I was thinking about the possibilties of a 'time-travelling investigation/exploration' type of game. People are able to travel through time, heck, maybe the setting is one where Wells's Time machine actually works and is mass produced. Business taps the earths untold mineral and fuel fuel reserves in the jurassic period, holiday-makers go on safaris in ages past, criminals go back or forward in time to escape capture and sell their goods. Cops chase them, private investigators speak to suspects before they carry out the crime. The possibilities are manyfold.

Now, what kind of mechanics would be needed to cover the possibility of changing the future or the past due to the PCs and NPCs actions, when they are elsewhere in time? Ripples in time that effect everything after the action, instant death for future generations of a family should their parents die in the past? Setting time straight?

Does anything already do this kind of stuff?

I think there was a TMNT supplement that included time travel.  Dinosaur characters and such.

Quote from: StuartI think there was a TMNT supplement that included time travel.  Dinosaur characters and such.

Any idea what it was called?

Mind you, i was thinking in terms of a turn of the 20th century game, with the focus on the people of that time expoiting this technology, rather than playing wierd stuff in other times. Still, lots of king kong type possibilities with hunters bringing smilodons and the like to the 1900's.  

I guess that would make it a 'time-travelling pulp' genre.

It doesn't have any mechanics, but I liked how Stephen King handled it in the Dark Tower series. The universe changes and nobody notices except those directly involved in the change, and they risk going insane as their brains try to hold two equally real yet incompatible pasts simultaneously.

Depending on what system you're using you can have them be mind screwed for a while and then make some sort of saving throw, resistance roll, or whatever. You can even make a fake roll yourself and let them recover. One bout of that should be enough to make them start thinking of ways to change things as little as possible but still achieve their goals.

Quote from: One Horse TownAny idea what it was called?

Mind you, i was thinking in terms of a turn of the 20th century game, with the focus on the people of that time expoiting this technology, rather than playing wierd stuff in other times. Still, lots of king kong type possibilities with hunters bringing smilodons and the like to the 1900's.  

I guess that would make it a 'time-travelling pulp' genre.

Transdimensional TMNT!!

Quote from: James McMurrayIt doesn't have any mechanics, but I liked how Stephen King handled it in the Dark Tower series. The universe changes and nobody notices except those directly involved in the change, and they risk going insane as their brains try to hold two equally real yet incompatible pasts simultaneously.

Depending on what system you're using you can have them be mind screwed for a while and then make some sort of saving throw, resistance roll, or whatever. You can even make a fake roll yourself and let them recover. One bout of that should be enough to make them start thinking of ways to change things as little as possible but still achieve their goals.

Hmm...interesting. I've got that series on my bookshelf, but have never got around to reading it. I think i'll see if it's got any ideas and if so, whether they would be transferrable to an RPG mechanic or not.

Actually, thinking about this, there's a possibilty for something along these lines to tie in with the Historical Cast products the guys are working on.

There was the book GURPS:TIME TRAVEL that was done for the 3rd edition of the game. They covered paradoxes, and also talked about "pulp" campagnms of the kind you describe.
 
 Much of that material was carried over into the GURPS:INFINITE WORLDS. While the front half is mostly that particular setting  - chapter 5 and chapter 8 deal with alternate and traditional ways of doing Time Travel for a roleplaying game.

- E.W.C.

Quote from: KoltarThere was the book GURPS:TIME TRAVEL that was done for the 3rd edition of the game. They covered paradoxes, and also talked about "pulp" campagnms of the kind you describe.
 
 Much of that material was carried over into the GURPS:INFINITE WORLDS. While the front half is mostly that particular setting  - chapter 5 and chapter 8 deal with alternate and traditional ways of doing Time Travel for a roleplaying game.

- E.W.C.

Thanks!

Quote from: One Horse TownHmm...interesting. I've got that series on my bookshelf, but have never got around to reading it. I think i'll see if it's got any ideas and if so, whether they would be transferrable to an RPG mechanic or not.

You only have to go as far as book two to hit the time travel paradox parts.

I've long wanted to run a time travel campaign in which the PCs go back in time to "fix" things. To keep it sane, I made the process very expensive and energy-intensive - so very few groups will travel. Paradox and such, I reasoned like this,

• Just as two objects cannot occupy the same space and go "smash" if they try, so too the same person cannot occupy the same time twice. No-one can travel to a time where they have already existed. If they try to, they go "smash."
• You can change history, and retain your own memories of the original history. But when you return, the changed world may not remember you, or may remember a different you.

So you can go back in time and shoot your maternal grandfather before he even meets your grandmother, but then when you zap back to your own time, you find that your mother doesn't exist and no-one knows who you are - your ID papers are considered to be excellent forgeries, etc.

You can go back in time and change history, but if on your return you find it gives you results you didn't like, then you can't go back to the same time again.

So for example you decide that the world would have been better without WWII and the Nazis, so you go back to 1918 and smother Corporal Hitler in his sickbed. Then you return to 2007 and find... The Weimar Republic staggered on until 1936 when Germany suffered civil war, and the communists took over Prussia and Saxony, while Bavaria declared independence and sought the protection of France, and Communist Prussia-Saxony and the Soviet Union allied in 1940 and invaded Poland, and... WWII ended with the USSR controlling all of Europe up to the Pyrenees, only British-allied fascist Spain holding out. The gulags swallowed forty million people.

"Hmmm, not a good result," you say, and since you can't go back to 1918 to stop yourself from smothering Hitler, you go back to 1880 and shoot Stalin while he's studying for the priesthood. Then you return to 2007 and find that in 1947 Chairman Trotsky united Europe under the red flag, and...

The back and forth, especially if there were a rival team of agents with different agendas, could be a fun campaign.

Why not run a time-travel game where there is no coherent theory of time? Technology has leaped ahead of physics and philosophy, and nobody's sure what exactly happens. Maybe they come back and things are different, maybe they spin off into a parallel universe (or maybe they just swap universes, and other versions of you end up in your home dimension). Maybe, maybe, maybe, but nobody knows jack shit for sure. Are the PCs going to completely fuck up the universe by shooting Hitler? Fucked if anyone knows.

Quote from: JimBobOzJust as two objects cannot occupy the same space and go "smash" if they try, so too the same person cannot occupy the same time twice. No-one can travel to a time where they have already existed. If they try to, they go "smash."

• You can change history, and retain your own memories of the original history. But when you return, the changed world may not remember you, or may remember a different you.

So you can go back in time and shoot your maternal grandfather before he even meets your grandmother, but then when you zap back to your own time, you find that your mother doesn't exist and no-one knows who you are - your ID papers are considered to be excellent forgeries, etc.

You can go back in time and change history, but if on your return you find it gives you results you didn't like, then you can't go back to the same time again.

So for example you decide that the world would have been better without WWII and the Nazis, so you go back to 1918 and smother Corporal Hitler in his sickbed. Then you return to 2007 and find... The Weimar Republic staggered on until 1936 when Germany suffered civil war, and the communists took over Prussia and Saxony, while Bavaria declared independence and sought the protection of France, and Communist Prussia-Saxony and the Soviet Union allied in 1940 and invaded Poland, and... WWII ended with the USSR controlling all of Europe up to the Pyrenees, only British-allied fascist Spain holding out. The gulags swallowed forty million people.

"Hmmm, not a good result," you say, and since you can't go back to 1918 to stop yourself from smothering Hitler, you go back to 1880 and shoot Stalin while he's studying for the priesthood. Then you return to 2007 and find that in 1947 Chairman Trotsky united Europe under the red flag, and...

The back and forth, especially if there were a rival team of agents with different agendas, could be a fun campaign.

Nice ideas. Thanks.

Quick pop quiz. Would anyone be interested in a system, or setting, based upon exploring periods in time? Sort of Dr.Who without the Doctor. This would be a nice excuse for people to snap up all of the Historical Cast products and get use from all of them during a single campaign (or series of campaigns).

I'm currently running a GURPS Time Travel campaign, using the following rules:

Characters are members of a "Time Corp" of temporal enforcers/time cops/whatever. They have the advantage : Temporal Inertia (as does everyone in the Corp - its how they recruit); this enables them to "remember" the "natural" timeline and notice any changes to it and then act to correct it. The Corp places ads in papers (or in my game, via Spam email) asking "Do you remember (insert a string of historical events here)? Ever wonder why nobody else does? Contact Mr. Williams at..."

The PCs clearly remember the events, which are not HUGE things people always talk about. When they start looking into it, they find out that indeed, they never happened. That's the Temporal Inertia. I used examples like the attempted Coup in the Soviet Union in 1992. Sure, it happened, but how often does it come up in day-to-day conversation?

Time is semi-changeable. Small changes even out over time - the universe WANTS to remain consistent - and as such don't need much in the way of correction. This allows you to wander around in the past without worrying about stepping on butterflies, for example. BIG changes can be affected by the proper application of force to certain places in the timestream. Preventing the assassination of Lincoln is much more complex than merely detaining Boothe - the Universe "wants" him dead, and will make it so, on the correct date and as much as possible by the correct person and method - unless a long string of changes can be brought about. These are the things the Time Corp is trying to prevent.

Like JimBob, no going back to any point in your life prior to your recruitment. This prevents paradoxes of meeting yourself. However, in my game, the universal tendency to keep things the same will prevent you from killing any of your direct ancestors, though "fate" or "luck" or just plain malfunctions of equipment. So you can't change the entire universe to where it dosn't remember you - that's part of the Temporal Inertia mentioned above.

Hope some of that helps.

http://www.aetherco.com/continuum/

Its had excellent reviews and one day I'll buy a copy. Probably yesterday.