Hey Veeky Forums, has any of you ever run a campaign where time travel played a major role in the plot?

Yes.
I tried VERY hard to keep it relatively simple too to cut down on bookkeeping, but it formed a major plot arc of one fairly long campaign I did that I kept referencing back too, a sort of plot arc for the entire game that evolved over time.

This poster here.
I found ways around that for our game, though it didn't exactly involve high-end theoretical time-travel physics.

Sorry, are we supposed to storytime here or is a yes or no answer what you wanted?

Wanted to see whether anyone had done it, mostly to see if it was possible. That said, I'd love to hear a story about it.

Okay, so I'm , It was a Mutants and Masterminds game and I did a "Days of Future Past" issue (the comic, not the film) that was called "Future Tense". Oh, I habitually named my M&M adventures "issues" and gave them titles and such. It gave the players something to reference back to easier.
It involved the usual dystopian future thing that through freak coincidence they got to see, primarily involving a major villain that they had never even met so the entire thing came as a surprise to them because the villain seemingly came out of left-field though I subtly had been foreshadowing his involvement for awhile, they just weren't aware to look for it until after this point.
They spent the issue trying to figure out a way back to their own timeline while fighting the future villlain, but a key thing was that while they could SORT of piece together what had happened to have the world get so fucked up in short order, the actual events were too confused for them to get a narrative timeline that easy. After confronting said villain, he basically killed all of them in a fight which caused them to "wake up" back in the past as they hadn't actually traveled in the future at all, and had instead sort of been "copy-pasted" into it while their original selves were still stuck in that moment of the past, still caught in the "tachyon shadow" of the device that caused the incident. Think of it as casting a really long shadow that has your physical mind and body attached to it, only through time.
While at first they thought that this meant they were safe (as they had thought they had done the "parallel universe" thing, they later began to notice signs of the future that had been coming to pass slowly starting to happen, mostly in the involvement of characters that they met there appearing in the original timeline and such.

Continued.

I had considered a 'Heroes go back in time to set right what went wrong' plot, but I'm having a bit of trouble figuring out an excuse as to why the party and not UltraBadass Mk. III is sent back in time. The best idea I can think of is that the party was born after the critical point that the group is trying to prevent, and a person shares a soul between timelines- which means that they can't enter a time period where they exist, and are kicked out of the timeline if they are born while their 'visiting self' is present.
So only someone who was born after a calamity can go back and prevent it, a fact that severely restricts who can be sent back.

Continued
As it was, the smartest one puzzled out that according to multiple universe theory that while there WERE infinite timelines based on an infinite variety of choices, due to basic laws of causeality the mass number of potential choices that COULD happen were largely irrelevant ones, while major events are generally made to a variety of relatively fixed factors based on a huge number reasons.
So history had infinite branching paths, but a lot mostly made the exact same universe where you had a hot dog instead of ramen for lunch or something, while major events tended to almost ALWAYS happen in a majority of timelines because the number of casual factors leading into them were just too high.
The analogy used in-universe was suddenly dropping a rubber ball you took out of your pocket at one point so it could hit the ground; there are many things which MIGHT happen before it hits the ground and it might hit the ground in different ways, but in almost all cases it'll probably hit the ground at some point.

From then on along with the usual one-off storyline stuff, they were actively engaged in trying to pin down the exact sequence of events leading to the calamity that caused the negative future; they began to constantly refer to this as "trying to catch the ball" due to the analogy used earlier, which they were uniquely in a position to do so because to everyone else EXCEPT them the factors causing the person to drop the ball was completely random as was it's timing, while they knew ahead of time that at some point the ball would be dropped and knew some of the factors involved.

I was running a game a few years back that I expected to be just a lighthearted affair. My players did too, naming their group The Wyld Stallynz because of my love of Bill and Ted.

Eventually they grew to love their characters, two characters finding love and getting married (not to each other. They never admitted their true feelings) and the third was on their way to meeting his parents for the first time when the game disbanded due to me having a child.

About 4 adventures in they are thwarting a small cult gathering in a cave when the cultists all mysteriously due and a weird half-burned wizard appears. He curses them by name and says he's hated them for years. He's ready for his revengeance.

The rogue gets a lucky critical and brings him down to low health. The Paladin swings and... they enter the cave to find cultists gathering. They stop their summoning and shrug and go home.

Randomly from then on they are attacked by this Chronomancer, who when his life is threatens, sends their minds back in time. They meet him at various ages and skill level but always figure out the puzzles or get lucky or somehow beat him back to the future.

The entire time they are helped by Raz (aka Razzy the Rad) the apparently stoned Wizard and enchantment buff at the local college. Razzy was mostly their "what does this item do" bot for a while until they brought in contraband magic forbidden by the emperor. From then on, he became a good friend and confidant and they learned he was essentially imprisoned at the school. He knew too many secrets and instead of magically "forgetting" things, he's forced to work at the college as a whistleblower incase of contraband.

Yeah. The game I'm running, right now, and it did not by my own choice.

ran a chrono trigger inspired plot, where they jumped up and down various time zones solving problems

Every time they visited, he wrote in a notebook. Eventually they noticed he was a lot faether in the notebook then he should have been. He waves it off saying "I'm not supposed to know about that and you guys won't know until later."

They return home to their Inn. They got in cheap since it was considered cursed due to the last adventuring party who owned having a magical riot thrown at the building and burning it down. That same session they hire their neighbor the accountant to help with the business, as they are too busy to do the paperwork anymore.

The next week they are celebrating something special for them and the chronomancer returns and bounces them back in time.

They run to the college to see Razzy is still a Professors Assistant. They try to talk but he shushes them, checks a notebook, and writes in a different one.

That's when they figure out Razzy's notebooks.

They keep their heads low and eventually travel back to the future.

This sort of thing happened from time to time. The found that long ago in the distant future, the now older Chronomancer found a way to separate himself from time, giving him greater power with quite a bit of cost as now his actions can easily be overwritten by himself if he isn't careful.
With each visit, Razzy learns more and more about Chronomancy himself.

Eventually, during the Dwarven Clerics wedding reception, the chronomancer attacks and send them back in time to the day of the fire at the Inn. They check in with Razzy, he's the youngest they've seen him yet. He's really nervous but checks them in to the time and tells them they better go. They decide to meet the adventures who own their inn. Turns out they were assholes. The past-owners insult the players, specifically the Paladin with anger issues. He decides to burn the inn down with the help of a charmed crowd he whips into a riot. His reasoning is it happened in the "past", it's more than likely he was the one who did it, and he felt it was morally okay because they were awful and it already happened, he's just following the timeline.

The rogue, who has gone from caring only for himself to being a bleeding heart over the course of the campaign, remembers the neighbors next door had an infant at the time. An infant who no one ever talks about and was only mentioned once in a hushed, mournful tone.

Believing the baby to perish in the fire, he runs into the neighbors house, grabs the wife and the baby, and runs out the back. He tells the wife to grab the husband at his job and go hide somewhere for a bit. That a wizard named Razzy will tell them what to do next.

Fearing he broke the time line, the rogue has a panic attack. And the three of them slowly fade back to the present day.

And that when my son decides to be born two weeks earlier than we thought.

>And that when my son decides to be born two weeks earlier than we thought.
That may be the rarest sentence in the history of the English language.

This makes it seem like a lot of stuff, but really the time travel was a small side thing to the main story.

The main story they only just figured out the first chapter of clues about as this time travel thing basically wrapped up.

We planned to get back together as my son got older but he's 9 months old today and I'm not sure it's likely.
Schedules just got too different.

I filled them in on some of the overarching plot stuff and finally calmed the rogue down about the baby.

No he didn't break the timeline. He was "supposed" to do that. See, the fire was originally caused by the asshole chef-adventurer next door and the baby was poorly burned. He was sent to live at a monastery so he could constantly be healed. He grew to hate his condition and studied the forbidden magicks, including chronomancy. Magical hijinks later, he ends up changing things enough that he causes the Wyld Stallynz to go back in time to cause his burns. So he hates them for causing his burns and ends up messing his own timeline up. When he gets older he realizes his mistakes (to a degree) and removes himself from time so at least his future self (selves? This is when it gets weird grammatically) can't change due to time fluctuations.

When they save the baby, only the chronomancers after the time removal are still left around, ie: all the ones they've met so far.

The baby, to prevent meddling by the chronomancer is sent to a different time under a different name to be raised by loving adoptive parents. This was decided by Razzy who convinced the parents. He said he was adopted and raised by loving parents and asked if they approved of him. After saying yes he removed his hat, allowing them to see his face better. They started weeping, seeing it was their grown up son.

Everyone really seemed to like it and it only took me, like, two years of weekly gaming to be able to tell it convincingly.

My little dude just couldn't wait to start hanging out with me.

>Chronomancer causes his own parents to put him up for adoption so he can become the person he is now.
I pride myself on deepest lore, but that blows anything I've ever planned out of the water. Except for maybe the 'princess of the drow is actually the daughter of my old PC' shit, but that hasn't been run to completion and I figure my players are going to go ape when they finally realize who she is.

I once ran a campaign, not such much involving time travel but time distortion. A major plot point was that the northernmost kingdom was running at about 1/6 normal time, so while the world had advanced 60 years, the kingdom had only experienced 10. Thus, the PC's who had been magically bonded to the queens will, obligated to do her bidding on pain of a slow, wasting death, were having to venture out and carry out her orders, which were being made on fifty year old information, while the queen refused to believe them whenever they tried to tell her about the time distortion, because of how ridiculous it sounded, and her isolationist policies meant she had no way of independently verifying that information.

I originally didn't plan it on purpose. But after a few encounters and learning more about my NPCs, I figured it couldn't work any other way.

That's how I DM, really. I plan a bit but when I look back at the narrative I created over time, I connect bits and pieces and then build on THAT and act like I planned it the whole time.

Players think I'm a genius and that makes it really easy to get games going.

I sort of do this, but it helps that I have an idea of what I want to do beforehand and I tend to be pretty good at getting players to play into my plans.
The princess I mentioned was originally made to fill a stopgap for plot-relevant characters and I realized that this possible kid fit the bill perfectly. She was actually meant to be relevant in a different campaign within the same setting, but the situation bled over.

This was a campaign in the 4th edition DMG 2, including le ebin twist.

Yes, many times. Time traveling campaigns are mind benders for 3 reasons. 1) The timeline will change without notice. 2) If you don't have Temporal Inertia you won't be aware of or remember the changes. 3) EVERYTHING can be retconned - including your character's very existence.

In GURPS - 2+ times as a Jumper, 3+ times with Temporal Inertia (1 hero, 1 mage, 1 mutant) and/or an Ultra-Tech Gadgeteer (no Temporal Inertia - so I got screwed at a few points and didn't know it in game).

In Mutants and Masterminds - as "Porter" (aka Space Hobo - a mysterious paranoid immortal who can teleport to any dimension, place or time)+ and as "Kaos X" (a WH40K style manifested demon in a Kingdom Hearts campaign)*.

+ Awesome campaign. Don't underestimate a teleporter who can attack teleport. ;)

* Awesome campaign. I got captured so I joined the bad guys. I subverted and corrupted everyone. By campaigns end the party didn't trust me. Unbeknownst to the party, we survived to get to the final boss and beat him because of my intelligence gathering, misdirection and shenanigans.

I'm doing this in GURPS but in reverse. Essentially, the players accidentally a unique and impossible timeline, and it's gained so much chronological improbability and momentum that it's collapsing all time into it.

In other words, the players are not time traveling.

Time is traveling TO the players.

Yeah. I tried running a Continuum game once.

In the plot? No.
In the setting? Yes.

There was some young magically talented king who decided it was a good idea to explore other dimensions with his magic. Accidentially went to one where time passes a lot slower than his own dimension.

Everyone thought he was gone for good when he didn't return, his brother took over, had children who ruled after him and hundreds of years passed.

Suddenly the guy comes back and has effectively time-travelled, as for him only minutes since he left have passed. Obviously he's not happy with having missed so much and even less happy with having someone else sit on his throne.

Eventually he lost the war that resulted from it, but to win the current king had to make a deal with one of the undecided nobles that lets them gather massive amounts of money from tax excemptions and tolls on trade they may collect (a right usually reserved for the crown in the kingdom).

This leads to the current line of kings' downfall many years later when he can't pay his debts after a lot war anymore and the merchant-nobles bail him out in exchange for the crown.

The portal to that dimension can still be opened by the way, so if the players ever decide to use it they can be my guest.

Really, the trick about timetravel is to only allow it forwards, not backwards.