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View Full Version : DM Help Implementing time loops?



Silus
2017-03-12, 07:06 AM
Okay so I admit I just got finished playing Oxenfree (A wonderful spooky kinda game on Steam ya'll should totes play) and I got to wondering, how would a DM implement time loops in a tabletop game?

For this I'm thinking less Groundhog Day and more short term, like the last 10-15 minutes looping, or time looping back to a certain point upon passing a threshold (Sort of like a trap). Also for this, assume that the PCs are aware that they are stuck in a time loop but NPCs are unaware.

So, how would ya'll handle it? Or would you instead opt to not touch such things with a 10 foot pole?

Frozen_Feet
2017-03-12, 09:52 AM
Depends on the nature of the loop.

If it's a hard reset, with everything being restored to how it was with the exception of player knowledge, the implementation is dead easy. You only need to memorize the initial state and go back to it at whatever interval you desire.

Time loops only become hard when they're closed. Now you have to pay special attention to player action and potentially limit player freedom to avoid Grandfather Paradoxes.

You can dodge most paradoxes via multiversal time travel. That is, each new iteration of the "loop" (which is really a spiral) is a new branch of the timeline, with unidirectional causality: what happens in the new iteration won't influence the earlier ones.

If the above is confusing, think of the following examples:

Groundhog day is hard reset. Only the main character's knowledge is preserved - otherwise, no events of earlier iterations affect newer ones. No paradoxes are possible.

The first Terminator movie, in isolation, is a single timeline, closed loop. The attempt to go back in time to avert future events, causes them. As long as variation is minimal or not allowed, it is Paradox free. But wait! What if players play many loops and decide to do something differently? Like, Kyle doesn't have sex with Sarah? Well, now you're in trouble, because without that event, Kyle couldn't be there to begin with. So now you, as a GM, will have to conspire to make it happen, or you have a paradox.

Terminator franchise from Judgement Day onwards operates on iterative multiversal time travel. That is: once, there was a timeline 0 where John Connor was not fathered by Kyle Reese and Skynet came to being without researchers having access to the Terminator's remains. Then Skynet created Timeline 1, where it tries to assassinate Sarah and Kyle saves her. Later in either Timeline 0 or 1, Skynet realizes it is still losing, and creates Timeline 2 by trying to assassinate John as a kid... so on and so forth.

Notice that either/or. It is not given any of the timelines get erased as new ones are created. It is possible they continue to exist and progress. This would explain why in Terminator: Genisys there are so many terminators at the same point of time - they come from different timelines. By my count, this means at least 7 parallel universes exist and influence each other. If this sounds complex, that's because it is.

Another franchise with iterative multiversal timetravel is Dragon Ball.

Then there is Legend of Zelda, which has multiple timeloops in the same setting yet all obeying different rules. The rules of time travel aren't usually consistent even within a game, see Oracle of Ages for a case study. Amusingly enough, this doesn't prevent the time travel puzzles from being legible to players. The nonsense only becomes obvious when you try to put them all together.

Mutazoia
2017-03-15, 03:58 AM
Depends on the nature of the loop.

If it's a hard reset, with everything being restored to how it was with the exception of player knowledge, the implementation is dead easy. You only need to memorize the initial state and go back to it at whatever interval you desire.

Time loops only become hard when they're closed. Now you have to pay special attention to player action and potentially limit player freedom to avoid Grandfather Paradoxes.

You can dodge most paradoxes via multiversal time travel. That is, each new iteration of the "loop" (which is really a spiral) is a new branch of the timeline, with unidirectional causality: what happens in the new iteration won't influence the earlier ones.

If the above is confusing, think of the following examples:

Groundhog day is hard reset. Only the main character's knowledge is preserved - otherwise, no events of earlier iterations affect newer ones. No paradoxes are possible.

The first Terminator movie, in isolation, is a single timeline, closed loop. The attempt to go back in time to avert future events, causes them. As long as variation is minimal or not allowed, it is Paradox free. But wait! What if players play many loops and decide to do something differently? Like, Kyle doesn't have sex with Sarah? Well, now you're in trouble, because without that event, Kyle couldn't be there to begin with. So now you, as a GM, will have to conspire to make it happen, or you have a paradox.

Terminator franchise from Judgement Day onwards operates on iterative multiversal time travel. That is: once, there was a timeline 0 where John Connor was not fathered by Kyle Reese and Skynet came to being without researchers having access to the Terminator's remains. Then Skynet created Timeline 1, where it tries to assassinate Sarah and Kyle saves her. Later in either Timeline 0 or 1, Skynet realizes it is still losing, and creates Timeline 2 by trying to assassinate John as a kid... so on and so forth.

Notice that either/or. It is not given any of the timelines get erased as new ones are created. It is possible they continue to exist and progress. This would explain why in Terminator: Genisys there are so many terminators at the same point of time - they come from different timelines. By my count, this means at least 7 parallel universes exist and influence each other. If this sounds complex, that's because it is.

Another franchise with iterative multiversal timetravel is Dragon Ball.

Then there is Legend of Zelda, which has multiple timeloops in the same setting yet all obeying different rules. The rules of time travel aren't usually consistent even within a game, see Oracle of Ages for a case study. Amusingly enough, this doesn't prevent the time travel puzzles from being legible to players. The nonsense only becomes obvious when you try to put them all together.

Another good example of a closed loop would be H.G. Wells "Time Machine", wherein the main characters wife dies. In his grief he invents a time machine to go back in time and save her life, and failing each time, he fails to reailze that her death directly causes the invention of the time machine. Therefore if he prevents her death, he has no reason to invent the time machine, so the time machine doesn't get invented, so she dies...so he invents the time machine and saves her...and doesn't have a reason to invent the time machine, so she dies.... You get the picture.

In order to prevent this paradox, "the universe" simply makes sure she dies, no matter what. Her death, like Sean Bean characters, are a fixed point in time.

You are probably going to have to run a "Ground Hog Day" style time loop, since you are not going to be able to erase the knowlege of what did/will happen from your player's minds (with out copius amounts of alcohol and/or repeated blows to the head). Unfortunately, only in fiction do the characters not realize they have been living the same moment over and over for the past two-thousand years.

Silus
2017-03-16, 02:51 PM
Another good example of a closed loop would be H.G. Wells "Time Machine", wherein the main characters wife dies. In his grief he invents a time machine to go back in time and save her life, and failing each time, he fails to reailze that her death directly causes the invention of the time machine. Therefore if he prevents her death, he has no reason to invent the time machine, so the time machine doesn't get invented, so she dies...so he invents the time machine and saves her...and doesn't have a reason to invent the time machine, so she dies.... You get the picture.

In order to prevent this paradox, "the universe" simply makes sure she dies, no matter what. Her death, like Sean Bean characters, are a fixed point in time.

You are probably going to have to run a "Ground Hog Day" style time loop, since you are not going to be able to erase the knowlege of what did/will happen from your player's minds (with out copius amounts of alcohol and/or repeated blows to the head). Unfortunately, only in fiction do the characters not realize they have been living the same moment over and over for the past two-thousand years.

I think the route I'd be trying to go for is like a smaller version of Groundhog Day. Like the party is wandering through the woods and comes to a fork in the trail. Their NPC guide (or whatever) says...something, either direction-wise or just chatting with the PCs. The PCs start making their way down one trail, cue electro-static interference/magical hoodoo/old-school scene transition and all the PCs are right back at the fork in the trail and the NPC is finishing saying whatever he was saying for the second time.

Then it's a matter of trying to sort out how to escape the time loop (Like finding what doesn't belong or killing a sneaky beast or something).