I have seen similar questions about groundhog day but they were about either a single unique groundhog day or a permanent one.

In this case, each day may or may not repeat. There are no limits so you could have one whole month without repeating followed by the same day repeating ten times. As in the standard groundhog, everyone remembers what happened but everything reverts to the way it was before at midnight.

That means that if the 3rd December is a looping day, at 23h59 you will suddenly be where you were at 0 AM. You will remember everything you did and so will everyone else, but the state of the world will be reverted back. If someone died they will be back, items that were created will disappear, computers will have the same data they held back then, etc.

Everyone remembers every single loop so if a day repeats three times, people will remember the three days of "false/erase" memories. The world has always been that way and it's common knowledge.

Suppose a world similar to our own but that has those random looping. I'm wondering how the legal system would deal with it. I have seen several problems that this would cause:

  • If someone is arrested right away and there is a loop they realise they shouldn't have done this now and don't. The officers who arrested him could testify but that raises the issues of police framing people very easily and also the question of whether someone whose crime was erased should have the same punishment as someone whose crime stuck.

  • If a looping happen during a trial, would they have to represent the same evidence they already did and hear the same witnesses again, would the jury have to redo their verdicts several times in a row if needed? Furthermore , knowing what happened the previous day would probably affect how the questions to the witnesses would go.

  • There would probably also be huge issues with contracts.

For me this seems like a lose-lose situation. You either end up relying on memories and have to fully trust memory witnesses, have incomplete trial records and a hard time checking in the future (even 10 years later, who will remember all the details).

On the other hand, if you want to have records, you have to redo similar things again and again which might influence the results (bored juries, police wasting a lot of time trying to confirm if someone will "recidive", etc.).

What would be a "fair" system that allows appeal and suffer the minimum disruption from looping?


closed as too broad by Cyn says make Monica whole, We are Monica., Alexander, jdunlop, Giter Feb 16 at 1:51

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • $\begingroup$ Welcome to Worldbuilding, Akina! If you have a moment, please take the tour and visit the help center to learn more about the site. You may also find Worldbuilding Meta and The Sandbox useful. Here is a meta post on the culture and style of Worldbuilding.SE, just to help you understand our scope and methods, and how we do things here. Have fun! $\endgroup$ – Gryphon - Reinstate Monica Feb 15 at 22:41
  • $\begingroup$ Hi Akina, I'm trying hard to figure out the internal logic of your world and it seems to me that the complexities are quite astounding. +1 . But I fear that it's too broad and opinion based. Which criterion will get the question closed first is a coin throw in this loop. $\endgroup$ – We are Monica. Feb 15 at 23:19
  • $\begingroup$ If people's memories are left intact, then what would stop someone from using a biological brain-esque form of data storage? $\endgroup$ – Bewilderer Feb 15 at 23:40
  • $\begingroup$ Hi Akina, do you mean a "Groundhog day for everyone" in a single shared universe, not personal multiverse? $\endgroup$ – Alexander Feb 16 at 0:00
  • $\begingroup$ Hi. I mean a groundhog day for everyone,in a shared universe. Everyone is aware that the looping are happening, and when they happen, they happen to everyone at the same time. As for brain like computer to store data, I would assume they wouldn't be advanced enough for this to be a workable solution yet (though I assume that field would be way more active in that world than in ours). $\endgroup$ – Akina Feb 16 at 0:06

This concept is intriguing.

I have a potential answer, but it depends on a lot of assumptions that are not clarified in the question, and they are too extensive to handle in the comments.

First, I am assuming that there is a philosophical difference between the mind and the body. That is, the mind exists independent of, but reliant upon, the existence of the body.

"Life', or the physical body part, is like a virtual reality game that the 'mind' part is playing, only every human is collectively part of the game. Just like a game, a 'save point' can be set, and the game continues, but if things do not go as expected, the player can reload the game as 'frozen' by the save point, and continue on. The player's mind, of course, remembers everything that happened the first time around, and can use that information to make modifications in her play so that this time around things will go differently. Except that, since it is a multi[player game, no one player can decide to go back to the save point. This option happens randomly, and beyond any player control.

Another difference is, the player's mind and the body are intricately linked, so the mind has no other body, and the body has no other mind (the game avatar is, in fact, part and parcel of the mind).

Another consideration is that the save point is always 24 hours (sort of like one 'turn'). You can not go back 48 hours, or 72 hours, or one week. Whatever happened up until 24 hours ago is unchangeable. It can not be redone. If you were falling off a cliff at the save point, you are falling at the same rate when the game is reset.

Another assumption - that the society has ALWAYS been this way, since 'creation', whatever form that takes.

Also, that everything physical gets reset - all of the laws of physics and all of the equations of physics, chemistry, and cosmology go back to exactly the same numbers, values, coordinates, states, that they were at reset. The physical body world is reset, but not the ephemeral mind part of the mind-body duality. The mind retains all of the experiences, memories, skills, wisdom. and knowledge gained.

If my analogy and assumptions are correct, if this is your world, read on. If not, I suppose this answer can be deleted.

In this scenario, a mistake that a person makes is not always final. If they mess up, there is a chance to re-play part of their life - one complete day's worth. But they can not depend on this. They can not plan on it happening. If they mess up, and the game gets reset to the last save, bonus for them. A second chance. If the game does not get reset, they are stuck with their decisions.

So if, for a crude example, one is married and decides to go on a hall pass, and has absolutely great mind-blowing sex with a stranger, but ends up with a communicable disease, if the day is reset they have the absolutely exquisite memory but not the consequences - they no longer have the disease. But they can not COUNT on the day being reset.

This happens even if something GOOD happens. That is, if they win a lottery and are set for life financially, and the day is reset, they can lose the lottery the next time around. Random chance is random, even between iterations.


The legal system by necessity would have to have as its basic tenet 'most recent most legal'. That is, the only thing that would be considered is the state of the world at the end of the latest iteration. Just like the end of a virtual reality game depends on the most current iteration, not on what happened in the iteration before the reset. You win or lose the game AT THE END, not in the middle. Some players that were winning, end up losing; some who were losing end up winning; but the only thing that matters is how the game ends.

There is no such thing as fair or unfair in life - things happen. Upsets happen. It gives, and it takes away. The only thing that really counts is how it is played out until the end, and the memories, skills, wisdom, knowledge, isight you gain along the way.


Looked at from another angle, our legal system is based entirely on causality. We did something that caused something else to happen. Everything is sequential.

Consider the following argument in a court of law:

"You woke up this morning and you visited your ex-spouse, you got in an argument with her, and you killed her. You had great remorse for what you did. So when you got up this morning, you remembered the consequences of you going to see your ex-wife later in the day, and you decided not to visit her. So you did not kill her. So when you woke up this morning, the consequences of your actions later on in the day caused you to do something different in the past, so your wife is not dead."

Where is the chain of causality? The act of killing her lead to you not doing something that lead to you not killing her.

The only arguably legally pertinent 'causality' chain is the most recent one. You did not kill her, therefore you are not responsible for nor did you cause her death.

  • $\begingroup$ In the end, considering the final state when a looping day end and ignoring everything that was erased does seems like the simplest solution. $\endgroup$ – Akina Feb 17 at 11:47
  • $\begingroup$ Otherwise you are looking at contradictions in causality. If I do something during the day that goes badly, the day 'loops' back the the beginning and I start all over, and because of my 'memories' of what happened IN THE FUTURE, and I change my tactics, has the future CAUSED my actions IN THE PAST (the beginning of the new iteration)? Can causality go in the reverse direction? Can the future cause the past? phys.org/news/… $\endgroup$ – Justin Thyme the Second Feb 18 at 18:23

It's worth noting that in most depictions of a Groundhog Day loop (including the one in the eponymous film), only one or a small group of people can remember what happened. You seem to be assuming that everyone in the loop remembers, so I'll answer under that assumption (your world; your rules).

Starting with the last:


If a contract has physical requirements, including money, then the person has to make sure they are in compliance after the groundhog loop ends. Requiring compliance within the loop seems problematic, as it seems likely that people will get tired of repeating the same actions for no result.

The most natural thing might be to make groundhog days into business holidays. Because until the last day, the actions don't really count. Most contracts would explicitly handle issues like loops, because they would be expected. It would be natural to push out the deadline if a loop holiday prevented the delivery date.

The only event within the loop that would be controlled by contract would be those enforcing secrecy. A loop would not obviate the need to keep information private. Because information transfers are the only thing that can persist past the loop.


The first day, they would have to hold the trial. Because they don't know that they'll loop (at least as I understand your rules). But I suspect that they would call it off for the remaining days of the loop. Because they wouldn't be able to keep any of the physical records from the day.

I suspect that you are correct that they would have to redo that first day. Yes, it may disrupt the trial. To reduce the impact of that, trials may concentrate more on affidavits and less on direct testimony. The reason being that it is easier to redo an affidavit than a cross examination.

Erased crimes

It would make sense for property crimes to only count on the last day, when they actually take effect. Because that's the only day when someone actually loses the property. But violent crimes should be illegal whenever. Because the trauma from, for example, rape, is more mental than physical.

They may get prosecuted less, as it might be harder to gather evidence. But such crimes should stay criminal. And it's not like there aren't crimes prosecuted purely on witness testimony now. Such prosecutions are possible albeit more difficult.

  • $\begingroup$ Most of this assumes they KNOW they are going to loop again, and that they KNOW when and what the 'last loop' is going to be. $\endgroup$ – Justin Thyme the Second Feb 16 at 1:05
  • $\begingroup$ @JustinThymetheSecond I read it as everything is repeated on the day after the loop ends. So for a trail, it's held as normal. Then they discover it's a loop, so it's auto-postponed. Once the loop ends (Which is fairly obvious with any sort of mechanical or electronic datekeeping), it's time to go back to trial. $\endgroup$ – Andon Feb 16 at 1:09
  • $\begingroup$ @Andon Okay, I get it, First loop counts, all others are ignored. Interesting take. But what happens if you die in the third loop? $\endgroup$ – Justin Thyme the Second Feb 16 at 1:14
  • $\begingroup$ @JustinThymetheSecond Your world. Your rules. What does happen if you die in the third loop? Wouldn't you just come back to life in the next loop? That was my assumption when writing the answer. And yes, I'm assuming that you know when the loop is over even though you don't know when the loop starts. I.e. the first iteration of the loop looks like a normal day. Subsequent iterations are easily recognizable. It would be on the news. "Hey folks, astronomers tell us that we're in another loop. So just take the day off. We're going to put the station on automatic and go home." $\endgroup$ – Brythan Feb 16 at 1:19
  • $\begingroup$ @Brythan Okay, it makes sense, except that if the third loop were the last loop, and you did NOT go back to the beginning of the day again, wouldn't you stay dead? i had sort of assumed hat it was the LAST iteration of the day that counted, not the first. And that randomness was random between iterations. $\endgroup$ – Justin Thyme the Second Feb 16 at 1:28

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