Hi, everyone.

I'm on the process of designing a time-traveling RPG. Basically, the PCs are time-cops who use Matrix style fighting and Time witchraft to fight time-criminals and cults. On a 'high concept' level, it deals with changing timelines as a way of exploring what defines an individual, somehow like in Dark City: a search of what's essential and what is contingent.

The thing that's keeping me awake at nights are the laws of time travel. Conceptually, I need to find a way to make time travel interesting but not annoyingly so. I want this to be a game in where you can fall in love with your grandmother and killing your grandfather without creating a paradox. I also want to avoid the notion of going back again and again to the same point in time to redo a situation until it's right.

So, I would greatly appreciate any insight you might have on time travel that is 'logical' yet fun from a gaming perspective.

I recommend "The Man Who Folded Himself" as pretty much the best time travel story I've read; it doesn't have matrix-style fighting, but it does handle going back to the same time over and over again very well.

Basically, it sees the timeline as a tree; whenever you change history you add a branch to the tree. Anyone up the tree can move towards the trunk, but can only move up on one branch.

In game terms, if they try to do different things at the same time, the different versions of the characters don't all have the same information, and could end up fighting each other's interpretation of what's necessary. You might treat them as NPCs "with input from the original players", or something else.

In Men & Supermen, I suggested that GMs treat the timeline as more like a river: you can force a new fork, but its difficult, and the river's going to try very hard to get back together again afterwards. I didn't have game mechanics for this, but you could, of course. You could, for example, make it very easy to do things that restore two or more time tributaries (ambush their original selves and remove all record of the change from the timeline?), and harder to do things that alter the timeline more than once.

Jerry

Why would you want to remove the risk of creating a paradox? You could use the threat of paradoxes as reasons for time travelling. E.g. go back in time and stop your grandfather from being killed.

Make the game fun and people will probably overlook or at least forgive that it isn't entirely logical. After all, people read books and watch films with plots that are illogical and inconsistent, but that doesn't stop them from being enjoyable.

Thanks for the replies.

I'll go check out "The Man who Folded himself". I really liked the idea of timeline as a river. It sounds simple and elegant, yet it deals with a lot of the problems I had about time travel.

About paradoxes: I want to remove that risk because I don't want to avoid the feeling that the whole time continuum is on the brink of destruction all the time. Preventing your grandfather from getting killed sounds nice, but saving him form yourself is one of the things I want to avoid. Or at least, I want to avoid the idea of going back multiple times to save him, then the assassin going back multiple times to retry, etc...

I'm with you on the fun, but I want to make the time travel believable (with some 'suspension of disbelief'). I'm partial about making the game a future-noir-gritish kind of game or more like a dark-humor-Paranoia sort of play. Maybe it could accommodate both styles, but I would prefer if in both styles players had a sense of structure about time travel.

You might also want to check out a recent Game Chef entry:
http://www.somniturne.com/kon/causality2.0.pdf

It combines a bit of clones (a la Paranoia), a bit of GM switching (when a player causes a new time branch, he or she is that branch's GM), and some funky multi-character stuff (family, your clones, self-progeny).

David

How about having areas of time "harden" in response to repeated out-of-time intercession. Places in space-and-time have different levels of permeability (I'd recommend "GM's discretion" on this-- no sense integrating four-dimensional lookup tables into the system) based upon, in part, how often they or other time-travelers have been there-then. If this place/time has been visited before (often?), then the "shell" around it keeps later time-travelers from entering. For the purpose of sanity and expediency, let's just pretend that "later" is a mix of randomness and the order of happening in the story.

Anyone out of time attempting to visit a "hardened" area would be violently ejected to before, after, or geographically elsewhere. This would help the problem of replay loops, meeting yourself, and add a bit of puzzle to the whole works. You could also throw some gravel in the works by making these time-pockmarks randomly appear throughout the game. Travellers could be suddenly, lurchingly launched two days into the future while just walking down the not-their-time street.

As for paradoxes, I'd just keep it that you can't affect the memories or condition of anyone who stays in "real time" (or game-time) with you by altering their past, but events and situations themselves may have changed if you jump around.

I checked Causality. The setting looks good but the systems leaves me wanting. If it played like Cuban domino, the thing would make a lot more sense. However, the idea is the exact opposite of what I'm trying to achieve. Thanks for making me notice the entry, it helps me understand the things I don't want to happen.

Also, in answer to FLEB, I would prefer "GM discretion" to be left out of this aspect of the game, but I don't want tables either. I wnet over the time travel section of Feng Shui and it approaches more the way I wan't things handled. However, the specific probelm FLEB adresses is simply fudged, and I don't like that at all.

sabbatregent wrote:
The thing that's keeping me awake at nights are the laws of time travel. Conceptually, I need to find a way to make time travel interesting but not annoyingly so. I want this to be a game in where you can fall in love with your grandmother and killing your grandfather without creating a paradox.

I also want to avoid the notion of going back again and again to the same point in time to redo a situation until it's right.

I'd also recommend checking out Asimov's The End Of Eternity.

It has an interesting concept: Eternity, a large sort of institution that manipulates time for the (somewhat dubious) good of humanity, that has its institutions outside of our timeline.  However, there are still forces it has trouble working with, internal and external  It also has class ideas and everything.

http://en.wikipedia.org/wiki/The_End_of_Eternity

Maybe settle on the One Timeline At A Time ideology.  That is, whether or not there are multiple timelines, you can only easily go back and forth along your own, so if you become your own grampa then you your future is that which this is the case.  Travelling cross-timelines should probably be extremely difficult, dangerous, or require god-like skill.

How about the Dr. Who thing: When you directly involve yourself in an event, you cannot directly involve yourself in that event without creating a paradox.  If you want to change that event more than once, you have to find a different way of doing it.  (Eventually, long-lived time-travellers would end up being behind-the-scenes masters.)

I'd also recommend checking out Asimov's The End Of Eternity.

sabbatregent wrote: That gives me a great idea, that goes greatly with the river analogy. There is 'One True Timeline', call it fate, which is the way things are supposed to happen. My Time-cops would search attempts at deviating history form that fate, reverse them and catch the criminals.

....

Also, I would like to have a mechanical reason (that is, within the game rules) that prevents or greatly discourages going back to redo your actions. But yeah, I think Who has the best idea.

I suggest Connie Willis's "To Say Nothing of the Dog" and "Doomsday Book" for another example of time travel (and some fantastic fiction as well).  She uses sort of a variation on Lieber's Big Time concept; what we perceive as the time continuum is all happening simultaneously from a "higher" perspective that is not directly accessible.  The premise of these stories is that history is both  deterministic and dependent on individual action.

Having mentioned it, I highly recommend "The Big Time", by Fritz Lieber.  I also recommend, from a curiosity in different ways time travel might work perspective, the Company novels by Kage Baker.  I personally didn't like her writing style that much, but the ideas in those stories are completely fascinating.  See http://en.wikipedia.org/wiki/Dr._Zeus_Inc.

That reminds me of Douglas Adams' Whole Big Mish-Mash of Everything, Hans, where we're simply percieving events as we go, where time isn't just a number of distinct streams but an ocean.  Using the "Plural" concept (a place that is not congruent or consistent throughout time-possibilities) as all moments and you can make returning to a moment not necessarily the previous time they were there.  (Perhaps you need greater skill to hit the exact "depth".  Perhaps there is an inherent space-time drift that needs compensated for.)  WBMMoE is also very paradox-resistant.

I looked for a decent list of time travel tropes and found best to be the <a href="http://en.wikipedia.org/wiki/Time_travel">Wikipedia entry on time travel and if you want to get in-depth, there's the "Extensions of Conventional Models of Time Travel in Science Fiction" chapter in <a href="http://www.timetravel.110mb.com/">this thesis.  (Which I admit I've only skimmed, but it looks like a good stop in fictional time-travel research.)

Hmm, my post timed out when I tried to post it before, because the server wasn't letting me submit. Here it goes again...

The best system of time travel I've found is on this page, from the author of Multiverser, that originally appeared in that game. It does away with paradoxes entirely, unless you consider infinite loops paradoxes. The only problem that might not be so fun is how easy it is to create an infinite loop if you go back in time, which is pretty much "game over" as time gets locked in the cycle. I suppose it that the planning phase could be a large part of the gameplay: exactly how their actions will avoid such consequences.

I haven't read the book, but Multiverser apparently got around this problem by giving players what are essentially "lives," allowing them to take over an alternate universe version of themselves when they die or get trapped in a cycle.

Wow! I really was looking for an entirely different thing, but this timeloop idea seems great. My Timecops could travel through time both preventing and correcting this loops. If I could unite this idea with the 'Time as a river premise'... it could be exactly what I want.