“Know the rules and the rules will make you free.” - Orson Scott Card

True. And the more you know the rules, the better you will know and understand when you can bend them a little or occasionally break them.

Although all sub-genres of science fiction have their own little quirks and foibles, it’s true that, along with space travel (mentioned previously) certain other science fiction subjects need a little more thought than others. The more recent sub-genres are often subtle spins on the older styles, and we’ll go into the sub-genres a little more later on. But for now, it’s time to tap into the subject of time travel (DoooWeeeeOooo!).

Time Travel

This is possibly one of the most fascinating and potentially complex areas of science fiction. We could go into immense detail here, but doing so often ends up with the writer trying to work out whether he still exists and the reader wondering why he should (“Luke, I am my own father”).

Suffice to say, it’s very easy to tie yourself in knots. But, as with all things, if you have your rules and edges in place, you should be able to keep your universe relatively straight.

There are several variations on the theme of Time Travel, all of which have been ‘done’ to a greater or lesser extent in film, tv, or literary form. They can take the form of Romantic yearning, comedic mishap, more serious social commentary on whether ‘we should if we could,’ and many things in between.

So, what kind of time travellers are your characters? There are a few basic types listed below as a start point :

The Immune: a time traveller who can go back, make changes, but continue to exist as they are ‘outside time’ and therefore be immune to the change.

The Careful Traveller: someone who can make changes but can also potentially destroy or irreversibly alter their present. So, this sort of traveller can do things like save people who’re about to die, or great works of art and bring them to their ‘present’ but has to be very careful about who and what they save, and how.

The Inertial Traveller: where time has inertia, so even if Genghis Kahn was wiped out for example there would still have been a similar leader and empire, and by the time the traveller gets back to ‘now’, time will have reasserted itself.

The Inconsequential Changer: a traveller who can only make changes that have no long-term effects as any universe in which you change your own future could not exist. So you could go back and change the coffee cup your father drank from on the day of your conception, but not interrupt the act that produced you.

The Watcher: can travel and watch events but not interfere in any way and would be invisible to the local denizens of that timeline.

The Lodger: where the traveller looks through the eyes of someone in the past. The brain he/she is in doesn’t know they’re there, but they can observe.

The Younger You: similar to 6, but where the traveller goes back in time within their own life and mind. There are two subvariations to this one; one where the traveller watches, the other where the traveller can act and change things, but the younger would have no memory of what they’d done whilst the other ‘him / her’ was in control.

The Observer: time TV, where the traveller doesn’t travel as such but watches the various timelines unfold from the comfort of their Time Sofa.

The Avatar: where a machine or alternate body is arranged for the traveller to experience the past. Their consciousness is downloaded into the avatar and they get to wander around in it.

There are almost infinite variations and cross pollinations of the above ideas, but these tend to be the most common in literature. As long as you, the writer, know where your boundaries lie then you should be able to write it convincingly.