Crafting, teamwork, retcons, and the DM's role.

[Talakeal]

Ok, so in my campaign I give a certain amount of downtime for crafting after every adventure.

Everyone in the group is a crafter of some sort, and they pool their resources and frequently craft items for one another.

In last weeks session one of the players was sick and I let the other players control his character. During the downtime at the end of the session one of players asked if the sick player's character could craft a relatively inexpensive item for them, and I said sure.

This week the player found out about it and said that they had no right to have his character craft something without his permission. He is demanding that I retcon it.

I then asked him what he even wanted to craft. and he said that he wanted to start on a grand project to improve one of his own items instead. Now, my system uses logorythmic costs, so, in short, it is going to take him ten sessions worth of downtime to get the same bonus for his own item the same bonus that he gave the other character's gear in one session.

The other player is now saying that if he does this he is no longer going to be a team player, and from this point on 100% of his own crafting will go to improving his own gear as he feels that he is being taken advantage of. Now, while I agree spending ten sessions to give yourself the same bonus you could give another player in one session is being a terrible team-player, this reaction is even worse, and is going to put a huge crack in the party in terms of both efficiency and goodwill.

I am also not sure I like the precedent of demanding the DM to retcon actions your character took while you were absent, especially over something so minor and petty.

So, what do you guys think I should do as the DM?

[Fiery Diamond]

Maybe try something a little less extreme than logorhythmic scaling? Maybe I'm weird, but in my opinion nothing short of "this is a campaign-long objective (or half-campaign objective) should ever take 10 sessions worth to do unless it's the actual adventure itself.

[Talakeal]

Ok, so I just got a message from the player in question. He told me that he is doing it in principle to spite the rest of the group, myself included, because we "Treated him like a slave and literally stole his resources without having the decency to ask him."

So I guess this is a much bigger issue than I thought.

Maybe try something a little less extreme than logorhythmic scaling? Maybe I'm weird, but in my opinion nothing short of "this is a campaign-long objective (or half-campaign objective) should ever take 10 sessions worth to do unless it's the actual adventure itself.

While the exact numbers might need some tweaking, it appears to be working as intended. The idea is to reward balancing out resource distribution over hyper-specialization.

[zlefin]

retcon it away. and if someone misses a session, just send them a message that they can decide how to spend their crafting time and just have it ready by the session after.


tell the other player that it's a matter of rights; it was improper of everyone to ghost a character and spend their limited/valuable resources (Crafting time/money; ghosting them wiht no permanent cost/opportunity cost for the adventure itself is probably fine), so that has to be retconned away.
also, it's selfish and dumb of them to now work only on their own items in response. it would be reasonable to refuse to make items for the character who's spending all their time on their big project; but that's no reason to refuse to help out with the rest of the party who have not done so (assuming they haven't done so and there aren't any other problems with the balance of work done between them)

[JoeJ]

Unless you have some existing agreement about what happens when a player misses*, you should retcon and the let the player control their character.

And then you should, as a group, come to some sort of agreement about what happens the next time one of the players can't be there.


(edit: *and if you do have an existing agreement about this, remind everybody involved what that agreement is.)

[DeTess]

Ok, so I just got a message from the player in question. He told me that he is doing it in principle to spite the rest of the group, myself included, because we "Treated him like a slave and literally stole his resources without having the decency to ask him."

So I guess this is a much bigger issue than I thought.

I doubt you'd get this response form a single isolated incident, so it sounds like you might need to have a chat with he entire group to air out whatever frustrations triggered this. I agree that having the other players spend someone's limited and apparently important resources like that without asking is wrong and should be retconned, as something like this could have just been asked for between sessions over whatever medium of communication you use.

[NecessaryWeevil]

The present players and the DM assumed the absent player would not have a problem with the crafting. It turns out the assumption was wrong. Now everybody knows better and, in this group, PCs of absent characters now simply vanish until the player returns. No ill will was intended, it was all a misunderstanding, the crafting is retconned. Can we please shake and make up and return to having fun? That's how I would try to sell it.

Both players are overreacting.

[Talakeal]

I doubt you'd get this response form a single isolated incident, so it sounds like you might need to have a chat with he entire group to air out whatever frustrations triggered this. I agree that having the other players spend someone's limited and apparently important resources like that without asking is wrong and should be retconned, as something like this could have just been asked for between sessions over whatever medium of communication you use.

This is the first time this has happened.

One sessions worth of crafting time is hardly a valuable resource at all; they are mad over the principle rather than the actual cost.

The present players and the DM assumed the absent player would not have a problem with the crafting. It turns out the assumption was wrong. Now everybody knows better and, in this group, PCs of absent characters now simply vanish until the player returns. No ill will was intended, it was all a misunderstanding, the crafting is retconned. Can we please shake and make up and return to having fun? That's how I would try to sell it.

Both players are overreacting.

I agree both players are overreacting.


Although I proposed the vanish solution, but said that absent characters would not get a share of treasure as the result, which caused the players to both unite and turn their anger on me and said that I was just being "pissy," which might not be too far of the mark; at that point I felt like a parent of small children that don't know how to share who just takes their toys away rather than watch them squabble over them.

[Quellian-dyrae]

My usual rule of thumb is that when I'm NPCing a player, I won't spend limited resources for them - even if I know it would be a good idea strategically. Now, my games are mainly PbP M&M games, while my understanding is that this is a real-time D&D or PF game, so the situation will be somewhat different - when I'm NPCing a PC it's for a turn or two when I need to move things along and they haven't posted, not for an entire session when they can't make it. So it does make sense in that situation to be willing to use some limited resources on their behalf, such as spell slots. But non-renewable resources, such as perishable items, downtime, gold and XP if those are involved, and so on, it's probably a good idea for the DM not to spend on a player's behalf without prior permission.

That being said, it's entirely reasonable given their past activities for you to have assumed the player in question would have been cool with it. Saying the party was treating him like a slave and doing something else to spite them is an overreaction. Likewise, it'd be an overreaction for the other player to no longer assist the rest of the team with crafting where it's otherwise reasonable to do so. I mean, I assume this isn't the first time someone's asked for help with some crafting and the other player said they have something they're already working on but maybe next time, or some such.

My suggestion would be to apologize for the incorrect assumption, retcon the crafting, and allow the player to now spend the downtime resources as normal - including allowing the other player and the rest of the group to make any requests and suggestions they might have as normal. That should hopefully satisfy the first player that he's in control of his resources, and the second that the norms for teamwork have not been changed.

It's probably also worth talking with the group to establish some guidelines going forward for what risks are fair to take and resources fair to spend in situations where the DM or group are controlling an absent player's PC.

EDIT: And that was all well and thoroughly ninja'd.

[Quertus]

Ok, so I just got a message from the player in question. He told me that he is doing it in principle to spite the rest of the group, myself included, because we "Treated him like a slave and literally stole his resources without having the decency to ask him."

So I guess this is a much bigger issue than I thought.

It is, but it's also a different issue.

It's about assumptions.

The absent player assumed he could just show up next session, and tell you what he did during downtime.

The rest of the party just assumed that they could control his character.

You all assumed. Bad y'all.

The absent player was the most correct. That is, what his character would choose to do a) is his to choose, and b) might be affected by the events of the session, and so c) cannot be chosen beforehand, or d) by the other players.

The player gets to do exactly one thing: make decisions for their character. Don't take that away.

Retcon. Explain to your group - and yourself - why this makes sense. Have more formal rules covering this scenario moving forward, so that no one has to assume.

[Talakeal]

Man, now the two players are going back and forth seeing who can overreact the most and I am having to listen to their increasingly over the top revenge fantasies, and if I try and explain that there will be consequences for abandoning the party I become the bad guy. Ugh. FML.


Ok, so let's take this back a bit.

In the past if a player cancels at the last minute I have generally been in groups where we let one of the other players control them or the DM runs them as an NPC.

To do otherwise creates issues with both game balance and plot.

I don't want to cancel the game for a single absent player.

Likewise if the PC just disappears into a plot hole it creates narrative issues, but also balance issues. I need to rebalance the whole adventure on the fly, and if I don't I am risking a TPK.

Furthermore; there is the issue of loot / XP. I like to give them to absent players because otherwise it creates imbalance issues, and apparently I am being "pissy" if I don't give them to absent players.

At this point it seems I am between a rock and a hard place.

[zlefin]

Man, now the two players are going back and forth seeing who can overreact the most and I am having to listen to their increasingly over the top revenge fantasies, and if I try and explain that there will be consequences for abandoning the party I become the bad guy. Ugh. FML.


Ok, so let's take this back a bit.

In the past if a player cancels at the last minute I have generally been in groups where we let one of the other players control them or the DM runs them as an NPC.

To do otherwise creates issues with both game balance and plot.

I don't want to cancel the game for a single absent player.

Likewise if the PC just disappears into a plot hole it creates narrative issues, but also balance issues. I need to rebalance the whole adventure on the fly, and if I don't I am risking a TPK.

Furthermore; there is the issue of loot / XP. I like to give them to absent players because otherwise it creates imbalance issues, and apparently I am being "pissy" if I don't give them to absent players.

At this point it seems I am between a rock and a hard place.

why are they going back and forth? (or have you not decided yet about whether to retcon or not?)
an enforced "calm down until we can talk this over" is justified.

[The Glyphstone]

Why are you even surprised at this sort of thing anymore, Talakeal? This isn't unusual for your players, it's 100% in line with everything we've come to expect out of them and your Bizarro Gaming Universe in general.

[Talakeal]

why are they going back and forth? (or have you not decided yet about whether to retcon or not?)
an enforced "calm down until we can talk this over" is justified.

I said he could make the choice, either we played it as was or we retconned his character from the scenario but would then not get a share of the treasure. Which resulted in a bunch of threats, bile, and name calling directed towards both me and the other player instead of a decision.

[Talakeal]

Why are you even surprised at this sort of thing anymore, Talakeal? This isn't unusual for your players, it's 100% in line with everything we've come to expect out of them and your Bizarro Gaming Universe in general.

I don't know. I honestly thought we were getting better. I had a new group and about six months of good gaming, and now rapid backsliding.

Honestly at this point it seems like my players have spent the last month in a competition with one another to see who can overreact the most over every minor perceived slight.


This isn't even the worst drama this week; but the other one is primarily not game related so I am not going to give any details; but let's just say it ended up pretty damned extreme.

[Quertus]

Man, now the two players are going back and forth seeing who can overreact the most and I am having to listen to their increasingly over the top revenge fantasies, and if I try and explain that there will be consequences for abandoning the party I become the bad guy. Ugh. FML.


Ok, so let's take this back a bit.

In the past if a player cancels at the last minute I have generally been in groups where we let one of the other players control them or the DM runs them as an NPC.

To do otherwise creates issues with both game balance and plot.

I don't want to cancel the game for a single absent player.

Likewise if the PC just disappears into a plot hole it creates narrative issues, but also balance issues. I need to rebalance the whole adventure on the fly, and if I don't I am risking a TPK.

Furthermore; there is the issue of loot / XP. I like to give them to absent players because otherwise it creates imbalance issues, and apparently I am being "pissy" if I don't give them to absent players.

At this point it seems I am between a rock and a hard place.

Ah, thanks! I was trying to remember "FML" for about a week (darn senility).

Anyway...

There is no good answer. There is only the answer that works for your group.

I once wrote out the complex decision algorithm to use for my character should I be absent, and the table of situational statistics that represented my character. The GM took one look at that, and cancelled any session I could not attend. Mission successful.

If you didn't care about "balance" and "challenge" so much, you wouldn't have to rebalance the encounters.

No, seriously.

In a group of ~14 players, we usually cancelled (read: played something else) if even 2 players could not attend. But, one night, only 3 players made it (because of the blizzard). Those of us who were there roleplayed our characters on watch, chatting.

I'm a war gamer. I get "challenge" and "balance". I really do. But an RPG is a really strange place for such concepts.

Anyway, smack your players upside the head, grab them by their ears, sit them down, and tell them to either act like adults, or you'll treat them like children. Continue the conversation according to their response.

Know your group. Find out which imperfect solution works for your group.

Obviously, personally, I think that, in this scenario, "tell me what happened, and I'll tell you what I do during downtime" is the winner.

But what happens to PCs of absent players during the game proper? That's clearly something y'all have to decide for yourselves.

[zlefin]

I said he could make the choice, either we played it as was or we retconned his character from the scenario but would then not get a share of the treasure. Which resulted in a bunch of threats, bile, and name calling directed towards both me and the other player instead of a decision.

did the player want to be retconned from the scenario entirelyy?
or did he just want the crafting part retconned?

if the latter, he'd be justifiably annoyed at the choices you offered.

[Quertus]

I said he could make the choice, either we played it as was or we retconned his character from the scenario but would then not get a share of the treasure. Which resulted in a bunch of threats, bile, and name calling directed towards both me and the other player instead of a decision.

That's... Just... Wtf material. Isn't it? How does this answer not make you as juvenile as your players? Or am I misunderstanding something here?

Do you bring the Bizarro World with you? Do you actively cause your problems? Because that's what I just read.

Why is "you get the treasure, and you choose how your character spends his downtime" not a valid solution?

EDIT: what he said ^

[The Glyphstone]

I don't know. I honestly thought we were getting better. I had a new group and about six months of good gaming, and now rapid backsliding.

Honestly at this point it seems like my players have spent the last month in a competition with one another to see who can overreact the most over every minor perceived slight.


This isn't even the worst drama this week; but the other one is primarily not game related so I am not going to give any details; but let's just say it ended up pretty damned extreme.

I suggest checking your local Yellow Pages under 'Wizard', or at least 'Witch Doctor'. Get a thorough examination for any lingering curses in case you accidentally damaged a mummy sarcophagus or defiled an ancient Native American burial ground at some point in your life. At this point it seems the most likely explanation for why every single group you've ever played in or run a game for goes balls-up insane after a certain point.

[Talakeal]

did the player want to be retconned from the scenario entirelyy?
or did he just want the crafting part retconned?

if the latter, he'd be justifiably annoyed at the choices you offered.

He was pissed that someone else played his character at all, the crafting was the straw that broke the camel's back.

I told him he could retcon it entirely or just roll with it, but I was not going to let him pick and choose what was retconned and what wasn't; although I probably would have even done that if it had been phrased nicely rather than couched in a bunch of hyperbole and threats.

That's... Just... Wtf material. Isn't it? How does this answer not make you at juvenile as your players?

It was a bit exasperated, but no, nowhere near as juvenile as my players.

Saying "you can either have your character participate in the scenario and be played by someone else, good or bad (within reason) and get an equal share or loot, or have your character not participate and not get a share of the loot," is a bit of an ultimatum, but (imo) not anywhere on the same league as "If you don't craft this one item for me I will NEVER craft again," or "If you don't craft I will never help the party again, up to and including running away with the loot rather than healing them if they get injured,".

Likewise, having another character craft a single item for another, which they do every single session, is not nearly the same as saying that he was "literally robbed and enslaved by my fellow players".

[B1okHead]

I'd kick either/both of the players from my group. Worst case scenario I'd cancel the game. No gaming is better than bad gaming imo

[Quertus]

He was pissed that someone else played his character at all, the crafting was the straw that broke the camel's back.

I told him he could retcon it entirely or just roll with it, but I was not going to let him pick and choose what was retconned and what wasn't; although I probably would have even done that if it had been phrased nicely rather than couched in a bunch of hyperbole and threats.



It was a bit exasperated, but no, nowhere near as juvenile as my players.

Saying "you can either have your character participate in the scenario and be played by someone else, good or bad (within reason) and get an equal share or loot, or have your character not participate and not get a share of the loot," is a bit of an ultimatum, but (imo) not anywhere on the same league as "If you don't craft this one item for me I will NEVER craft again," or "If you don't craft I will never help the party again, up to and including running away with the loot rather than healing them if they get injured,".

Likewise, having another character craft a single item for another, which they do every single session, is not nearly the same as saying that he was "literally robbed and enslaved by my fellow players".

Let me put this differently.

Player: I missed the session, and so lost the joy of getting to play the character and experience the world while they played without me. But at least I get to handle the downtime. Wait, what? They took that from me, too? Why would they do that? There is absolutely no reason for them take that choice from me. I oppose this on principle.

GM: well, someone had to play your character while you weren't there, so I let them also play the part that you could have chosen now, too. If you want me to retcon them playing the downtime, I'm going to retcon your character into not being there at all.

...

My question remains, why it's it alien to your mindset to just retcon the downtime, but not the adventure? Why not give them the choices that they could have made once you told them how the session went?

Also, in that group? I'd half expect PCs of absent players to give all their worldly possessions to their fellow PCs before committing suicide.

Yes, the GM has a responsibility to the absent players.

(EDIT: really, so do the other players, but...)

EDIT: the nuances of every decision you make, how and why you make them, affects the group. I ask you again to ponder to what extent you bring Bizarro World with you.

[Talakeal]

Let me put this differently.

Player: I missed the session, and so lost the joy of getting to play the character and experience the world while they played without me. But at least I get to handle the downtime. Wait, what? They took that from me, too? Why would they do that? There is absolutely no reason for them take that choice from me. I oppose this on principle.

GM: well, someone had to play your character while you weren'tAlso, in that group? I'd half expect PCs of absent players to give all their worldly possessions to their fellow PCs before committing suicide.
there, so I let them also play the part that you could have chosen now, too. If you want me to retcon them playing the downtime, I'm going to retcon your character into not being there at all.

...

My question remains, why it's it alien to your mindset to just retcon the downtime, but not the adventure? Why not give them the choices that they could have made once you told them how the session went?


Yes, the GM has a responsibility to the absent players.

(EDIT: really, so do the other players, but...)

Because you are phrasing it as a reasonable request, not a hyperbolic statement full of rage and threats.

The thing is, it isn't about enjoying downtime or even RPing his character / power gaming. He is taking a suboptimal and antisocial action purely to spite the other player for daring to play his character while he was gone.

And keep in mind, it is, as you pointed out, now a matter of principal. The other player is now forever screwed as he will NEVER get his item crafted, as the player is punishing him for daring to "rob and enslave his character". And when I pointed out that he didn't have anything better to craft at the time and it was the optimal decision, he doubled down on the matter and decided to dedicate himself to a grand product which will take ~10 sessions for a negligible benefit, thus harming the entire rest of the party.

[doctor doughnut]

I think this is all the DMs fault. Right from the second the DM decided what the players character did.

The best, and really only, answer is: the player character does whatever they player wants. So, as DM, you really should have just said ''no". Or maybe you could have contacted sick player and asked them?

Some one misses a game as they are sick...a good reason....and when they come back they just the supprise of ''oh, hehe, he is what we did behind your back with your character". Well, how would you expect them to feel?

This is why ''no'' is the best and only answer.

[Talakeal]

Well, how would you expect them to feel?

This is why ''no'' is the best and only answer.

I would expect them to be fine with it. I have gamed with dozens of groups over dozens of years, and I have never seen someone react like this to what is otherwise a very common thing. I have missed sessions and had someone else play my character until I got back without issue, and I have played other people's characters while they were gone without issue.

Players miss sessions, it happens, its just not feasible to cancel the game every time a single player can't make it, especially if you are in a large group where people have RL commitments.

So let me ask you, how would a theoretical "perfect DM" handle it? Just cancel every session if a single player can't make it? Have the character's of absent players instantly disappear into hammer space plot or game balance be damned?

[doctor doughnut]

So let me ask you, how would a theoretical "perfect DM" handle it? Just cancel every session if a single player can't make it? Have the character's of absent players instantly disappear into hammer space plot or game balance be damned?

Yes? This is the way I have always done it, and the way I have seen most other games do it. "Real Life Writes the Plot" and all.

If your really obssessed with some sort of perfect fictional reality, you can just say the character was lost or trapped or stuck or such.

And if your game is so badly balanced they it can't handel a character being gone...well, you'd need to work on your balance.

Fun Twist: I've done this a couple time: when a player misses a game....they get replaced by a doppeganger (or demon or whatever). The poor players, baddly meta gaming of course, just ''think" the DM is playing the "real" character.....and wow, do they get a huge shock when they find out they have been fooled. It's great fun.

[Talakeal]

If your really obssessed with some sort of perfect fictional reality, you can just say the character was lost or trapped or stuck or such.

Yeah, as I said, dozens of groups over several decades, never seen it done that way and never (before now) seen anyone object to it.

And if your game is so badly balanced they it can't handle a character being gone...well, you'd need to work on your balance.

That is literally the exact opposite of what the word "balance" means.

[NichG]

Your job is not to ensure that the party makes optimal decisions, has a high level of teamwork, or to punish what you see as irrational behavior. Your job is to adjudicate outcomes fairly and mediate between players. When you made an ultimatum to the player to allow the crafting or have their treasure docked, you were basically saying to them 'I think your concerns are invalid and I will not hear them or take them into account, I'm just going to use my position of power in this situation to make you back down'. That doesn't answer the player's concerns, and furthermore it makes it seem more likely that those concerns will never be satisfactorily respected within the group. So what rational action do they have left in such a situation?

If you're playing an iterative cooperation game where someone defecting can extract value from you without giving you a chance of getting what you want in return, it's a nearly optimal strategy to declare the ultimatum 'I will work with you, but if you betray me more than X times I will always betray you from then on'. What the player is doing is actually an almost optimal rational response in the situation where there's something they care about which has basically been refused to be acknowledged. They're punishing the group because it's the only power you've left them to resolve this dispute after, from their point of view, dismissing their concerns as petty.

If you want to mediate this, you have to take a position where you aren't judging the validity of their concerns, but rather trying to find a compromise that addresses the concerns of both sides. Once you've taken a side, it's only going to escalate.

You could for example say 'this time, you get your item for free, you get your downtime back, and in the future any resource expenditure or character decision with lasting consequence has to be okayed by the absent player in advance; that's how I'll run it from now on, and that's where the rules part of this discussion ends. If there's still a problem between you two, we need to work it out as a group of players rather than as you asking the DM for a ruling'

[Quellian-dyrae]

Okay...here's what I'd suggest at this stage.

First, you have to nip this whole matter of principle idea in the bud. Admit that mistakes were made. You assumed Player A would be cool with others controlling his character for a session and doing the crafting. Player B assumed it was a fair question to ask if Player A's character would be doing the crafting. Player A took reasonable offense to a perceived violation of agency. All of these assumptions were reasonable, and all of them were wrong. It happens. What is important now is getting the game back on track so that everyone can have fun.

As best I can tell, the session went through with no apparent downside to Player A's character aside from the expended downtime resources. Refund those, and remove the item that was crafted with them. Allow Player A to use them on something else if he wants to. Allow the rest of the team, including Player B, to make their usual input and requests as they normally would. This should still work to establish that nobody was trying to intentionally take advantage of Player A, and that normal teamwork is still in effect.

As for playing his character in the session, it happened, it was an innocent error. If he really wishes to retcon his character out of the prior session entirely, for good and ill, let him do so. Or if he's satisfied with the fact that the session resulted in more benefit than loss to his character, let it stand. The choice of whether or not to retcon the session should be irrelevant to the choice of what to do with his downtime, since they're two separate circumstances.

A discussion with the entire group should take place to establish reasonable guidelines for how to handle absent players in the future. Emphasize that it is much easier for you as DM if they can be NPC'd to some degree, but if anyone really has problems with it hash out alternatives. I agree that someone else playing absent PCs is perfectly acceptable and often a better solution than just having them vanish (and a way better solution than cancelling the session for everyone), but everyone does need to be on board with it, and there does need to be some ground rules. Things to consider include, but are not necessarily limited to:
-Is everyone okay with the DM or a different player playing their character? And who would they prefer to play them?
-What resources are allowed to be used when someone else is controlling the character?
-How much risk is the character allowed to be made to accept on behalf of the party?
-Does the character get role-played, or does it just kinda passively follow along and contribute to mechanical challenges? In the former case, you may also want to establish guidelines for just how much creative control the controller has, to make sure nobody forces a PC to act in a way its player would regard as out-of-character.
-If something does happen during a session that the player is fundamentally opposed to, what recourse is available?

I...think that should more-or-less address everyone's fundamental concerns in a reasonable and neutral manner so the game can again start moving in a positive direction. If your players still insist on threats, ultimatums, and conflict...well that suggests underlying problems that I know I'm not equipped to offer advice on, beyond "try to talk it out".

[Talakeal]

Your job is not to ensure that the party makes optimal decisions, has a high level of teamwork, or to punish what you see as irrational behavior. Your job is to adjudicate outcomes fairly and mediate between players. When you made an ultimatum to the player to allow the crafting or have their treasure docked, you were basically saying to them 'I think your concerns are invalid and I will not hear them or take them into account, I'm just going to use my position of power in this situation to make you back down'. That doesn't answer the player's concerns, and furthermore it makes it seem more likely that those concerns will never be satisfactorily respected within the group. So what rational action do they have left in such a situation?

If you're playing an iterative cooperation game where someone defecting can extract value from you without giving you a chance of getting what you want in return, it's a nearly optimal strategy to declare the ultimatum 'I will work with you, but if you betray me more than X times I will always betray you from then on'. What the player is doing is actually an almost optimal rational response in the situation where there's something they care about which has basically been refused to be acknowledged. They're punishing the group because it's the only power you've left them to resolve this dispute after, from their point of view, dismissing their concerns as petty.

If you want to mediate this, you have to take a position where you aren't judging the validity of their concerns, but rather trying to find a compromise that addresses the concerns of both sides. Once you've taken a side, it's only going to escalate.

Keep in mind, the "ultimatum" wasn't until after they had already been screaming at and threatening each other for quite some time. He was LONG past the point of punishing the rest of the group before I said a word.

It was less of an ultimatum and more of an exasperated "cut the baby in half" solution to them expecting me to side with one of them over the other when they were both being completely overblown and irrational.

Okay...here's what I'd suggest at this stage.

First, you have to nip this whole matter of principle idea in the bud. Admit that mistakes were made. You assumed Player A would be cool with others controlling his character for a session and doing the crafting. Player B assumed it was a fair question to ask if Player A's character would be doing the crafting. Player A took reasonable offense to a perceived violation of agency. All of these assumptions were reasonable, and all of them were wrong. It happens. What is important now is getting the game back on track so that everyone can have fun.

As best I can tell, the session went through with no apparent downside to Player A's character aside from the expended downtime resources. Refund those, and remove the item that was crafted with them. Allow Player A to use them on something else if he wants to. Allow the rest of the team, including Player B, to make their usual input and requests as they normally would. This should still work to establish that nobody was trying to intentionally take advantage of Player A, and that normal teamwork is still in effect.

As for playing his character in the session, it happened, it was an innocent error. If he really wishes to retcon his character out of the prior session entirely, for good and ill, let him do so. Or if he's satisfied with the fact that the session resulted in more benefit than loss to his character, let it stand. The choice of whether or not to retcon the session should be irrelevant to the choice of what to do with his downtime, since they're two separate circumstances.

A discussion with the entire group should take place to establish reasonable guidelines for how to handle absent players in the future. Emphasize that it is much easier for you as DM if they can be NPC'd to some degree, but if anyone really has problems with it hash out alternatives. I agree that someone else playing absent PCs is perfectly acceptable and often a better solution than just having them vanish (and a way better solution than cancelling the session for everyone), but everyone does need to be on board with it, and there does need to be some ground rules. Things to consider include, but are not necessarily limited to:
-Is everyone okay with the DM or a different player playing their character? And who would they prefer to play them?
-What resources are allowed to be used when someone else is controlling the character?
-How much risk is the character allowed to be made to accept on behalf of the party?
-Does the character get role-played, or does it just kinda passively follow along and contribute to mechanical challenges? In the former case, you may also want to establish guidelines for just how much creative control the controller has, to make sure nobody forces a PC to act in a way its player would regard as out-of-character.
-If something does happen during a session that the player is fundamentally opposed to, what recourse is available?

I...think that should more-or-less address everyone's fundamental concerns in a reasonable and neutral manner so the game can again start moving in a positive direction. If your players still insist on threats, ultimatums, and conflict...well that suggests underlying problems that I know I'm not equipped to offer advice on, beyond "try to talk it out".

Well, that would work except that player A will NEVER craft for player B again and will not craft for the rest of the party for the next ~10 sessions.

This is basically giving player A everything they want, and teaching them that threatening the rest of the group and bullying the DM over trivial things is the best way to get ahead in the game, and punishes player B for daring to take an innocuous action that best for the team at the time.