Time Travel in Fiction and TTRPGs

This post contains minor spoilers for: Samurai Jack, Captain America: The First Avenger, Avengers: Endgame, Harry Potter and the Prisoner of Azkaban, The Missing, Back to the Future, Harry Potter and the Cursed Child, About Time.

Time Travel. Oh boy, time travel.

The ability to alter the past and reap the consequences of a new future is exciting, and I’d be lying if I said I haven’t dreamed of taking a peak at what’s in store for my own future. In fiction, time travel can make for complex plots that keep you on the edge of your seat as you try to keep up with characters while they navigate past, present, and future events. However, in all my time with role-playing games, I have never seen a system address time travel in a way that was not home-brewed.

This is very understandable because time travel is hard to do, let alone do right. Often, when time travel is used in a story, oh-so-accursed plot holes start popping up left and right, and people get confused very quickly (heck, I’m still confused about the plot of Tenet and that story had professionals behind it).

In an attempt to tackle this beast, I’d like to explore a number of time travel systems in fiction and the implications of using them in a role-playing game, then offer my own take on time travel that I personally used as a gamemaster (GM).

How to Manage Time Travel in TTRPGS

Easy Time Travel Solution: Travel Forward

Well, there’s always the easy answer: take characters forwards in time, not backwards. Playing an out-of-time character offers numerous opportunities for players and GMs. My first ever long-term playable character (PC), Aromus Elden, was a warrior out of time trapped inside a gem for hundreds of years who was eventually awoken in what was, for him, a terrible reimagining of the world he once knew. Grappling with everyone he knew being gone, and the world being so different, was a blast from a roleplaying perspective.

Samurai Jack does something similar, sending the titular hero into a dystopian future due to the nefarious machinations of his nemesis, Aku. The major difference between Jack and Aromus is that Aromus had no way home: he had to live in a strange world built on the ruins of his childhood. Jack on the other hand had a different goal, one that his theme song reminded the audience of every time they tuned in: He’s gotta get back, back to the past (Samurai Jack!).

Aromus, in a way, shares more in common with Captain America from the Marvel Cinematic Universe. Captain America is frozen in time after a devastating plane crash, leaving him stranded as the “man out of time,” and much of his journey involves coming to terms with (or often pushing back against) the new world he lives in. Captain America gets to have a rich story as his identity as a literal personification of the United States is challenged with the current landscape of surveillance and control, and his own desires are sidelined in favor of duty and honor.

However, even Captain America gets his share of time travel (going backwards this time) when his story ultimately concludes in Avengers: Endgame with a trip to the past so that he can finally be with Peggy Carter, his love interest, after his many adventures in the present.

How Can Characters Go Back in Time?

We aren’t settling on any cop-out answers here. Assuredly, the real question is: how can characters travel backwards in time?Well, there are innumerable ways to do that, but as I see it, there are often two issues that crop up with most iterations of traveling to the past. My first major issue with time travel arises if a closed time loop is used.

Time-Turners, Closed Loops, and Fated Destinies

In order to address closed loops, let's start by talking about “The Boy Who Lived” and how time travel was first used in his series. Harry Potter and the Prisoner of Azkaban uses one of my favorite systems of time travel in fiction. The time turners used in Prisoner of Azkaban avoid all of the paradoxes and messes associated with time travel by ensuring that time travel operates in closed loops. In such a system, there is effectively no “going back and changing things” because if a person time travels then they already “went back and changed things,” so nothing actually ever changed because it was always destined to be.

Consequences cannot be undone in the Wizarding World through time travel. When Harry and Hermione go back in time to save Buckbeak and Sirius Black from their undesirable fates, they aren’t changing what previously happened because Buckbeak and Sirius Black have already been saved by Harry and Hermione’s future selves. Harry and Hermione are simply enacting what has to be because it already happened. They have fixed fates, and that’s what stops this system from being totally effective in a role-playing scenario.

If a system like this were to be used then players would be inexorably tied to certain scenarios. Things are meant to be a certain way, so they have to be that way. Player agency is lost as players spend most of their time in the past avoiding changing the past in order to maintain the canon timeline.

This issue isn’t end-all. The Missing, a young adult book series by Margaret Peterson Haddix, revolves around famous children throughout history who have been kidnapped from their original places in time. In order to stop doomsday, the children have to be returned to their original times to act out their predestined fates. Naturally, those who are doomed to befall grisly, premature deaths aren’t too keen on returning to their original times, so the protagonists’ solution is to return them to their times then nab them moments before they are supposed to die, creating the illusion of their death to any and all witnesses.

Playing through this at home could be very fun! However, this type of time travel brings predestination into existence. Players are forced to be more than mindful about their actions because they are locked into a narrative. Suddenly, note-taking isn’t just an option, it’s a necessity.

It feels like agency is lost, especially when characters are returned to the present. Yes, the players and even the GM might not know what happens next in the story, but the reality or illusion that characters are acting of their own free will is snatched away in favor of a divine script. If the past was meant to occur in a certain way, then who's to say it's any different for the present? I have to admit, I prefer knowing that, as a player, I am writing my own future. My destiny should be in my hands, not some omnipotent force.

Butterfly Wings, Sacrifice and Unintended Consequences

This system of time travel, one that emphasizes closed loops, is different from the one seen in Back to the Future, and even the later, incongruent take of time travel used in Harry Potter and the Cursed Child. In these pieces of fiction, people can travel back through time and cause their present to become wildly different, even dystopian, by altering the past. Their actions have consequences because they are changing things; there is no predetermined outcome like in Prisoner of Azkaban. Tiny changes can have monumental consequences! In About Time, Tim, the protagonist gifted with the ability to travel backwards through time, finds that he is unable to travel to periods prior to the conception of his children because he would be unable to conceive the same exact children after doing even the smallest thing differently.

It’s in these systems that my other main issue exists. If GMs employ a form of time travel that allows players to change any event in the past for the better, similar to the ones previously mentioned, then they pose the risk of eliminating the weight of players’ actions and subsequent consequences. That nat-1 that led to the death of a PC in a fight against a nefarious dragon? Now that can be averted with some time travel. The party has information now that will allow them to avoid the assassination of a key NPC? Boom, time travel is your fix.

There are solutions that can be implemented to ensure that tension and consequences still exist: PCs can have a limited amount of time in the past, PCs can still mess things up for the worse if they aren’t careful, PCs can accidentally create other unintended changes, and so on…

However, things ultimately get very complicated, the core issue still exists, and a campaign with this form of time travel runs the risk of creating tension between the players and GM as the GM is put into a position where they have the ability to interpret a seemingly innocuous thing as being the key element to incite the butterfly effect (a part of Chaos Theory that establishes small changes, like the flap of a butterfly’s wing, as being the inciting element for devastating events, like a hurricane). It’s seemingly impossible for players to know what the consequences of their actions will be, making their actions in the past groundless and the consequences in the present completely avoidable.

Additionally, players can run into the same issue as Marty McFly. If players are attempting to go back in time to change the course of their world for the better, then they do so sacrificing some, if not all, of the events that transpired previously in the present. They could come back to a world that is better, but they never got to live through any of that themselves.

All the relationships they built and encounters they had in the present can go poof with one adventure in the past.

There came a point in a year-long Dungeons & Dragons campaign I was running, that after running through numerous different options, I found myself drawn towards time travel as the next step in the narrative. At the point in the story we were at, the players had effectively lost. The agents of the BBEG had enacted their will and set the world up for ruin. The heroes were scattered to the wind and needed to do things that were all but impossible to achieve given the current state of affairs. However, with time travel, the party could turn the battle in their favor and create a finale in which the fate of the world was in their hands.

But then I began to think about the best way to implement time travel. I looked through different iterations of time travel, but nothing really struck me as being particularly effective. I thought about Harry Potter, Marty McFly, Captain America, Samurai Jack... the whole lot of them! But nothing fit what I was looking for.

TTRPG Time Traveling Solution: Use Schrödinger's Gun

I wanted to preserve player agency while also maintaining the experiences the characters had been through, and nothing I saw fit those requirements. So I sat down and racked my brain for a new version of time travel that I could implement, something that would work in this world we were designing, and eventually I was able to create something that I found suitable.

I introduced a version of time travel that was built around the time traveler’s perspective and knowledge of the world.

The main rule of time travel I created was that players could not change things that they already knew. The spell kept them from altering events that had already happened, only if they knew that those events were supposed to happen.

There were numerous other rules implemented to avoid small changes unintentionally affecting those things which the players knew, but that was the core of it all: perspective. What the players knew, and their characters had experienced, had to stay the same. They could not intentionally change those things. However, they could navigate the world and affect in ways they didn’t previously know.

Here is the set of system of time travel I created for my campaign that took place in a 5e Dungeons & Dragons homebrew world:

RULES OF TIME TRAVEL

RULE ONE

Time travel is an expensive, powerful magic. For every year traveled backwards in time, the time traveler must age five years.

1. A time traveler who ages due to the cost of a time travel spell ages instantaneously.

2. If a time traveler surpasses the upper threshold of their race’s expected age then they will die and their remains will be sent to the final destination of their time travel spell.

3. If a group of time travelers is subject to the same time travel spell, then the cost of the group can be attributed to several people within the group or a single person in the group.

4. Only intelligent creatures are subjected to the cost of time travel magic. Intelligent creatures can bring other creatures with them.

5. A time traveler can only bring objects and creatures that they can carry with them while time traveling.

RULE TWO

A time traveler’s past self acts as an anchor for their current self, therefore a time traveler can only travel to a time in which they previously existed.

RULE THREE

A time traveler is bound by the Law of Destiny.

1. By traveling through time, a time traveler carries the continuity of the known universe with them. As such, everything known about the present by a time traveler before they travel to the past must still occur. If a time traveler knows that a person dies in the present on a particular date in a particular manner, then that person must still die on that same day in that same fashion. If a time traveler knows a shipment of fish arrives late at a particular place on a particular date, then that same shipment of fish must arrive late at a particular place on a particular date.

2. If a time traveler does not know the specifics of a particular event but does know the outcome, then the specifics of a particular event can be altered as long as the outcome known to the time traveler is maintained.

3. If a time traveler unknowingly affects something in the past that will affect the outcome of a known event then the Weave will facilitate a new track of events to create the known outcome.

4. If a time traveler knowingly attempts to affect something in the past that will affect the outcome of a known event then the time traveler will be thrust back to their original time.

5. If a time traveler has forgotten the specifics of a particular event that they once knew, they are still subject to the rules of knowing a particular event.

6. If a group of time travelers travels back in time together then their knowledge of the present is pooled together. If one time traveler knows that a particular couple ends up married, but another time traveler does not, that particular couple must still end up married.

RULE FOUR

While in the past, a time traveler’s past self is still present. In accordance with Rule 3, a time traveler cannot interact with their past self because a time traveler knows of all the events that happened to them in the past.

RULE FIVE

A time traveler is constantly tethered to the present by the effects of a time travel spell. After a time travel spell has been cast on an individual, they bear a sigil on the back of one of their hands. If the subject does not have hands then the sigil instead appears elsewhere on their body. The sigil allows a time traveler to return to their present time.

1. Time travel magic can only be used to send a time traveler to the past. However, a time traveler who has used a time travel spell to travel back in time can unwind their sigil and speed up time around them. They can stop unwinding their sigil at any time.

2. When unwinding their sigil, a time traveler ceases to exist in the prime material plane, instead inhabiting a demiplane, unaffected by the passage of time.

3. A group of time travelers bear synchronized sigils. If one person unwinds their sigil then they also unwind the sigils of all their fellow time travelers.

ADDENDUMS

ADDENDUM ONE

In accordance with Rules 1 and 2 of time travel, if a time traveler is subject to reincarnation magic and they die due to the cost of time travel magic then they will be reincarnated with the memories of their past life because of the tether they have with their past life’s past self. However, they will be a new person carrying the memories of a past self. The past self is dead.

ADDENDUM TWO

In accordance with Rule 2 and Addendum 1, a time traveler can travel to a time before they were born if they inhabit a former reincarnation of themself.