Retcon the session, just this once
I empathise with your dilemma: the session itself is already immersion-damaging, but so would be retconning it. You can't win either way, so what's the path of least damage? Given the details you wrote, putting myself in your shoes as an immersion-centric player and GM, I would absolutely call for a one-time, exceptional-circumstances do-over.
The balance of issues
First, here are the elements of your question that I'm considering, pro and con, and how they're relevant:
- The player was extraordinarily off their game for exceptional reasons. Doesn't matter why—drunk, bereaved, recently traumatised—something happened that made out-of-game events entirely eclipse the continuity of the story you're exploring. As you say, the out-of-game situation was such that the session shouldn't have even happened, if you'd known.
- There wasn't much plot development outside of the uncharacteristic events. If you had a lot of other threads develop in the session then you'd have a knot to untangle if you decided to retcon, but you don't. That makes the situation much simpler.
- Your immersion is damaged by letting the session stand. There are lots of ways to weave the events into a coherent narrative using reveals of previously-unknown information. That's a considerable amount of work, and carries no guarantee that the immersion damage will be healed. After all, that stuff is being "written in" to explain something that you know happened for out-of-game reasons. Post facto justifications are of the same class as a retcon, actually, when it comes to their relationship to immersion and investment in story—both are editing the game's reality for out-of-game reasons and convenience.
- It's damaging to your players' immersion. This is the one point where I'm making an intuitive leap off the details you give, but here's why: You are running a certain kind of game, where the continuity and integrity of the story as an unfolding story is important, and that seems to be, from how you wrote about it in the question, a fairly integral part of your GMing style. If I can assume for the moment that this is an established group that has reached the stage of playing well together, your players have adjusted to and entwined their own playing styles and methods with your GMing style. If so, then they've come to trust the integrity of the story in a similar way, and letting this session stand will damage their immersion too. It may also damage their ability to trust the cause-and-effect relationship of things within the world, if out-of-game circumstances are allowed to eclipse in-world causes of events in determining what happens.
- Retconning is damaging to investment in the integrity of the story. If you retcon now, what's to say you won't retcon again later? You open the door to further retcons for more frivolous reasons, both in your mind and for your players. If you're going to retcon, you need a solid rationale that explains why this time it's justified, but not next time someone is slightly unhappy with how a session advances the action.
Those all, except for (5), overwhelmingly shout "retcon!" Since I believe (5) can be mitigated with a solid rationale, this interpretation of the details of your question heavily tips the balance toward retconning the session.
Rationale
- The session's events were overwhelmingly driven by out-of-game circumstances, that—if you'd known about them—would have justified not playing in the first place.
In-world causes of events were drowned out almost entirely by out-of-game causes of events. Effectively, this session wasn't even about the stuff in your game. That's not going to happen very often—possibly never again—and sets a very high bar for ever considering a retcon in the future. That should give you a solid bulwark against the temptation to start on a slippery slope of retconning for lesser reasons.
So, with that rationale to justify this retcon, but not lesser temptations to retcon in the future, retcon the session. Wind back the clock, cut out the piece of timeline irreparably damaged by an invasion of causality from a foreign reality, and settle back into the true-to-itself reality that the game had already established before this unfortunate series of events.
Not your fault. It sounds like the rogue's player doesn't really get that it is a game and/or that he has not really grasped that he shouldn't act like a child anymore. He clearly wants to control, to pause the narrative to argue and complain to his own character's advantage. The word that springs to mind is "petulant".
That doesn't really help your group except that you personally should not feel bad, it is everybody's responsibility to behave in a way that supports a fun game and narrative and it doesn't look like that player is keeping up their end of the bargain.
He is not understanding the difference between the players and their characters, the difference between players talking together (telling the story) and characters talking (part of the story).
I would suggest that the point at which you lost a lot of your, errr, authority over the situation was the point at which you backtracked and allowed the rogue's actions to effect the past:
And then it all broke down. The player who plays the rogue wants to stop the monk from touching the rings. I make them do a dex throw and the rogue won. But I had already said the rings disappeared, so in order to keep the narrative going and not allow them to meta-game with the knowledge, I ruled that the rogue was able to stop the monk from taking the ring, but he touched it with a finger and the other two disappeared.
You have already identified this as the point at which "it all broke down". The monk had already succeeded and "The other players did not react", so here you succumbed and let him in.
The one thing I (all of us by agreement actually) am quite strict about is once something has happened it has happened. If it is unfair, sometimes that's life, sometimes it is "repaired" by other things happening... but we never go back once is has happened and we have moved on, even when it is a clear mistake. We write it into the story and move on, and we all have an equal responsibility to accept it and gloss over/ignore any issues and not worry too much about it. If we haven't moved on yet then there is some flexibility, but in your case you waited for a response and then the other rings disappeared, you had moved on and he wanted to change the past because he was to scared to make the first move and then lost out.
They trust me, and each other, enough to not do anything deliberately unfair that is not an expected part of their characters or the set up of the game, and they respond respond to in-character things in-character, and don't take things too personally. They also trust me to be very fair over the whole game in terms of opportunity and to listen at an appropriate time if someone is not enjoying things and try to make it enjoyable again, which is, after all, the point. Even the rules aren't that important, apart from to allow players to have realistic expectations regarding their character's actions.
Setting this situation up takes work by all, not just you. Looks like you have already spoken with him about it and have come to an impasse. The bottom line is this:
"He starts making threats, saying he cant play with us if we can't play like he wants."
If the rest of you don't want to play like he wants, which sounds like a un-attractive way to me, take him up on the offer...
By the way this is a very typical response (seen it before, done it myself) for someone who is taking it all too seriously and can't deal with the feelings and consequences of their actions when it goes wrong. Again it is not your fault. When my children do it, it's called a tantrum and is all very excusable and understandable (if inconvenient and sometimes upsetting) as they aren't mature enough to deal with what they are feeling. It's made better not by giving into their out of control emotions (that just leads to more of the same, through positive reinforcement, which is not good for their emotional development), but instead by making them feel safe and allowed to be upset and have the feelings, but standing firm in the face of them. it means they develop some control and are better able to make decisions about their behaviour. It's a different story and expectation when a twenty-something adult behaves this way and they are often not open to an emotional intelligence based discussion, nor is your relationship with them often one that makes it appropriate to counsel them.
Sorry about the long winded answer. As you may read into what I have written I've encountered this and thought about this quite a lot and have a precarious balance between compassion and lack of patience for adults who don't have the self-awareness to do anything about behaving this way. And I'm not innocent of it myself, though hopefully I left it behind in my early twenties.
Best Answer
It sounds like you've done a great job handling this thus far. You have talked to the players individually and in a group setting, collaboratively created a set of play guidelines, and made sure that expectations are clear. Good job! While these strategies tend to catch about 90% of interpersonal issues, it's clear that they aren't working in this case. I have a theory about why that may be. It's something that comes up fairly frequently with new players.
RPG Confusion, aka "Is This a Video Game?"
My suspicion is that your player is unaware of the differences between a collaborative storytelling game like 5e and an RPG video game (Assasin's Creed, Grand Theft Auto, etc.). In a video game, the creators have made the world and handed it to the players. They typically no longer have any direct control once the players enter the scene. They have pre-defined the type of interactions that are permitted and placed bounds as they wish. If the game makers allow you to kill NPCs through a variety of gory means, then that is clearly meant to be part of the game and no one will get upset with a player for playing that way. If the game allows you to sexually assault characters, steal from them, etc., then those things are a valid form of play, and everyone can expect that players are consenting to be exposed to that sort of content.
Story-telling games are great because they don't have the restrictions that video games have. You can, quite literally, "do anything you want." However, that freedom requires boundaries that the players have to set to make sure that everyone is having a good time. You're obviously familiar with this concept, but I think the issue with your player is that he doesn't comprehend the difference. He is used to being able to do whatever he wants as long as the game physically allows it.
How to Talk About The Issue
My recommendation is to have another 1-1 talk with him and cover some of the following points openly and honestly:
The Minecraft Example
I teach at a technology summer camp, and I often play a simplified version of 5E with my overnight campers (age 10-17). With the younger kids especially, they can have trouble keeping in mind appropriate behavior and understanding co-op games, just like your player. I talk about Minecraft to get them to start thinking about how to help other players have fun. You're welcome to use this directly (with maybe more adult language), port it into some other game, or ignore it.
Nearly everyone has played at least a little bit of Minecraft. It's a really great game. It's most fun when you can play with other people and build together or compete against each other. But playing together can require a lot of trust too. It opens up your world, a place that you've spent hours building and making just so, to people who could come in and destroy it.
We're doing just that. When we play a game like Dungeons and Dragons we are all creating a world together. Everyone contributes and has opinions about what the world is and what it should be. In Minecraft, when we play together, we establish ground rules to prevent anyone from destroying the things that someone else has built (like no TNT) or to set when destruction will be allowed (maybe you can kill someone if they agree to it). When we play this game, we do the same thing. When you hurt someone else's character without permission from them, when you act in ways that the group has agreed are not allowed, or when you ignore what other players want, you are no longer working as a team. Instead, you are destroying parts of the world that those players have built. And that makes the game less fun for everyone, even you.
His Response and Some Further Thoughts
I'm not sure how he will respond to your open discussion of the issue. While we hope that all adults know how to cooperate and how to take constructive feedback, it's not always universally true. There's a possibility that he might rage quit. There's a possibility that he might think about your words and make real change. Who knows. But if he gets angry when you tell him the truth, then you really didn't want him in the group.
In the best case scenario, he thinks about what you say, realizes that you're right, and changes his behavior. You will likely still have to remind him periodically or cut him off if he crosses a line, but that's okay. If he's trying, then you can work with him.
In future situations of this sort, it may be useful to consider not letting new players play characters who are chaotic or evil. I find that it just never seems to go well for their first game. I'm sure that some GMs don't have an issue with it, but I personally do so I just have that policy. As a note, I also never let a player play as a character that is inherently cruel. That's just not a character trait that I'm interested in exploring.
As you guide players through character creation, feel free to limit their ideas in these or other ways. In my experience, doing so will actually help push them to be even more creative and craft more interesting characters that are not simply stereotypes.
Good luck! I hope that everything works out!