Plot Devices: Jump

The better faster than light travel works, the less you can do with it in fiction. Want to rescue a spaceship falling into a star or a planet’s atmosphere? If you’ve got amazing FTL that can pop you over, then pop you and the other ship right back over, there’s no tension. If your FTL has perfect accuracy over incredible distances, just strap it to some missiles, win every battle before it begins. If it can take you anywhere in the universe without fail, what are the chances of getting stranded in deep space?

Methods of travel shape the story around them. This isn’t particularly revelatory. Agatha Christie’s Murder on the Orient Express, Snakes on A Plane, and countless other works of fiction all trap characters in a small enclosed traveling vehicle to help establish suspension of disbelief for fantastic plots (a variant of the locked room mystery). Many other stories force characters to race against the clock, making the method of transportation absolutely central to the story. Countless other examples present themselves. Faster than light travel, though, is particularly interesting. It’s quite simple to make it resemble any other type of transportation already existing in stories. Timothy Zahn’s Night Train to Rigel series even manages to replicate trains in space. FTL is also just much cooler than other forms of transit.

There’s an old saying: restriction breeds creativity. When it comes to FTL drives, there are a few restrictions that pop up time and time again- for good reason. If a starship could just jump/warp/teleport away whenever it wanted, you would rarely have any space battles. And that? That’s a terrible thing.

First off: starting the drive. Most FTL drives in fiction can’t just be used whenever you want, or space battles would never be a thing. Halo, the StarDrive universe, the Tom Swift III universe, and many others solve this by not allowing FTL to be used inside a gravity well, at least without very, very serious consequences. Forcing ships to travel outside of the gravity well gives a timeframe in which space battles can happen without one ship just jumping away at the first sign of trouble.

Other universes, like Star Trek and Star Wars, do allow their ships to jump away whenever they feel like it. Star Trek solves the narrative problems involved by allowing space battles to happen during travel at warp speed- this also runs along with their general 1800s naval warfare theme (with a healthy dose of submarine warfare tossed in). Star Trek transporter beams also cannot go through shields, and have short ranges, making them quite narratively limited. Star Wars doesn’t really restrict usage of hyperdrive significantly, except for a short time period required to calculate their jump. They do, however, get really creative with narrative solutions. The majority of Star Wars’ space battles involve attacking or defending a stationary target, like a planet. The Empire Strikes Back provides a rare example of other sorts of space combat for the series by giving the Millenium Falcon a broken engine. Battlestar Galactica uses FTL jump calculations to a much greater degree than Star Wars- they’re really the only major restriction on it, other than fuel. (Which, oddly enough, doesn’t get worried about too much in many other settings.)

A great number of solutions seem to conform to the gravity well rule, though they often aren’t phrased as such. The webcomic Schlock Mercenary has teraport denial fields preventing FTL entry into an area- usually around a planet.

Another popular solution is allowing faster than light travel only from specific points. Iain M. Banks’ The Algebraist allows faster than light travel only through fixed constructed wormholes outside of gravity wells. Joe Haldeman’s Forever War allows travel only through collapsars. There are many other examples like this.

The final variant that shows up most often is an absence of any FTL at all. This brings with it its own set of narrative challenges, of course. It also tends to require a greater knowledge of physics to pull off well.

One interesting challenge lies in using a solution other than the popular ones. What kind of universe, for instance, pops up when you have FTL that only works in a gravity well? At the very least, you can only visit planets and stars, not deep space. What about FTL that can only take you to any given destination once? No return voyages makes every trip pretty high stakes. FTL that takes you to an utterly random destination? You’d better bring everything you could ever need with you, because you’re not coming back.

Ultimately, as long as an author has a set of consistent rules for the operation of any FTL transit, the readers will generally accept it. Really, that applies to any part of worldbuilding- though not all of them lend themselves to such easy formalistic description. The more you restrict the use of it, the more interesting it’s probably going to be. Even more important than that? It needs to be written well. So long as the author has a clear idea of the specifics of their FTL drive, the reader doesn’t need to know anything other than it works consistently. It often doesn’t even really have to do that, if the characters and plot are compelling enough.

Still, though. You do want quality space battles, right?