for example).
  As for the Lonely Galaxy, there are rumors among the superstitious that the Underlay is in fact the Void (the Claravian version of hell), and that the reason why the Bright Way discourages even negative discussion of demons is that it would make them look bad if the network they invented was routed through the realm of the damned.
  
  What constitutes "misuse"?
  The big fears are trying to use one as a weapon is the big fear - slamming a barge at FTL into a colony-station or planet would ruin either - or theft by a foreign power. But since any misjump could be catastrophically deadly, any jump which does not match a planned and expected course is treated as potentially dangerous.
  There have been attempts at using them for smuggling, quick business opportunities, petty theft, and - in one infamous incident - a crewmember attempting to evacuate his family.
  Notes on tallstone production and implications of cybersecurity
  Interesting. There's no way to "ping" the "network" and - by physics or other means - determine how many other cards are on that "network"?
  Also, depending on how difficult it is to create Tallstone, this creates the possibility that there would be "certified secure" tallstone from well-regarded manufacturers, and riskier-but-cheaper options if you don't care. It also raises the possibility that beyond individual bad actors, governments or criminal groups could set up entire fabs producing batches with access for them.
  Refreshing that the defining system characteristic ... seems to be that it isn't a system.
  Exactly. One of the themes I'm aiming for in this world is that magic is something intrinsically of the heart and soul; it's not something which can be objectively studied. You can still try and loosely categorize it and observe similarities, but magic can't be completely separated from the person.
  fast travel being inherently scary
  Really, I just wanted to cut down on the 'easy fast travel' trope and make the world seem bigger... but it's also a cool idea to play with thematically! I like what you're doing with the social angle as well.
...gross upon gross...
Does this yinrih culture use a duodecimal number base? That's a neat detail.
I don't know much about travel that fast in my world. It's mostly low fantasy (i like fantasy but can't write magic) so there's no teleportation or portals. Some routes are particularly fast if they pass through an area of hyperbolic space, but that's as close as i get to any sci-fi fast travel. I have considered saying the speed of light is infinite, but i'm not sure yet what implications that could have.
- Yes. The countdown also started at 12. Commonthroat uses base 12 but base 24 is also seen in other yinrih languages. Yinrih are six-toed arboreal quadrupeds, meaning they use all four paws for both grasping and movement, and they have 24 digits to count with.
As most fantasy plays out on a single planet, magical fast travel like portals or teleportation could not care less if it is FTL or not. Whether you walk through a portal or cast a teleport spell, both actions are slow enough to easily mask any concept of a universal speed limit like c.
- Hence the "or fast travel" part of the title.
I like a SciFi setting where Portals are the primary means of FTL transit, essentially destructive replicators that disassemble the entrant at one portal, transmits their quantum structure via entangled particle communication, and reassembles them on the other side. The consequences of this are that matter/energy balance must be carefully managed on both sides with stockpiles of raw material to replicate with and the energy to drive it being essential.
Now this method has an obvious flaw, as it doesn't account for traveling to new sectors of space. As such, an alternative method was developed for exploration. This amounts to a mass driver driven by a singularity. An autonomous vehicle amounting to a hardened Portal with interplanetary grade thrusters and a special counter-balance is built and deployed in a system close enough to a singularity to allow transit to it within a few months time.
A vector is calculated with quantum precision. A follow vehicle launches with the FT module held with in it. As the vehicles approach the singularity and gravity acceleration takes hold the follow vehicle fires a high intensity beam array serving to both revers it's own thrust, accelerate the FT module, and provide a protective channel for the module to approach within. High velocity particles are a major threat approaching a singularity, they must be deflected.
The FT module accelerates as it approaches the singularity, beginning orbit, as it orbits the counterweight section is thrust down away from it closer to the singularity, akin to a space elevator, using the same beam tech as the follow vehicle. The counterweight accelerates faster than the FT Module, while cintrepetal force creates a slight outward vector. The vehicle approaches relativistic speeds. Once in the target velocity range, generally 80% of light or .8LS, an antimatter annihilation charge is set off at the base of the FT Module severing the counterweight and propelling the FT module out of orbit and onto its final trajectory. The mother of all slingshot maneuvers.
If the FT Module is release from the gravity well successfully, is on-vector, and has survived functional, the portal onboard is activated, converting mass from the vehicle into subatomic particles to feed the beam and further thrust the vehicle until the thrust-midpoint of transit, by which point the vehicle may have approached 90%+ LS depending on the distance of transit. At this point the the beam is inverted, firing in the other direction to decelerate the FT Vehicle. Typically the target will be another highly massive body, such as another singularity or neutron star, which will be used to decelerate and re-vector towards a local system where another antimatter annihilation charge is used to overcome escape velocity and achieve orbit.
The FL Vehicle may then be commanded via entangled communicator to use its Portal to construct harvester drones to harvest mass from local space until enough mass is gathered to replicate an expeditionary vessel.
Given that none of this process is FTL, it takes many many years between launch and arrival of a portal in a new system. So the question is, who is in command when it finally arrives? What has culture, politics, and biology done in the meantime?
It is a good setup for either side of the portal, on the one hand you have PCs as expeditionary forces heading into an unknown system after many years of process to get there. On the other side you have a Stargate type scenario where a portal ship is discovered in local space. Where could it lead?
In both cases there is the opportunity for a fun bit of Deus Ex Machina, as you must decide just how autonomous the portal ship itself is. Are they dealing with a sentient ship that has been on a solitary transit for years of its own relative time, but centuries of outside time? An anachronism of the old order. Is the portal an inscrutable presence with only the need to feed itself mass and perform its function... and your team doesn't have the codes or features of it's masters? Or even, is this just a fancy automatic door which activates as soon as any being approaches close enough to be sucked in and spit out at wherever it was last programmed to route to? Leaving the PCs in suspense on this point is a lot of fun.
#FTL #TTRPG #SciFi #GM #SWN #StarsWithoutNumber #Starfinder #Traveler

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