time travel in an RPG

[Shinizak]

So lets say you have time travel as a major mechanic in your game like mage the ascension (but not primarily mage) , how does one handle time travel into the past & future without keeping track of 20 billion character sheets?.

[Tvtyrant]

So lets say you have time travel as a major mechanic in your game like mage the ascension (but not primarily mage) , how does one handle time travel into the past & future without keeping track of 20 billion character sheets?.

I used time as a great circle; so you can only travel in one direction but that direction eventually lands you exactly where you began. So if you start in a low medieval time and travel forward in time it becomes first like Eberron and then like Spelljammer, finally time flips and you go forward through all of the times before yours and depositing you at your original time, with everything unchanged except your party.

Another way to do it is to have the timeline become so fragmented that you run everything as a series of one shots, and anytime you do anything everything changes again.

Still another option is to have time travel be self-correcting, so your actions in the past don't alter the present, and your actions in the present don't alter the future.

[nedz]

Make travelling forwards in time a lot easier than travelling backwards. This will reduce your problems considerably.

[Sipex]

Just do it like Chrono Trigger does. The events effect the future but somehow it's never as complex as it should be OR you were supposed to do what you did so nothing changes at all.

[Shinizak]

I guess what I mean is, let's say player A, B, and C are playing a game of (insert title here) Player A wants to go back in time to help player C fight the lich lord again. Player B wants to go forward in time to see what happens later in the campaign. Player C wants to go back in time to go the future where he's fully upgraded that ultimate suit of armor and give it to his past self before he fights the lich lord.

None of these past events happened int the player's games, none of the players have their stats saved from that time, and the DM has long forgotten the stats of the lich lord. How would you create a crunch system supporting this?

[kestrel404]

There are two schools of though on time travel.

In the first, you cannot change that which you know to be true. Paradox is impossible because no matter what, the cause of that paradox will be rendered meaningless by fate itself. This model of the universe presupposes predestination. It requires a LOT of bookkeeping, and is usually best dealt with by either a supernatural force or a group of timeline-conscious superpowered time travelers keeping the timeline neat and tidy (usually by the expedient of cutting the heads off of anything that sticks its head out of the time stream).

In the second form, the river of time forks and branches. This might happen at every minor decision (should I make my sandwich on white bread or wheat?), or it may just be the big things that can cause time to split (who won World War II?) and the little stuff is just lost in the background randomness of time. In this scenario, time is literally what you make of it - paradox does not ocurr because any change that would CAUSE a paradox is a big enough change to split the timeline. So if you travel back in time and kill your own grandfather before he meets your grandmother, the timeline in which you are born still exists, and you still travel back in time, it's just that you're travelling down the OTHER fork in that river as of now (and you will continue to do so until you go back in time and STOP YOURSELF from killing your grandfather).

The second version is best for lighthearted games, or if you don't really want to keep lots of detailed notes. If you're interested in the first type of game, look up Continuum, the time-travel RPG. It's got a LOT of info on that format of time travel.

[Tvtyrant]

Not allow it? Time travel shouldn't be in PC hands like that, its too powerful.

If your set on allowing them to do this, then I would find out how strong the characters are going to be when they go to fight the Lich and make it a level appropriate encounter. If they are freakishly strong have the Lich travel to a time where he already succeeded, so they have to fight him on even footing anyway.

But seriously, you should not be allowing this form of time travel without some sort of serious repercussions (like time guardians coming down on them hard for it). They could go to the future and pick up laser guns, or go into the past and kill the Archfiends before they get their bearings.

[Sipex]

Oh, erm.

Hire a secretary?

Again, my vote is for chrono trigger, except in a different sense now. You have predesignated points they can travel to and they can never interact with their past selves (since once the portal is accessed, it flows forward in time with the players while they're present in that time period)

[kestrel404]

I guess what I mean is, let's say player A, B, and C are playing a game of (insert title here) Player A wants to go back in time to help player C fight the lich lord again. Player B wants to go forward in time to see what happens later in the campaign. Player C wants to go back in time to go the future where he's fully upgraded that ultimate suit of armor and give it to his past self before he fights the lich lord.

Go out and buy Continuum. It covers every one of these examples explicitly within the rules. Several of those are considered 'basic combat maneuvers'!

P.S.: The 'Advanced combat maneuvers' give me headaches. ;)

[randomhero00]

You could make it so only their souls travel back in time. In other words, no going back to give equipment. Technically it could get messy but it'd be a lot less likely since if you failed in defeating the lich lord you'd either go back right away (same char sheet) or you'd level up and not use time travel and go back to kick his butt (same updated char sheet).

You can also simply make it more limited, like, only going back in time at certain points, or 5 minutes.

[valadil]

Make it up. I don't think time travel should have mechanics. If there are mechanics the players will know how it works and be able to use it deterministically. If this is something they're trying for the first time, there's no justification for them to understand it so well. Either figure out the repercussions of their plan working or figure out how paradox will prevent their plan from working, thus preserving the timeline they already lived through.

[gbprime]

I flowchart it, myself. If the PC"s are going backward in time, then certain things they already know are a result of something they have done, perhaps even their own origins. Plan this stuff from the beginning of the campaign and you can hit a new "coolness factor" with your players.

The firm rule to use is that no matter what they do when they are back in time, they cannot change the here and now, because the here and now has resulted from all the time travel that has come before. (Of course it's just fine for the players not to realize this and try anyway...)

[panaikhan]

There was a film about it once.
Time travel was only possible by pushing the person's essence (spirit, soul or whatever) up or down the line of direct descendants. If the person didn't have any family tree left by year X, then that was the end of the line (literally).
Once at the target time-frame, they 'possessed' their relative in order to effect events.

[AstralFire]

Why would time travel require additional character sheets?

[dsmiles]

I prefer to do time travel as an infinite amount of alternate Prime Materials, much like WoT. Anytime a decision is made, the "time" splits in to alteranate Primes, one where you made "decision A," and one where you made "decision B." The more likely the decision, the more "real" that Prime becomes. The "Main Prime" being the one where you actually chose the course of action that you followed. The less likely the choice, the less real (and subsequently more "faded") that Prime Material becomes.

[Earthwalker]

Why would time travel require additional character sheets?

I think it has to do with one of the examples by the OP.
Two players A and B. A is lvl 15 and two weeks ago failed to kill a Lich. Now player B goes back in time and helps A kill the Lich then comes back to the current time. Where Player A is now lvl 16 not 15 and has more items he stole from the Lich he did beat 2 weeks ago. So Player A has two character sheets one with the Lich dead one with him alive. It gets more complicated the more they mess with their own pasts.
I don’t think this is an approach to use just showing why it might be.

[AstralFire]

Oh, thanks, I missed that post.

1) Don't let them just use time-travel willy-nilly. Every plot ever formed around time travel either limits the times one can go to or the amount one can use the effect.
2) Make them go in groups 99% of the time.

[Totally Guy]

There's a Doctor Who RPG. Is the time travel in that a suitable system or is it just used as a setting enabling device?

[Earthwalker]

I would keep with the idea of locking the player characters time lines so they don't interfere with thier past or future selves. Then use time travel as more a plot device.

Of course saying that I am going to look into getting a copy of Continuum as it sounds fun.

[Jokes]

Our group has recently come into possession of a time machine. The first scheme player X had was to go back in time and kill player Y's dad (as an act of revenge, long story there). The DM, rather than just nix it and still avoid universe destroying paradoxes, suggested instead he could go back and become player Y's dad. I look forward to seeing how this turns out.

[umbrapolaris]

the "Chronomancer" supplement for AD&D gives valuable information about time travelling. if u may acquire it (i remembered you can download it freely on WoTC) it will answer your question. i wish but never found a supplement like this one for D&D 3.x

[randomhero00]

One more idea from me...make the rules change. Time travel is paradoxical anyways. Make the rules change each time the travel. They'll be more hesitant that way about abusing that power and it will be a fun side quest to figure out which kind of time move they did.

[Tvtyrant]

Have the device suck an ungodly amount of xp out of the users, which will prevent them from wanting to use it.

[Chrono22]

I go with branching timelines. In the absence of time-travel interference, a main line will progress from one point to another in a consistent fashion. The introduction of time travel causes a divergence or split, wherein a second timeline or branch is created. The two lines compete for dominance until one is subsumed by the other, they merge, or until the branches become distinct realities.
So, for example:
Bob the wizard decides to Teleport through Time to ancient Oerth. In the process, he creates two branches: one in his origin timeline, where he is absent, and one at his destination. If the changes Bob creates in the new branch are on the level of changing the face of the world, how magic works, and the creation or destruction of deities/nations, the new line may become its own distinct prime material plane, and would exist alongside the plane Bob originated from. If the changes he made were small, in time the results of his actions would become inconsequential (statistics and the march of time would take their toll, and would slowly erase his mark on history). Eventually, the two Oerths would be indistinguishable from one another- they will have merged.
The last possibility, is that Bob begins hopping back and forth between one time line and another, and in the process creates a large number of competing timelines or branches. In the process, he'll begin creating paradoxes. Some are contained loops- these are relatively safe, in spite of themselves. Being your own grandfather may not make much sense, but at least it's precise. The more dangerous kind of paradox, is this kind:
The statement after is true/The statement before is false. In isolation, these statements are harmless. But combining them means mutual annihilation. In this way, the interaction of these competing timelines causes these types of dangerous paradox to aggregate. Eventually, the integrity of all of the branches is in peril.

[Hanuman]

The problem with time travel is just how incredibly wild it is.

You see, time is very much like space in terms of metaphysics, let me explain.

3D minus time is a 0th dimensional time plane, it's an imaginary point in the time/probability system, once it enters a length it's now got a beginning and end and a fixed length of time, let's say perception collapses a wavefront in one reality which acts from 1 point in time to another in that dimension.

That's a 1 dimensional timeframe. (4th dimensional)

Now, if we assume even a single split in time during that time frame to another reality, let's say you went slightly more left than right while walking, that's adding a branch off from your timeline, regardless of how many branches it might as well be a 2 dimensional picture. (5th dimensional)

Now, you could travel from one point in time to another to "jump" forward or back, but that would require folding the timeline, and including the folding of a timeline would bring another dimension into it, which would make it "3d time". (6th dimensional AKA infinity)

But bringing one time string and jumping to another point in the string requires bending the string through OTHER time lines and other realities, which means you are almost never assured to travel along your 4th dimensional line instead of a random but probably fairly parallel 5th dimensional one.

That's how I play it anyway, but honestly I try at all costs to avoid time travel unless its "crazy accident" style.

[Siosilvar]

The problem with time travel is just how incredibly wild it is.

-technobabble-

#1 rule of time travel: It will make your head hurt.

The new verb tenses alone wioll haven be more than enough.

[Safety Sword]

I once ran a campaign where all of the PCs were killed by the BBEG in the first session.... OK not a glorious start.

However... divine intervention!

They are sent back in time, to stop the BBEG whilst he was younger. But it didn't work (several times)!

The final battle was the same as the first battle. Only this time they narrowly got through it, saved the world and got all the naked chicks.

T'was awesome.

[Hanuman]

#1 rule of time travel: It will make your head hurt.

The new verb tenses alone wioll haven be more than enough.

http://www.youtube.com/watch?v=uY_ZgAvXsuw

[Aotrs Commander]

I always go with the Rolemaster Time Riders school of thought on this. In that you can't change visible history. You can't go back and save your mate who got blown up around the corner and change history so he doesn't, but if you are really clever, you can make it so that it was that he was only appaently killed (e.g. you replace him with a clone that took the final blow, or teleported him away and left scattered body parts instead ot something.) It, of course means that what did always did have happened, your earlier self just didn't know that it had always happened like that...

There's a whole faction of bad guys called the revisionists whose goal is to do that to all of history, so that, basically, by the time they reach their own time, all of recorded history is basically a lie and in reality they've realled ruled everywhere secretly from day one. Nasty.

Time itself cannot be changed in the visible, recorded aspect though, so you can't pop back and use a laser cannon on Julius Caesar - basically, if you try Reality Fiat makes things go steadily wronger and wronger until you stop trying (either willingly - or otherwise...)

This has the advantage of making it really easy (comparitively), since you don't have to worry about changing history, because, basically you can't.

[DragonOfUndeath]

I would go with the Many-Worlds theory. Paradox-free time-travel enabling you to do whatever you want without affecting your own universe. C fights the Lich-Lord and loses, 2 weeks later A goes back to try and change the outcome but goes into Universe2, A helps C2 defeat the Lich-Lord and can then stay in the Universe2 from that moment on with a dead Lich-Lord, A and A2 being slightly different (2 weeks age difference, different memories etc). Or A can go back to Universe1 where nothing has changed except A has been missing for however long he spent in Universe2 (Referred to from now on as TX) and has memories of fighting and killing the Lich-Lord. A can also take C2 back to Universe1 splitting Universe 1 into 2 other Universes, Universe1a and Universe1b. 1a is where A comes back alone and has been missing for TX. In Universe1b A and C2 appear TX after A left. Each time you have a choice to return with or without something you create another Universe. As every decision makes another Universe anyway it doesn't really matter.

[trajet]

Up until recently I was GMing for my group while we were playing Alternity. I just used time travel as a mechanic for story that they didn't control. They wouldn't have been able to figure it out in game. I think putting time in a player's hands can be very dangerous, not because of repercussions story-wise, but because it might get the group off story and soon you'll just be following crazy timeline one-shots.

[Fiery Diamond]

I always go with the Rolemaster Time Riders school of thought on this. In that you can't change visible history. You can't go back and save your mate who got blown up around the corner and change history so he doesn't, but if you are really clever, you can make it so that it was that he was only appaently killed (e.g. you replace him with a clone that took the final blow, or teleported him away and left scattered body parts instead ot something.) It, of course means that what did always did have happened, your earlier self just didn't know that it had always happened like that...

There's a whole faction of bad guys called the revisionists whose goal is to do that to all of history, so that, basically, by the time they reach their own time, all of recorded history is basically a lie and in reality they've realled ruled everywhere secretly from day one. Nasty.

Time itself cannot be changed in the visible, recorded aspect though, so you can't pop back and use a laser cannon on Julius Caesar - basically, if you try Reality Fiat makes things go steadily wronger and wronger until you stop trying (either willingly - or otherwise...)

This has the advantage of making it really easy (comparitively), since you don't have to worry about changing history, because, basically you can't.

This, along with making the idea inherent in this, stable time loops, quite clear. Basically, making everything stable time loops and making things "changeable" only in the way the quoted post says is the easiest way of handling things that doesn't require a forked time stream (also known as multiple universes). I really don't like forked time streams, mostly because the whole idea that there is more than one of you is...disconcerting.

And the third possibility, overwriting reality (what happens in Chrono Trigger) is EVEN MORE disturbing when you think about it: just by time traveling you are erasing the existence of people by changing who they will become or by preventing them from being born.

So as I see it, there are three choices:

1) Stable time loops (my favorite, but seems to be more predestination-ish)
2) Forked time stream (who is the "real" me? The essence that makes me unique...how is it that multiple separate people have it? ... ... ...)
3) Overwriting history (makes you worse than a murderer if you change stuff, even for the better, as it prevents people from existing who did exist...snuffing out their existence. Like people who are devoured in Shakugan no Shana.)

I suggest you decide what kind you prefer before deciding rules.

[Psyren]

The Chronorebel from Hyperconscious has an ability that lets them take the party back in time. You can travel back a minimum of 17 days into the past, with a maximum of 500 years per ML.

For Chronorebels who mess around with history and alter the present too much, the DM is allowed to rub them out after 7 days via the Edict of Time (basically, misfortune falls the Chronorebel and his party.) However, some uses of the ability can be benign enough not to cause retribution - such as conversing with a historical figure, retrieving a sample that won't be missed, or witnessing a historical event firsthand.