Time-Travel

[Bulix]

Hello,

I am a DM and I would like to give my party a time-travel adventure. Only, the players won't know this until the end. Something like they have to steal something from their past, which is cool. The only problem is that before that happens they will have to encounter the future version of themselves without knowing it and I can't be for certain what they will do. Another option is for them to never see each other. Beware the paradox! More stealthy. What do you think?

Thanks :smallbiggrin:

[Psyren]

I think you definitely need to plan this out a bit more concretely. "This sounds cool!" will evaporate fast once you start getting into all the paradoxes and headaches involved.

Specifically, figure out:
1. How they time travel
2. WHY they time travel
3. Past or possible future? (Why would they meet their future selves in the past, btw?)
4. How far back (or forward)
5. The history of the setting itself, as well as its potential future
6. If the past, can they change the present, and if so by how much
7. How long will they be there/is there some condition they have to satisfy to get back to their time

Things of that nature.

[Lord Il Palazzo]

Here are the only official time travel rules I'm aware of for D&D.

http://www.wizards.com/default.asp?x=dnd/pg/20030409b

It's a specific spell called Teleport Through Time (Sorc/Wiz 9) but the guidelines it gives could easilly apply to all time travel if you wanted them to (or not if you don't). Regarding meeting yourself, it says this:

In the case that a traveler meets himself, the two travelers instantly lose control and attack each other with every ability and item at their disposal.I could definitely see not wanting to play it that way.

It also has a special note on paradoxes and violations of causality that basically says to assume that if a cause is removed, another cause will take its place to create the same ultimate effect so you don't have to worry too much if someone steps on a butterfly or something. Kind of dull, really, but practical for a DM I suppose.

[PrismCat21]

The future-selves that they meet, could be how they would have ended up if they had not traveled through time in their future-selves past. :smallfrown:
The player controlled PC's are now having very different (life changing) experiences, and so will naturally turn out very different than their current future selves. Their future-selves have already lived their life and had their own experiences, and should not be retroactively changed by the decisions of the past versions of themselves(PC's).

It's a simple explanation, where you don't have to worry much about details. :biggrin:

[demigodus]

There are a few interpretations of time travel:

a) Changing events in the past changes the future
In this case, butterfly effect means that the past is going to be VERY different

b) The universe conspired to ensure the future. So a predetermined future, whatever you do, that will end up happening. Changing the past won't change the present/future

c) Can't change the past. The universe's laws ensure that whatever you do can't change a past that has already happened. Raises some questions about free will. Generally creates stable time loops

Determine ahead of time which interpretation you want to go with. You might want to explain that to your players once they realize they are time traveling. In case they have a different idea of how time travel should work.

Other than that, when they build their characters, ask them to also make character builds for 5 levels later. Those 5 levels later, can be their future selves. These are the builds that would have happened if they didn't have whatever encounters you are going to give them. They can meet those builds. Just as naive as the players are when they first start your game

[Malroth]

Option D) events can happen without causes and the universe doesn't care, You go back in time and kill your grandfather and the police arrive and arrest some babbling maniac who claims to be from the future.

[demigodus]

Option D) events can happen without causes and the universe doesn't care, You go back in time and kill your grandfather and the police arrive and arrest some babbling maniac who claims to be from the future.

Also known as "not option C"

That still leaves options A and B. Or to reiterate, the "what happens to the present when you change the past?". That is the question that tends to get asked with time travel. That is what those options are trying to address. Yours... doesn't.

[hiryuu]

Option D) events can happen without causes and the universe doesn't care, You go back in time and kill your grandfather and the police arrive and arrest some babbling maniac who claims to be from the future.

Option D.1) The universe is not anthropogenic, and time is not a "line," nor is it a sequence of cause and effect. You can go back in time and kill your grandpa but it won't be the grandpa you didn't kill because that grandpa is already your grandpa, which we can determine by observing that you exist. You can't go back into your past because clearly you weren't there. Think of time as a set of geographical coordinates: what you do in the Colorado Rockies doesn't really have an effect on New York. Why should it?

Note this is how actual time travel is theorized to work.

[Ashtagon]

First, decide what the "rules of time travel are". That will decide pretty much everything. Note that some rules of time travel, while entertaining, make for better novels and film scripts than RPG sessions.

[Ranting Fool]

Option D.1) The universe is not anthropogenic, and time is not a "line," nor is it a sequence of cause and effect. You can go back in time and kill your grandpa but it won't be the grandpa you didn't kill because that grandpa is already your grandpa, which we can determine by observing that you exist. You can't go back into your past because clearly you weren't there. Think of time as a set of geographical coordinates: what you do in the Colorado Rockies doesn't really have an effect on New York. Why should it?

Note this is how actual time travel is theorized to work.

So more like a big Ball of wibbly wobbly timey wimey stuff... (http://www.youtube.com/watch?v=vY_Ry8J_jdw)?

:smallbiggrin: Couldn't help myself.
The time travel I've stuck in my campaign tends to be the "Ah something is now changed so we are an alternate universe now" style because if the PC's are able to change something then trying to have had it ALREADY happen is hard.

Though my advise for one big old time loop where they go back and do an event that you've already told them was done (even if they don't know they did it) E.g "The first time BBEG was defeated 2145 years ago was by a group of strangers with odd clothes and accents" is to make sure you are vague on the details of the past... If it is history how accurate is that history. If BBEG was historically killed by a single sword strike from Bob The Mighty then the time traveling PC's HAVE to kill BtM with one blow or you get a bunch of paradox type things.

In any event time travel in D&D is what you say it is :smallbiggrin: though I warn you now that if your group are big fans of Science Fiction then they might strongly disagree with ANYTHING you do:smallbiggrin::smalltongue:

[hiryuu]

In any event time travel in D&D is what you say it is :smallbiggrin:

THIS. USE THEM AAAAAALL


though I warn you now that if your group are big fans of Science Fiction then they might strongly disagree with ANYTHING you do:smallbiggrin::smalltongue:

Yeah. I run a game with a physicist, an optical engineer, and a honest-to-real-life siege technician (literally. He rebuilds ancient technologies and siege weapons and then plays with them, that is his job). You can't imagine what I have to prepare for, and Pun-pun is small cookies compared to what these people will do with tongs, two rocks, a potato, and a copper piece.

Don't mind me, I'm just disappointed that time travel's most ironclad (currently theorized) rule is "What happens in Vegas stays in Vegas."

[NichG]

There's rooms for lots of time travel models and all have their downsides.

Alternate universe-based time travel breaks conservation of energy, which sounds abstract and immaterial to actual game play until you realize that it can also be used to duplicate items. It also leads down a slightly dark philosophical path of 'does anything we do matter? When we change things in the past, that horrible future still exists in another timeline - we're just trying to find a good home for ourselves, but its fundamentally selfish'.

Self-consistent time loops are really hard to run in any way that players would be remotely familiar with. You basically have to railroad things pretty harshly, or whenever time-travel is involved you have to ask the players in advance 'okay, we won't play this out, but tell me about the self-consistent loop you author' which is awkward.

Total lack of causal relationships basically means the only reason to time travel is to obtain information or material from the past. This also breaks conservation of energy.

My suggestion would be to not try to make a time travel model that a physicist would come up with, but make one that a game designer or writer would come up with. For instance:

- There is a rare substance known as Wellsite, which grounds an object in time and protects it against the effects of Paradox, an energy released when time changes that either enacts the changes or reverts things to the way they were based on the path of least resistance - this includes trying to do such things as maintaining universal conservation laws. An object imbued with Wellsite is partially protected from Paradox, though the more this protection is stressed, the higher the rate at which the Wellsite is used up. Time travelers in particular can only safely operate when protected with Wellsite; this is tricky because, due to its nature, Wellsite cannot travel through time. As such, travelers can only journey to known Wellsite nodes, which are slowly tapped out the more that travelers go there. If a traveler wants to bring back material from the past, they must similarly return to a Wellsite node where it can be imbued.

Certain historically important events have been reinforced by Wellsite. They cannot be changed unless their node is taken out first. This is the reason that if you assassinate Hitler as a child, someone else will take his place and WWII will still happen - because there is a Wellsite node under Hiroshima that is preserving the bombing as a fixed point in history.

You could do a lot with a system like that - unprotected things are basically altered willy-nilly as you need them to be as a DM, because events are following a path of least resistance to ensure that all the Wellsite-protected fixed points happen like they should. Players can't trivially duplicate objects or time-travel as they'd like, because they have a limited Wellsite quota (this acts as currency in the far future, where certain nodes have been staked out and are parcelled out to chrononauts). If they want to duplicate an artifact, they can - it just costs them a certain amount of Wellsite.

Also there's a doom scenario when all the Wellsite in the world is used up, and Paradox thinks its easier to create a self-consistent history where the world never evolved life in the first place, and so time-travel was never discovered. Enough to make people nervous when they measure that the ambient levels of Paradox are increasing on everything.