Withholding Quest information as a PC

[Ashizard]

First some backstory

I play a warlock who has been given a second chance by the Great old one (In this case a giant leviathan at the bottom of the ocean) the price is that I have to place a conch shell on the corpses of my slain enemies (In character I don't know what this does, I'm happy not to be dead but not to keen to go shouting about how other peoples deaths benefit me). I spoke with my DM and asked if I could have a conch as my trinket from my background and that i wasn't expecting anything from the DM it was more just a flavor thing, DM was happy I was happy.

Its been a point of interest in the game but nothing sinister....

Anyway! The DM has decided he wants to use this in game and had one of the group find a book that once deciphered showed diagrams of someones soul being removed by a conch shell.
The wizard in question wasn't keen on divulging this information and it caused a bit of upset between some of the players

one of the players concern is that if its a plot hook they should all know what it says especially since he found the book whereas another player thinks that if he understood the book but no one else can, he has sole rights to its information
Personally I think he should have just lied and said he couldn't read the book...

What do you guys thing with regards to this/other similar moments you might have had? how do you weigh up role playing versus possible quest information not being given to all the characters

[CaptainSarathai]

It's a question of meta-knowledge; the player should tell the others what he has found, but it needs to be understood that unless their characters are told this information, they have no idea.
And their characters don't need to know. If that causes problems, then those are issues within the party - maybe the Rogue wants to try stealing the book and having someone else decipher it. As a DM, I don't really encourage the party to work against each other, but that's also why I wouldn't require the Wizard to tell them anything.
Think about it - what might the Lawful Good Paladin say, now that he knows this? Is he going to try and stop the Warlock? What would that do to the Lock's Pact? The two might very well come to blows over this, tear the party apart, or kill one another. It might be better that the other characters don't know - and that might be exactly why the Wizard is lying and saying,
"Nope, honest guys, I can't read it at all"
And the players need to remember that this is all the knowledge of the situation that their characters are gonna get.

[Ashizard]

What's scary is that I didn't mention the chap upset plays a LG paladin who has previously tried to smash my conch... but that's what I'd rather avoid... I quite like my warlock lol

[CaptainSarathai]

See? We Warlocks have to stick together!

[Laserlight]

one of the players concern is that if its a plot hook they should all know what it says

Nonsense. If one player wants to keep a secret, that's his choice. In that situation, I would write down the info and pass it to him privately to avoid any metagaming. If he wants to lie about what it says, and the other players are in a situation where they could reasonably pay attention to his expression, i might make a secret Deception v Insight check, and tell the questioner "He seems nervous / upset / distracted" on a good roll, but I wouldn't tell what's in the book.

[Pex]

Oh how I loathe players who absolutely refuse to tell the party important need to know information their character discovers. They get their jollies and feel superior in Knowing Something the others don't. These players cannot be reasoned with. Ask the DM to arrange for the rest of the party to learn the information so the plot hook can commence normally. Never trust the wizard player on anything ever again because he has proven his lack of trust until and unless he Honest True changes his behavior. It is irrelevant that it's out of character proof because it's an out of character problem. If the DM refuses to arrange the rest of the party learn the information then he is enabling the Jerk player to ruin everything. Then you must decide for yourself if you're having fun playing more than this issue is bothering you. If not, leave.

I know this sounds harsh. I speak from experience. If the DM corrects the issue the Jerk player either shapes up or ships out. Win win. If the DM enables the behavior it never ends well. Ever. Every time.

[Addaran]

Oh how I loathe players who absolutely refuse to tell the party important need to know information their character discovers. They get their jollies and feel superior in Knowing Something the others don't. These players cannot be reasoned with. Ask the DM to arrange for the rest of the party to learn the information so the plot hook can commence normally. Never trust the wizard player on anything ever again because he has proven his lack of trust until and unless he Honest True changes his behavior. It is irrelevant that it's out of character proof because it's an out of character problem. If the DM refuses to arrange the rest of the party learn the information then he is enabling the Jerk player to ruin everything. Then you must decide for yourself if you're having fun playing more than this issue is bothering you. If not, leave.

I know this sounds harsh. I speak from experience. If the DM corrects the issue the Jerk player either shapes up or ships out. Win win. If the DM enables the behavior it never ends well. Ever. Every time.

Nothing in the OP says it's important, needed information. The paladin is scared that it might be a plot hook, but we don't know if it's true.

On the other hand, depending on the players, the information could cause in-party fighting. The paladin could say that the warlock is pure evil since he stole souls (even if he didn't know) and try to kill him. Often pure LG or paladins are as much of a problem if not more for party cohesion then evil characters.

Depending on the DM, if the warlock stops doing it he might lose his powers or be unable to gain more level in the class. Wich could impact the OP's fun.

So IMO, the wizard isn't doing it to feel superior, but for the warlock and the party cohesion.

[Hopeless]

Okay so only the wizard knows and nobody else has read that book?
Unless the paladin has legitimately been able to detect evil he has no reason to destroy that conch shell doesn't he?
Maybe you should ask your dm to make it clear what everyone knows?

As it stands you have no ideas of the relevance of the conch shell only that you are following your own tradition which as far as you know is purely a custom you were trained to follow.

That book unless your wizard comes clean about might be completely rubbish, after all who wrote it and can they confirm the information in it is actually reliable?

I'd say if your character learned about this they might want to find out for sure since you clearly didn't know about it, but the paladin is clearly acting on information his character doesn't know so should know better!

[Contrast]

Oh how I loathe players who absolutely refuse to tell the party important need to know information their character discovers. They get their jollies and feel superior in Knowing Something the others don't. These players cannot be reasoned with. Ask the DM to arrange for the rest of the party to learn the information so the plot hook can commence normally. Never trust the wizard player on anything ever again because he has proven his lack of trust until and unless he Honest True changes his behavior. It is irrelevant that it's out of character proof because it's an out of character problem. If the DM refuses to arrange the rest of the party learn the information then he is enabling the Jerk player to ruin everything. Then you must decide for yourself if you're having fun playing more than this issue is bothering you. If not, leave.

I know this sounds harsh. I speak from experience. If the DM corrects the issue the Jerk player either shapes up or ships out. Win win. If the DM enables the behavior it never ends well. Ever. Every time.

Except...is this important need to know information? Is this even a plot hook or just a case of one of the players actions having consequences?

Presumably the party already knew the Warlock was up to something with the bodies of the slain and conch shells or why did the paladin try to smash his conch shell. They could just ask the warlock why he keeps putting conch shells on the dead. Maybe he has already come up with a lie.

Maybe the reason the wizard isn't saying anything is because he sees the warlock as an asset in fighting the BBEG and worries that if he reveals his knowledge the paladin will insist stopping/hurting their quest to stop the BBEG by stopping the warlock. Maybe he's keeping it to himself until he's had a chance to speak to the warlock pirvately and find out whats up (particularly if the warlock has not presented himself as a bad person).

If the information was 'here is the 3 step plan to defeating the BBEG' and one player is keeping it to himself and then dies without telling anyone I could see your point. But in this case what are the consequences if the wizard doesn't tell anyone and then dies. Nothing - the party just carries on as before the DM introduced the book. Hell, depending on how he died they would even still have the book and could pick the story thread up again at the DMs discretion.

I'm going to take the opposite stance here. I understand you may not be a fan of inter-party conflict (which can be good when done maturely but thats another topic) but having in character motivations which differ from other characters is one of the key parts of roleplaying. One of the players in my group finds it almost impossible to get in character motivations and the like in her head and has a tendency to just share everything with everyone. As a result she tends to get sheparded away from speaking to NPCs because she can't be trusted to guage what we want to be known and what to keep secret. When I've tried to get her involved in schemes which involve different people knowing different things its all fallen apart for this reason.

If your objection is to someone keeping secrets from the party then surely the warlock was at fault from the start for hiding his relation to a soul stealing monster from the deep. I don't think thats the case. Incidentally, if you are going for your warlock being non-evil you should probably be looking for some way out of this bargain though...

[CursedRhubarb]

Sounds like an awkward situation but has potential for great rp moments. The Wizard keeping quiet isn't a big deal as his silence potentially keep the Warlock safe from confrontation.
If the warlock is truly unaware of what actually happens with the shell then even if the Paladin finds out about what's in the book he won't be able to do anything to the Warlock.

Paladin uses Zone of Truth,
Paladin:I know you are stealing souls and damning them to the abyss!
Lock: I've done no such thing. I just put the shell on them and say a prayer for their soul to be safe on it's way.
ZoT detects truth...
Paladin: But...but the book says...
Lock: Could be a fake or be something else. Now I demand repentance for these accusations and hardships from you, on your honor!

Put that pally in his place.

[Demonslayer666]

Sounds like an awkward situation but has potential for great rp moments. The Wizard keeping quiet isn't a big deal as his silence potentially keep the Warlock safe from confrontation.
If the warlock is truly unaware of what actually happens with the shell then even if the Paladin finds out about what's in the book he won't be able to do anything to the Warlock.

Paladin uses Zone of Truth,
Paladin:I know you are stealing souls and damning them to the abyss!
Lock: I've done no such thing. I just put the shell on them and say a prayer for their soul to be safe on it's way.
ZoT detects truth...
Paladin: But...but the book says...
Lock: Could be a fake or be something else. Now I demand repentance for these accusations and hardships from you, on your honor!

Put that pally in his place.

Read all the way through the thread excited to post... only to find my exact thoughts in the last post. Well said.

This information doesn't mean or prove anything. It just sets you in a bad light. That's how you have to play it off if it gets revealed.

Oh, and if your warlock gets sacrificed for the story, remember that he will live in infamy. :smallsmile:

[Pex]

One character's minor quirk got promoted to potential campaign relevance via getting referenced by a third party source. That is important need to know information. You're supposed to be a party working together trying to figure things out. Upon discovering the book, the warlock, the wizard's friend, should have been the absolute first person the wizard talked to about it. The warlock could then develop his character more deeply describing his Patron. The party could then investigate together whether there is a connection or it's just a coincidence. Perhaps DMium would have taken place if the wizard gave the warlock the book. Secret Hidden Writing might have manifested or the warlock got a Vision or Something Happens just for the incidence of him touching the book.

[Segev]

I will chime in here to say that, both as a player and as a DM, it is incredibly frustrating when players won't share plot hooks and information leads with the other PCs in character. I have seen more games grind to a halt because half the PCs had plot-relevant info they were playing close to their chests and thus couldn't put together with the other info the others had and wouldn't take the party to go investigate.

It is my not-so-humble advice that this is a time to metagame hard: FIGURE OUT reasons why the PCs would share this information. Contrive these reasons, if you have to. It will make the game better.

[CaptainSarathai]

I will chime in here to say that, both as a player and as a DM, it is incredibly frustrating when players won't share plot hooks and information leads with the other PCs in character. I have seen more games grind to a halt because half the PCs had plot-relevant info they were playing close to their chests and thus couldn't put together with the other info the others had and wouldn't take the party to go investigate.


Characters playing close to the chest over simple stuff is one thing, but when it's a situation that almost demands inter-party conflict, then I say they are right to keep it quiet.
Everyone here is suggesting that the Paladin know, but that the Warlock find a way to play it off or persuade him to back down - from the sounds of it, that's not happening with this particular Pally's player. The guy already tried to smash the conch based on pure suspicion alone. To have even a shred of proof, he's either going to crush the shell, force the Warlock to break Pact, or just kill the Warlock. Or they're going to have to kill the Paladin.

I agree with the others - RPing a truly Lawful Good character should be reserved for only the very best and most mature players, because they can be extremely disruptive if they just let every little thing turn into a morality crusade. Some people just can't accept that the Party comes first, THEN your bonds and morals. Heck, I was once introduced into a campaign playing a Tiefling, and one player's "character" threatened to kill him because his bond was to destroy all demons and any who consort with them. I stopped, OOC to ask "are you serious" and the guy honestly said "It's what my character would do." He had every intention of just murdering a random Tiefling met on the road. Needless to say, when he needed help, my character let him die, because "that's what my character would have done." Idiot...

[RickAllison]

As a DM who has fallen victim to players withholding plot-important information from other PCs (in a Star Wars campaign, the galaxy was enslaved by an ancient race of constructs because the droid who survived a party catastrophe refused to inform the rest of his companions on the plot hooks they had been following so he could focus on his droid revolution), it can be quite frustrating. On the other hand, this plot twist has rendered the wizard complicit with possibly evil activities and created an awesome intrigue scenario as the four PCs all have different viewpoints on the subject!

My advice: Ask the DM on his opinion (how unhelpful...). The Paladin thinks it might be plot-crucial, the wizard thinks it might not be, and suggest to the DM that if it is plot-critical, he can find another way to give the information to the party. If not, ask the paladin and rogue to pursue it as they will, but that the wizard is not obligated to divulge the info.

[Maxilian]

If the information is needed for the Plot, then the DM will find another way to get this info (or part of it) to the other PCs, if such debate still exist, just talk it out with your DM.

[Segev]

If the information is needed for the Plot, then the DM will find another way to get this info (or part of it) to the other PCs, if such debate still exist, just talk it out with your DM.

Speaking as a DM, it gets increasingly frustrating to try to do this when every time you drop something on the party your best avenues hoard it and thus don't even know others in the party are interested in it. It can get to the point that you have to have an NPC walk up to the party and explain the whole thing in a ham-handed way, because there's no logical way to tell the people who don't yet have it what they need to know.

Worse, I've seen players get annoyed that people were "let in" on their secret information. :smallmad:

So, players, if you are given something by the DM, a little metagaming to just ask him if he intends you to share it with the rest of the party might be wise before you choose to keep it secret.

[Breashios]

Both Segev and Pex have great points based on their experience. Based only on my own experience, however, I have to differ. As a DM (and GM of other systems as well), I have found it to be an enjoyable challenge to deal with exactly these kind of situations - One of which is a favorite fun nostalgic moment for the old timers in my group.

My bottom line: It depends on the DM. What does he want to accomplish? And then, what leads to the most enjoyment. If keeping secrets either makes a player’s day or fits a character’s character, then more power to that. If the DM needs the info to come out he just needs to manufacture another source of the necessary information. It doesn't have to be ham-handed. It can actually be done elegantly with a nod toward another character's unique trait.

In this case the paladin could have a dream (that also tells him to act with compassion or care regarding the warlock). Maybe the paladin is the subject of a geas that requires he redeem the warlock and in fact cannot allow him to die unredeemed. The group could encounter a sage that notices the conch in the warlock’s possession or a ranger who knows something similar to the information in the book (which he learned from an aged shaman years ago) and has heard about this individual placing a shell on dead bodies, catches up to the group and expresses his concern. The information these sources provide might be slightly off what the wizard has read or add more information while leaving some out. If the DM believes the PC is acting out of character, he could discuss that with the wizard aside and help that player find a way to present the necessary information to the group in a manner that would divert conflict.

I’ve experience no problem discussing with my players why their character chose not to share important information and either understanding they did the right thing for them or helping them bring the information to light within character. Nor have I experienced any pattern of this behavior (except by individual characters playing in character).

[Sigreid]

Speaking as a DM, it gets increasingly frustrating to try to do this when every time you drop something on the party your best avenues hoard it and thus don't even know others in the party are interested in it. It can get to the point that you have to have an NPC walk up to the party and explain the whole thing in a ham-handed way, because there's no logical way to tell the people who don't yet have it what they need to know.

Worse, I've seen players get annoyed that people were "let in" on their secret information. :smallmad:

So, players, if you are given something by the DM, a little metagaming to just ask him if he intends you to share it with the rest of the party might be wise before you choose to keep it secret.
I have a different perspective. If someone doesn't share something and the party suffers for it or misses an opportunity, that's on them. They suffer the consequences. To me, hand holding DMing is the same as railroading. Besides, after a few times that it bites them, they may learn to be a bit more forthcoming with people they already trust their lives to.

[SLIMEPRIEST]

It seems pretty obvious that if you tell a player something in secret, that player most likely isn't going to want reveal it to his companions. At least not right away. Why even give the info secretly if the player is going to just repeat it to everyone? Waste of time. Players don't know what info is a 'nessecary' plot hook and what isn't. It's up to the dm to control the flow of info. Always assume secret info will create party conflict. It almost always does. The whole point is to add intrigue to the party sorry. The op's dm created this situation and the players have to solve this problem like any other. Once party members start killing each other it's game over man. Might as well be a tpk.

[Pex]

I have a different perspective. If someone doesn't share something and the party suffers for it or misses an opportunity, that's on them. They suffer the consequences. To me, hand holding DMing is the same as railroading. Besides, after a few times that it bites them, they may learn to be a bit more forthcoming with people they already trust their lives to.

Some players want this to happen and won't change their behavior. They don't care bad consequences will happen because it won't happen to them since they Know The Secret. If other PCs lose items or their lives these players are happy at worst or don't care at best. They are the superior player for learning The Secret and not suffering anything because of it. This is not hyperbole. I've seen it too many times. It gets exacerbated when the DM enables the behavior whether by Honest True innocently not wanting to railroad or more often the case because they lack empathy themselves and will just let PCs screw themselves over because one PC refuses to cooperate. Everyone is out for themselves. PCs won't necessarily attack each other, but they are not a party. They are a group of individuals who just happen to be traveling in the same direction and fighting the same foes with a DM seeing what he can get away with. I had to quit my first 5E game because of this.

[Sigreid]

Some players want this to happen and won't change their behavior. They don't care bad consequences will happen because it won't happen to them since they Know The Secret. If other PCs lose items or their lives these players are happy at worst or don't care at best. They are the superior player for learning The Secret and not suffering anything because of it. This is not hyperbole. I've seen it too many times. It gets exacerbated when the DM enables the behavior whether by Honest True innocently not wanting to railroad or more often the case because they lack empathy themselves and will just let PCs screw themselves over because one PC refuses to cooperate. Everyone is out for themselves. PCs won't necessarily attack each other, but they are not a party. They are a group of individuals who just happen to be traveling in the same direction and fighting the same foes with a DM seeing what he can get away with. I had to quit my first 5E game because of this.
And the players are perfectly within their rights to refuse the company of the character that puts them in unnecessary harm's way without their knowledge and consent. Whatever way they handle it, it's up to the players to work that out.

[Blue Duke]

One character's minor quirk got promoted to potential campaign relevance via getting referenced by a third party source. That is important need to know information. You're supposed to be a party working together trying to figure things out. Upon discovering the book, the warlock, the wizard's friend, should have been the absolute first person the wizard talked to about it. The warlock could then develop his character more deeply describing his Patron. The party could then investigate together whether there is a connection or it's just a coincidence. Perhaps DMium would have taken place if the wizard gave the warlock the book. Secret Hidden Writing might have manifested or the warlock got a Vision or Something Happens just for the incidence of him touching the book.

with an LG paladin in the game...i suspect he's lucky he didn't get shanked for being a warlock in the first place, maybe the wizard should have told the Warlock but whose to say the paladin wouldnt just happen to be nearby to roll a perception check to overhear and cause issues ?'



And the players are perfectly within their rights to refuse the company of the character that puts them in unnecessary harm's way without their knowledge and consent. Whatever way they handle it, it's up to the players to work that out.
How often is that an option ? i get people getting annoyed when i pull my characters because they don't like how the party is acting.....how is any one free to just go 'bye' or 'get out' respectively and not cause massive issues in the group.......is this another one of those fantasy lands populated by tabletop gamers ?

[Pex]

And the players are perfectly within their rights to refuse the company of the character that puts them in unnecessary harm's way without their knowledge and consent. Whatever way they handle it, it's up to the players to work that out.

But then they get chastised by the secretive player for metagaming and the enabling DM for whining.


with an LG paladin in the game...i suspect he's lucky he didn't get shanked for being a warlock in the first place, maybe the wizard should have told the Warlock but whose to say the paladin wouldnt just happen to be nearby to roll a perception check to overhear and cause issues ?'


An Awful Goo aligned Paladin who smites at anything or anyone who even looks at him funny is its own set of problems.

[Sigreid]

with an LG paladin in the game...i suspect he's lucky he didn't get shanked for being a warlock in the first place, maybe the wizard should have told the Warlock but whose to say the paladin wouldnt just happen to be nearby to roll a perception check to overhear and cause issues ?'



How often is that an option ? i get people getting annoyed when i pull my characters because they don't like how the party is acting.....how is any one free to just go 'bye' or 'get out' respectively and not cause massive issues in the group.......is this another one of those fantasy lands populated by tabletop gamers ?

Hopefully it only has to happen once when the party barely survives something and finds out that one of their number did not share vital information.

At this point though, no one has any real reason to believe that the book is anything more than fluff the DM is using to add a little depth to the world.

[Sigreid]

But then they get chastised by the secretive player for metagaming and the enabling DM for whining.


We apparently play with very different groups. Regardless though, I refuse to spoon feed the party information. Among other things finding a way to get information to the party around a secretive PC confirms the value of the information. This is in addition to it being very much a choo-choo train.

[Thrudd]

It depends on the tone of the game, for me. If I'm DMing a straight forward dungeon crawl game, I'm giving information to the whole party and don't facilitate intra-party conflict. I'm not going to keep track of who knows what and who heard what. If someone deciphers a language with their skill or spell, I tell everyone because it is assumed the deciphering character has shared the information.

If I'm running a game where secret histories and uncertain motives play a part in the character's interaction, then I will make sure to segregate knowledge when appropriate and let the players decide what to share or not. For this book situation, I'd write down the important part of what is within and hand that to any player that can read the book. This avoids the situation where the DM tells the wizard player, in front of everyone, what they learn, and now everyone has information their characters aren't supposed to have and need to pretend they don't know.

[Segev]

I have a different perspective. If someone doesn't share something and the party suffers for it or misses an opportunity, that's on them. They suffer the consequences. To me, hand holding DMing is the same as railroading. Besides, after a few times that it bites them, they may learn to be a bit more forthcoming with people they already trust their lives to.

When those consequences are "the party can't do anything because they can't find activities to perform," it becomes a greater problem. Players start to feel, at best, that they're spinning their wheels to no avail. (At worst, they can't even get the wheels spinning.)

"Well that's their fault" is not helpful. Neither is "just give them more to do," because we're back to ham-fistedly saying "and now, because you're destined heroes, the plot drops in your laps." Or to them accomplishing nothing at all. Not even having fun during the session.

It's not "hand-holding" to want the players to have meaningful options in terms of how to address the setting.

[Sigreid]

When those consequences are "the party can't do anything because they can't find activities to perform," it becomes a greater problem. Players start to feel, at best, that they're spinning their wheels to no avail. (At worst, they can't even get the wheels spinning.)

"Well that's their fault" is not helpful. Neither is "just give them more to do," because we're back to ham-fistedly saying "and now, because you're destined heroes, the plot drops in your laps." Or to them accomplishing nothing at all. Not even having fun during the session.

It's not "hand-holding" to want the players to have meaningful options in terms of how to address the setting.

Different strokes for different groups. My group is perfectly comfortable making their own options if they don't see one handed to them. As a personal DM style, I typically like to toss out lots of plot hooks that I'm prepared to run with and I'll wing it if they decide they'd rather do something else.

[Hrugner]

He's well within his rights to keep it secret. Heck, unless the wizard normally geeks out and tells everyone about how magic works, it shouldn't even seem out of character that he shared nothing.

As for the DM, he needs to find a way to make the knowledge useful through some other task if he wants the wizard to expose it. Incorporating seashells into strange murders or the weapons of evil enemies would encourage the wizard to use the knowledge about the shells openly, as well as tipping off the party about their warlock companion.

[Ashizard]

Hey guys, sorry for the late reply. I work at sea so Internet is hard to come by, Thanks for all the helpful tips, ill be sure to mention them in game and get this show back on the road!

(Im still gunna keep collecting souls either way No matter what that Book says!)

[Sigreid]

Hey guys, sorry for the late reply. I work at sea so Internet is hard to come by, Thanks for all the helpful tips, ill be sure to mention them in game and get this show back on the road!

(Im still gunna keep collecting souls either way No matter what that Book says!)

A proper warlock would try to figure out how to siphon some of the souls for himself. I mean, you signed on to do the conch and the prayer. You never agreed to actually turn over the soul...

[RSP]

Why would you want to play a role-playing game where everyone has to play the same characters and no one can have secrets or their own agenda? That seems very boring to me.

I agree that it's up to each player to create a character that has reasons to work with the party, however, that shouldn't equal "every character has to be honest and open with the rest of the characters." You can even create characters that don't get along, that's part of the fun of role-playing, playing out conflicts while working toward a common goal.

Some of the best fantasy characters and stories are based on this very idea; was Raistlin open and honest with everyone? Was Rand Al Thor? Anyone other than Robb or Ned in GoT?

Some characters, most Warlocks and Rogues come to mind, are probably based around keeping secrets. This is part of role playing; you create characters that act in certain ways, with their own motivations. Whether those motivations are secret or obvious are up to the individual players and their characters. If you're not going to allow players to play PCs with different personalities (and act those personalities accordingly), I'm not sure why you're choosing to play a RPG.

[Squeeq]

It seems to me that there are two problems being debated at the same time here, and both of them involve secrets. The first problem is the party member who keeps secrets - they know what may be important information that the rest of the players know, but that their characters don't. This is a problem because it forces the players to stop playing Dungeons and Dragons and start playing How Can My Character Figure Out This Important Information So We Can Get On With Things, which isn't a very fun game. This doesn't matter in more lighthearted RP situations, but when it's something significantly more intense and that players are more deeply invested in emotionally, forcing them to do what they know to be subpar actions is painful and frustrating, which is the opposite of the kind of fun experience D&D should be. Ideally, the player would learn that kind of information in secret, or have it just be automatically known to the party. I consider it impolite to actively state salient information that only one character knows, forcing everybody else to learn the information as players and have to disregard it as characters. Outside of something that is specifically played for comedy, I can't think of many examples where this would be a good, fun decision.

The second problem, of course, is the character that people need to keep secrets FROM. As a personal anecdote, I played once in a game that involved myself as a bard, an arcane trickster rogue, a ranger (I think) and a cleric. The cleric was from a monotheistic elf society that believed that their God Emperor was the real God and that all other forms of magic were evil and heresy. As a result, the rest of us had to pretend that we couldn't cast spells at all or the character would get upset. This was an unendurable hassle, and we spent an incredible amount of time tiptoeing around this other player in order to try and keep the group cohesive. I can't understand why the DM thought that this was a good idea. Something like this is why I think it's important to have a good session zero at the beginning of any campaign, to make sure that the characters will work well (or at least well enough) together. If the player wants to make a character who has incredibly stark lines, that's a source of potential group conflict, and something I prefer not to have to deal with as a player or a DM. I'm sure that there are some people that enjoy some of these aspects, but considering the amount of disgruntled anecdotes that I have seen, I feel like they are likely in the minority.

[Segev]

Why would you want to play a role-playing game where everyone has to play the same characters and no one can have secrets or their own agenda? That seems very boring to me.

I agree that it's up to each player to create a character that has reasons to work with the party, however, that shouldn't equal "every character has to be honest and open with the rest of the characters." You can even create characters that don't get along, that's part of the fun of role-playing, playing out conflicts while working toward a common goal.

Some of the best fantasy characters and stories are based on this very idea; was Raistlin open and honest with everyone? Was Rand Al Thor? Anyone other than Robb or Ned in GoT?

Some characters, most Warlocks and Rogues come to mind, are probably based around keeping secrets. This is part of role playing; you create characters that act in certain ways, with their own motivations. Whether those motivations are secret or obvious are up to the individual players and their characters. If you're not going to allow players to play PCs with different personalities (and act those personalities accordingly), I'm not sure why you're choosing to play a RPG.

This is a bit of a straw man. Nobody has suggested that all the characters must have the same agenda and be on the same page.

What has been said is that having players keep plot-developing hooks secret from the other characters and not even try to figure out how to incorporate the other characters into their hooks to drive the game forward is bad play, because it grinds the game to a halt.

You want to keep a secret? Fine. But use that information. Concoct an excuse to invite the other PCs to investigate what will help your agenda advance. Move the game forward with this information! Don't just sit on it.