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Old 10-10-2017, 09:45 PM   #1
Michael Thayne
 
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Default Temporal paradox rules

Recently, I've skimmed the rule books for two time-travel RPGs, Continuum and TimeWatch, and am thinking about trying to come up with broadly similar, setting-independent rules for GURPS, more likely hewing closer to the TimeWatch rules (because they're more setting-independent to begin with). I'm curious if anyone has ever attempted something similar before.

What the systems have in common is that in both systems, temporal paradoxes are bad but not the end of the universe, insofar as you only go *poof* if you get caught in multiple temporal paradoxes in a row without fixing the damage. Furthermore, the damage from temporal paradoxes tends to get resolved eventually, one way or another. Think the first Back to the Future movie: Marty can screw up his parents' meeting, and this is bad, but he has a chance to fix the damage he did.

In Continuum, other time travels will fix your paradoxes ("frag", in the game's in-universe jargon) if you don't, and may be quite annoyed at you for not cleaning them up yourself. Fixing paradoxes always requires putting back the timeline as it originally was, or as close to the way it originally was that no one can tell the difference. One reason I'm not thrilled about adapting Continuum to GURPS is that the setting ultimately depends on the existence of all-powerful transhumans from the future who will fix temporal paradoxes no one else can.

TimeWatch, a more lighthearted game, lets you automatically heal the effects of temporal paradoxes ("chronal stability loss", in TimeWatch's jargon) in-between adventures, and allows a certain amount of temporal paradox first aid, so to speak, mid-adventure via your fellow PCs reminding you who you are. (Because the premise is you're hanging on to your ontological status through sheer force of will.) Thus, unlike Continuum, it's fine for paradoxical things to happen and never get resolved in a logical fashion—as long as too many don't occur in a single adventure.

I wrote up some notes on a loose conversion of TimeWatch to GURPS which I'm going to post later in the thread. But I want a clear break, where I can ask: does anyone know of anyone doing this in GURPS?
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Old 10-10-2017, 09:49 PM   #2
Michael Thayne
 
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Default Re: Temporal paradox rules

My notes on converting TimeWatch to GURPS: under these rules, everyone has a new secondary characteristic, Chronal Stability Points (SP), the base value of which is equal to Will. Can be raised as high as Will×2 or lowered as low as Will/2 for ±1 point per level. The option of buying or selling off SP replaces traits like Temporal Inertia and Unique.

At less than ⅓ of your SP left, you take a -1 penalty to all attribute at skill rolls. At 0 SP, you take a -2 penalty to all attribute and skill rolls, and a -1 penalty to all active defenses. At -1×SP, the universe tries to fix the temporal paradox you represent, by turning you into a native of the current timeline—but your friends can still rescue you and you will gradually recover as below. However, once you've dropped to -1×SP, 1 point of SP loss will be permanent (until you spend a character point to buy SP back up). At -2×SP, you are erased from existence, and in fact never existed. Even your time-traveller friends won’t remember you, and any good you done over your life will be undone.

Every instance of time travel costs 1d-2 SP, minimum 0. In games that use destiny points, wildcard bonus points, or allow spending character points to affect the outcome of rolls, you can spend 1 point in advance of the roll to avert this. Wildcard bonus points can only be spent in this way if they come from a thematically-appropriate wildcard skill. Psychologist! counts as “thematically appropriate” for this purpose.

If you actually experience something that contradicts events you already know about, you’ll lose more SP—at least 1d SP, but possibly 2d or more (GM’s discretion) for, say, travelling back in time and doing something that eliminates your original reason for travelling back in time, or killing someone essential to history.

If you’re in a timeline other than the one you were originally born in, add 2 to any SP loss, i.e. 1d SP for any instance of time travel and at least 1d+2 SP for any paradox. The GM may waive this penalty if a character takes up long-term residence in a new timeline.

You regain SP at a rate of 1 per day. This requires spending time socializing with friends and family to remind you who you are. When under the care someone with Psychology (Clinical), the caregiver can roll once per day to enable you to regain 1 additional SP. Cinematic time-travel campaigns might allow for faster recovery of SP, including but not limited to rolling against Psychology at a big penalty to help allies regain SP instantly (this "cinematic" option is meant to model something that's actually a core mechanic of the original TimeWatch).
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Old 10-10-2017, 10:12 PM   #3
Kelly Pedersen
 
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Default Re: Temporal paradox rules

It's definitely an interesting idea! Since the Stability Points work like hit points, you can probably adopt a number of traits that modify HP to work with these as well. For example, rather than dumping Unique and Temporal Inertia, you could make them work like Unhealing and Rapid Healing for SP, respectively. In the case of Unique, I'd treat it like the lower, Partial level of Unhealing - you don't heal SP except in special circumstances, specifically only when you've restored your personal timeline to a state you can "exist" in.

I'd suggest that an interesting way of dealing with SP loss would be to treat large hits (say, half your SP total or more) as crippling injuries, except that what gets "crippled" are your various traits relating to your connection to the world. So, take 5 SP? Bam, suddenly you never made those good investments all those years ago, and you've lost a level of Wealth.
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Old 10-10-2017, 11:59 PM   #4
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Default Re: Temporal paradox rules

For time travel in my GURPS games, I use the very simplified version in GURPS Casey & Andy (based on the webcomic of the same name, which has several time-traveling characters and at least one time-travel story arc from which the book takes its cue). A good overall "mad science" strip (now finished with strip #666) and the GURPS book takes its cue from that. (Oh, and the strip was by Andy Weir, the guy who wrote The Martian, so the science isn't as blatantly wrong as the term "mad science" can convey.)

In short, if you screw something up, you end up in an alternate universe with no way to get back to your 'home' timeline until you go back and fix it... and even then there's a possible chance that something went wrong anyway which puts you into a third timeline instead. You can eventually fix things, of course, as the Laws of Drama and the GM permit. :)
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Old 10-11-2017, 12:06 AM   #5
Kelly Pedersen
 
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Default Re: Temporal paradox rules

Here's another thought - you could create a "Costs Stability Points" limitation (I'd price it the same as Costs HP, -10% per SP using the ability costs), and give players the option of taking various appropriate advantages - things like Serendipity, Luck, and other "meta" advantages - that would represent manipulating the timestream to their advantage, at the cost of possible paradox.
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Old 10-11-2017, 07:34 AM   #6
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Default Re: Temporal paradox rules

I dunno anything about TimeWatch, but I know lots about Continuum.

Running the Continuum setting in GURPS would be extremely easy. Don't bother trying to reproduce the ability to span in GURPS rules—it's a built-in ability that all player-characters have (and has far more absolutes than GURPS is comfortable with). So just hand-wave that Span Ones can span with Span 1; Span Twos can span with Span 2, and so on. Then introduce "Continuum Rank," which is equal to your Span, so a starting character has Continuum Rank 1. Most Novices also start in a Novice Corner, with their Mentor as a Patron. There is no need to assign a disadvantage to follow the Maxims; the punishment for not following them is in the bad things that naturally follow from ignoring them.

Run Time Combat exactly as described in the Continuum rulebook, Stratagems and all. The only special thing you need for GURPS is to describe what happens to you when you get fragged. Each point of frag should count as a point of Fatigue and a -1 penalty to all rolls. Starting at frag 6, the character also gains -10 or so points of temporary disadvantages like Distinctive Features and Disturbing Voice, to represent the weird fading-in-and-out effects of high frag; they also gain Insubstantiality with the Uncontrollable limitation. As usual, if you get more than 7 points of frag, your character becomes an NPC.

Aside from the effects of frag, there are no special rules regarding paradoxes. Either you resolve them or someone else does, whichever side of the As/As Not you're on, because an unresolved paradox would eventually tear apart the whole universe, and since the universe is demonstrably here, it is known that that doesn't happen.

Otherwise, everything is straightforward GURPS. Tech Levels become very important to keep track of, and the scopes of your Area Knowledge skills must be carefully specified both spatially and temporally. Most loyal spanners will have a Sense of Duty to either their chronies or the Continuum, but this is not required. Higher-span characters will usually have a Duty to their Fraternity. Novice spanners don't have the breadth that higher-span characters do, but they'll still encounter lots of them, so these things will be important right away.
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Old 10-11-2017, 07:48 AM   #7
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Default Re: Temporal paradox rules

Oh, you might want to drop the wealth rules too, and just let characters have whatever they want. The Moneychangers Fraternity manages their finances for them, so they don't try to get rich playing the stock market and such and end up fragging people. All characters would have some number of levels of Multimillionaire. So there's really little point in tracking money or economic status.

Status (among levelers) becomes a matter of personal choice for the spanner. You might want to let them have any level of it to match their chosen lifestyle, for free, unless they live in a society in which Status can't be bought.
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Old 10-11-2017, 09:20 AM   #8
Michael Thayne
 
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Default Re: Temporal paradox rules

Quote:
Originally Posted by Kelly Pedersen View Post
It's definitely an interesting idea! Since the Stability Points work like hit points, you can probably adopt a number of traits that modify HP to work with these as well. For example, rather than dumping Unique and Temporal Inertia, you could make them work like Unhealing and Rapid Healing for SP, respectively. In the case of Unique, I'd treat it like the lower, Partial level of Unhealing - you don't heal SP except in special circumstances, specifically only when you've restored your personal timeline to a state you can "exist" in.
Another thought I had was to treat them like Fragile and Unkillable. For Unique, you go "poof" at -1×SP. For Temporal Inertia, the normal effects of -1×SP are as bad as it gets—though if a player tries to abuse this, the GM can rule that each multiple of SP makes the PC increasingly unplayable and/or useless to the party.

Quote:
Originally Posted by Phantasm View Post
For time travel in my GURPS games, I use the very simplified version in GURPS Casey & Andy (based on the webcomic of the same name, which has several time-traveling characters and at least one time-travel story arc from which the book takes its cue). A good overall "mad science" strip (now finished with strip #666) and the GURPS book takes its cue from that. (Oh, and the strip was by Andy Weir, the guy who wrote The Martian, so the science isn't as blatantly wrong as the term "mad science" can convey.)

In short, if you screw something up, you end up in an alternate universe with no way to get back to your 'home' timeline until you go back and fix it... and even then there's a possible chance that something went wrong anyway which puts you into a third timeline instead. You can eventually fix things, of course, as the Laws of Drama and the GM permit. :)
Oh, I forgot about GURPS Casey & Andy. I need to go back and look at that supplement. Thanks!
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Old 10-11-2017, 09:21 AM   #9
Michael Thayne
 
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Default Re: Temporal paradox rules

Another thought I had: build something on top of the corruption rules from GURPS Horror. Each time a time-travelling PC messes with time, the GM should ask themselves, "what would the ability to repeatedly pull this stunt cost as an advantage?" The PC then takes "paradox" (basically corruption) equal to 1/5th of this point cost.

Paradox can convert to negative character points much as corruption does, except that instead of converting to "evil" disadvantages, it converts to Amnesia, Delusions, Flashbacks, or meta-disadvantages that represent the universe trying to erase the character from existence, such as disadvantageous Destiny, Unluckiness, or if the PC really screws up, Cursed.

Trying to add points to someone's character sheet is generally going to cause someone paradox equal to at least 10×CP added. Cheating death, or going back in time to prevent a death you know about, will inflict a full 250 points of paradox, again at a minimum (since Extra Life is worth 25 points).

This also acts as a sort of "upper limit" on how much a single act of time travel can screw with an enemy: at worst, you kill them or prevent their birth, which doesn't erase them in the original timeline but does inflict the 250 points of paradox that they would get from cheating death. In effect, you kill them but they automatically cheat death in reaction.

If you do something that creates a wide-ranging paradox, take additional paradox equal to the lesser of the following two values: either 1 point of paradox for every person affected, or look up half the longest dimension of the area affected on the Speed/Range table, and take paradox equal to the listed penalty.

In this system, the "meritorious acts" of the base corruption system are replaced with fixing things so that the paradox turns out to be only apparent: rescue someone you "know" died, but then fake all the evidence of their death you knew about when you decided to rescue them.

ETA: You'd also need to replace the -1 in reactions from "saintly or divine beings" with -1 in reactions from those opposed to mucking about with Time.

Last edited by Michael Thayne; 10-11-2017 at 09:30 AM.
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Old 10-11-2017, 11:55 AM   #10
Michael Thayne
 
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Default Re: Temporal paradox rules

Looking at the Casey & Andy time-travel rules, there's something to be said for them, but the badness of paradoxes sort of depends on a time-traveler caring about returning to his or her original timeline. If they don't care, there's not much to stop them from creating all kinds of temporal mayhem. The GM can try to make them there by having every change be a disaster, but this can strain plausibility eventually. Not all campaigns care about a veneer of plausibility, but it's an issue for ones that do.
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