Time Travel is a daunting mechanic for any GM to attempt to incorporate in their game. While using time travel as a platform for historical settings and conflicts can be fun, eventually your players are going to ask “wait, what happens if we show Beethoven a recording of his Fifth Symphony before he writes it?” or, even more problematic, “can I go kill my grandfather?” These are questions which, for the sake of the integrity of the concept, can’t be left completely unanswered (though you can probably tell the player trying to kill his own grandfather to drop it before something bad happens). The good thing is that time travel as a game concept leans heavily on improv, and does so in a way that can be very helpful with developing your improv muscles in a fun, non-game breaking way. That’s because with time travel, you can come up with whatever consequences you want…the players already have the mechanism to fix it.

So let’s talk about time travel role-playing in general. There aren’t many time travel RPGs, in part because conceptualizing time travel and then writing rules around time travel are difficult. There are two games I can think of which typify the two general approaches to time travel in RPGs, and unsurprisingly one is much more successful than the other. The first, more successful time travel RPG is Doctor Who: Adventures in Time and Space. Now, for those of you who haven’t seen the long running BBC series, Doctor Who is about an alien, The Doctor, who travels through space and time in his spacecraft, the TARDIS (Time and Relative Dimension in Space), which is shaped like a police call box and bigger on the inside. The show’s approach to time travel is exemplified from a statement from the Tenth Doctor (The Doctor has ‘regenerations’ after which they take on a new body), namely that his travel involves “a big ball of wibbly wobbly, timey wimey stuff”. In other words, the exact mechanics aren’t really important, and something as troublesome as a paradox will only come up when it’s relevant. The Doctor and his companion can go hang out with Vincent Van Gogh for a week and barely affect history at all, but when the Doctor’s companion interferes with the car crash that kills her father, everything goes to hell and monsters show up. Why? Because the plot dictated it. Don’t worry about it. This can be rather unsatisfying, but it makes it much easier to create a world filled with time adventurers flitting about, and have the Doctor encounter friends and rivals all across history without really needing to worry about the consequences of how they got there…or then.

The other direction you can take for time travel RPGs is one where these paradoxes are deadly serious. Continuum: Roleplaying in the Yet is a game where the characters are joining a “Time Police” whose mission is to prepare humanity for the discovery of time travel in 2222. There are time criminals to catch who are trying to damage the timestream or use time travel for personal enrichment, and the characters must stop them. The way that the game addresses time paradox is through the idea that the universe doesn’t tolerate paradox, and those whose existence is paradoxical slowly cease to exist. This is measured as “frag” in the game, and if you accumulate enough frag, your character ceases to exist. Well, in theory. As part of Continuum, each player keeps a journal of actions where they use time abilities, because their character needs to account for those abilities working in their travels. So you can call on an ability where a version of you appears with a gun for you to use against a time criminal, but that then means you need to go back in time, get the gun, jump forward in time, give the gun to yourself, and then later jump back in time and put the gun back so you don’t screw anything up. Miss any of these steps, get fragged. So there’s a lot of bookkeeping involved. And what actually happens if you get too fragged is…kind of boring. Some other member of the time police will fix your mistakes, you’ll get a disciplinary write-up of some sort, and the game goes on as if nothing happened. Now, this all makes sense. A Time Police force would have nearly perfect knowledge of the timestream and nearly perfect ability to fix it. It’s also incredibly lame for a game. Player disempowerment is never the way you want to go, even if it makes sense.

Now let’s assume that neither of these is entirely satisfactory (if one of them is, I recommend you pick up the applicable game noted above). Having time travel being consequence-free sounds too handwavey, and having a time police step in every time you get out of line sounds boring. So what’s the middle ground? Ideally, we’re looking for something in the “Back to the Future” arena of time travel: it’s easy to mess things up, but generally it’s easy enough to fix things too. While you could go the Journeyman Project route and provide lots of interesting ways for your characters to be uncreated or straight-up murdered, there does need to be a balance between “interesting, challenging game” and “well *that* was a different TPK than what I’m used to.” So let’s focus on the time travel, and leave the danger level to your group’s personal taste.

Like most improv-heavy games, a time travel game will have an inciting conflict and then a number of follow-on conflicts. So first, you’re going to write a reason for your characters to travel back in time. Could be a rescue mission, some sort of heist, or even a freak time travel accident. That creates your setup, and your first goal for the players: rescue the person, steal the thing, get back to the present alive. But pretty much as soon as the players start working towards this goal, you’re looking for a place where things could go wrong. I’m going to do “Back to the Future” positively to death, but it’s a great example. In the second movie, Marty and Jennifer go to the future to help save their children. However, in the interim, Biff gets a future sports almanac and steals the DeLorean to bring it to past Biff, changing the present completely. The reason this works for the movie and would work for a game is that Marty is the one who buys the almanac in the first place, setting this whole ball of nonsense rolling. When something in the past gets messed up like that, it should come from something your characters did. This is simply for player empowerment reasons: players have stronger reactions to conflicts they create, and messing things up outside of their control usually isn’t fun. It does, however, create complications when you get into the resolution stage. The simplest way to fix a problem would be to stop the other version of the characters from doing it…but how do you run that scene? Figuring out other ways to solve the problem should be on your mind as you’re figuring out what has happened.

After you’ve identified what the characters did, start thinking about how it messes things up. Let’s go Back to the Future again:

Marty and Jennifer go to the future ⇒ Marty buys and then throws away sports almanac ⇒ Biff takes almanac, steals the DeLorean ⇒ Past Biff gets the Sports Almanac ⇒ Biff becomes crazy rich and starts Dystopian Hill Valley

The point at which the characters stop this line of events is not at the start point, it’s down the line…the thing that can’t happen is that Biff can’t get the sports almanac. That then creates a different adventure for the characters to have than the one that created the problem in the first place.

The key to executing adventures like this is in thinking on your toes and seeing where there are opportunities to create complications. This is true in all games, but in time travel you have a lot more leeway. Some NPC gets killed? Think about how their offspring changes the future. Vehicle get destroyed? Think about what it was supposed to transport that now won’t get to its destination. Don’t feel the need to follow every lead…the butterfly effect can happen, but chaos theory does not let us assume it will happen with every change. As your characters are going through their adventure, be alert, and when an idea catches your eye, immediately write it down. If you think of a fun consequence, even if it’s a little wacky, write that down too, and start sketching the middle after you begin the process of introducing the new problem to your players. This will keep the game from bogging down, and keep you listening. The best way to prevent writer’s block in that middle part is to listen to your players. A session where your players solve a puzzle through brilliant deduction sounds very similar to a session where your players come up with a neat theory you hadn’t thought of, which you then quietly steal and insert into your ongoing conflict. This is true for all improv, not just time travel, but you’ll find with time travel and other outlandish concepts that many of your players will be thinking on very different approach angles than you are. There’s no better way to both save time and reward creative thinking than to steal these speculations from under your players’ noses and work them into the session.

Time travel RPGs are a microcosm of improvised games in general. What makes time travel fun are the strange knock-on effects of changing the past, and GMing a game like this requires you to make judgments about what those effects are in real-time. This is the same way virtually any improvised game would work, but with time travel, you have the benefit of fewer boundaries, more player speculation, and more opportunities to turn things around if the scenario becomes untenable. It’s also important to have an environment in which you feel like anything could happen, because that makes it easier to take ideas and run with them, as opposed to feeling like your idea wouldn’t work or isn’t good enough and then self-censoring. Time travel is a giant cause-and-effect playground, but the work of being a reactive GM and creating the causes and the effects can apply to any game which benefits from improvisation. Which is, in my opinion, all of them.

Doctor Who: Adventures in Time and Space is available at DriveThruRPG. Continuum appears to be stuck in the Yet…any  hints or news about a legitimately produced PDF of the game should be sent to us at cannibalhalflinggaming@gmail.com, or tweeted to @LevelOneWonk.