What are the uses and limitations of Persuasion, Insight, and Deception against other PCs?

Question

Yesterday, I was in a D&D 5E group. Today, I am not. We were playing Out of the Abyss, but that's redundant to my issue, I think.

Basically, the DM and I are interpreting Insight differently. He believes insight is used to determine if you believe someone or not; i.e. "Roll high, you can tell if they are lying or not. Roll low and you have no reason to not believe them (aka you believe them)". Persuasion and Deception determine how well you make someone believe what the character is saying. In this case, it was a PC deception against PC insight.

A player character rolled for deception, saying it was deception aloud. I rolled low on my insight, therefore by DM logic, my character full-heartedly believes him without a doubt. I challenged him, saying that I don't want to believe. However, since it was OOC revealed that the Player Character was under a charm persuading others to believe that the demon in the castle was a friend of his, my disbelief would be meta-gaming. Therefore I have no control over whether my character believes or not. My character believes in him because my insight roll was too low to tell he's lying.

I wrote a whole essay on this arguing against his logic, but in the end, he stated "if a character cannot be persuaded/deceived into doing something the player doesn't want them to do, deception and persuasion have no use. Meta-gaming would run rampant."

Which interpretation is more accurate to the spirit of D&D 5E? Which is more supported by evidence? Which is better for the health of the player and GM? Should this be GM discretion to decide?

Answer 1

This is something you'll have to settle among yourselves.

Everyone plays D&D a bit differently, sometimes more than a bit. There are groups that go to extreme lengths to maintain a hygienic distinction between character and player knowledge to avoid "metagaming", there are groups that feel the game only improves by allowing players to leverage any knowledge they have, and there are groups that go anywhere in between. (and this is just one of the countless variations between D&D tables!)

There is no single "spirit of D&D 5e", and no single correct way to play with the character knowledge relating to the use of these checks. Words like "metagaming", "railroading", "immersion-ruining" etc are often used to disparage certain playstyles, but are seldom accompanied by justification over why these things are discouraged and in what instances.

It sounds like you and your GM both are equally convinced that your respective ways are each the one correct way to play. That is an argument we cannot resolve for you, because there isn't a single fundamentally correct way to enjoy D&D --- as far as I'm concerned both of your interpretations on what D&D is supposed to be like are equally correct.

Every way to play is correct as long as everyone around the table enjoys it --- although some ways are definitely easier for most people to enjoy (or learn to enjoy) than others. But playing two different games at the same table is very rarely enjoyable. That's why, in the future, you need to ensure you're playing the same game before these conflicts occur, and prepare to talk about what kind of game you're trying to play when they occur anyway. You will inevitably have to make concessions at some point, but that is the cost of any group activity --- it's hard to find five-ish people who are always in perfect agreement with you.

A popular tool for these discussions is known as the Same Page Tool. It looks like a questionnaire, but should be treated as discussion prompts for the entire group (every time I've used it as a poll has ended in a bunch of unresolved conflicts that emerged later in gameplay). It's also not something you should vote on --- if people disagree, the best course action is to talk out the disagreement and see if either side is convinced. If the point isn't important to you, concede. If you can't reach an agreement over an issue you deeply care about, look out for a game group that matches your tastes better.

Session Zero is a good place to have these discussions. Even though its name might imply that it happens before the first session, it's not too late to have a session zero now, to realign with the rest of your group about what kind of game you want to play. In fact, I try to personally arrange some "mini-session zeros" with all actual sessions, for discussing what worked, what didn't, and where people want to see the campaign develop.

Summa summarum, this is a problem between you and your GM, your respective expectations of the game not aligning, not a problem in either of your interpretations. If you don't want to let go of your interpretation, and the GM not of theirs, you should find someone else to play with and hopefully help yourself and them discuss your expectations of the game in terms that allow you to avoid or resolve such unpleasant conflicts in the future.

Answer 2

The DM is wrong here

As the DMG explains on page 237, a roll is called for by the DM when the outcome is in question.

Unless forced not to by magic (ie. something that explicitly overrules this) you have agency over what your character believes. If you state that you do or do not believe what someone says, there is no room for a roll, as the outcome is not in question.

As there may be clues that are available to the character, but not the player, you may ask the DM along the lines of "Does he seem sincere?". Thus you indicate that the outcome is uncertain (ie. you didn't simply decide) and then the DM may call for a roll as appropriate. As you (the player) are already uncertain, no result will feel like it is forced on you.

It is also important that in any situation arising later, you still have agency over what your character does with the information he has. Believing or not believing what someone says at one time does not automatically force any action on you.

I further have to note that rolling social checks against other PC-s is often straight-out prohibited. This, however, depends on the table, and is not written in the books. At least not in the books for D&D 5e, in other systems like Savage Worlds or Shadowrun (5e) success or failure on skill rolls like Persuasion result in a change on an "NPC attitude chart", something that clearly has nothing to do with PC opinions. This approach futher underlines your agency over your character's beliefs and mental state. While I am personally ok with intra-party rolls (when handled properly), I believe the existence of this mode of play says a lot.

Answer 3

This is an issue best resolved by discussion. They want to run a story with a traitor among them. You don't want to run that story.

The basic rules (SRD) description for the Deception skill reads:

Deception

Your Charisma (Deception) check determines whether you can convincingly hide the truth, either verbally or through your actions. This deception can encompass everything from misleading others through ambiguity to telling outright lies. Typical situations include trying to fast-talk a guard, con a merchant, earn money through gambling, pass yourself off in a disguise, dull someone's suspicions with false assurances, or maintain a straight face while telling a blatant lie.

As it notes, you are hiding the truth from others. You don't actually change what they believe. Your character has no evidence from a skill check of their treachery.

As others have noted, you have control over what your character believes, and an insight roll just determines if you can gain evidence of treachery. I have had games like that, where one player passive aggressively tried to reveal the other player repeatedly. Your gm's plans are not good, since you are not working with them.

As such, from personal experience, what works best is if you talk with them. Are you worried about some bad storylines from betrayal? Death, or loss of magical items, or failure of the mission? You should talk to the player and the dm and see if they can convince you that the traitor plotline will be fun and not hurt you in a severe way. PvP is fraught with these issues, so open discussion is vital. I have played through a lot of fun enemy mind control sessions after a fun discussion where we agreed what the possible consequences of treachery are.

Answer 4

There is no "right" way to play D&D

Okay, let's go back to the basics.

The play of the Dungeons & Dragons game unfolds according to this basic pattern:

1. The DM describes the environment.
2. The players describe what they want to do.
3. The DM narrates the results of the adventurers’ actions.

The DM might (but don't have to) ask you for an ability check between steps 2 and 3. Players do not declare checks, it's the DM's call. You describe what your character does or says. A DM might ask you for a check before narrating the outcome.

A game might not involve social checks at all! See the DMG page 236 "The Role of Dice":

One approach is to use dice as rarely as possible. Some DMs use them only during combat, and determine success or failure as they like in other situations.

Another possibility is asking for a roll for anything:

Some DMs rely on die rolls for almost everything. When a character attempts a task, the DM calls for a check a picks a DC. As a DM using this style, you can't rely on the characters succeeding or failing on any one check to move the action in a specific direction.

Both approaches are equally valid. It's up to the DM what playstyle do they choose. Making arguments and appealing to the rules does not help here. If this particular DM's playstyle does not suit you, give a feedback after the game. Say you were not having fun, explain why. A good DM tends to listen to players.

Your particular DM is kind of radical tho

In the worst case, he might be a competitive control freak, who is trying to get a win against players. I hope he is not, however. It is possible that your DM simply has a different background, which is not very compatible with the 5e mentality. Let's see what was wrong with his approach.

In 5e, characters do not "use skills". There is a variant rule in DMG that does not need skills at all. Instead, the proficiency bonus is determined from the character's background. That's correct, you don't "use" your Persuasion. There is no term "skill check" in 5e at all. There is Charisma (Persuasion) check — it is an ability check that adds your proficiency bonus if you are proficient in Persuasion. It is an optional check, the DM might ask you for it when you "try to influence others".

Now, let's analyze the DM's argument:

"if a character cannot be persuaded/deceived into doing something the player doesn't want them to do, deception and persuasion have no use"

That's simply not true.

Rules as written, deception doesn't allow you to force people into believing any bullsh*t you say. It allows you to hide your true motive from the listener:

Your Charisma (Deception) check determines whether you can convincingly hide the truth

Chapter 7: Using Ability Scores

So, when you lose the insight/deception contest, your insight fails, basically. You do not automatically believe anything that was said. Even magical spells like Suggestion do not have such power — they require the words to sound "reasonable".

Persuasion is not magic as well. It can't magically change creature's beliefs, regardless of the roll (if there are opposed persuasion rolls, which I am not aware of). Interpreting it in such ways will significantly decrease the value of mind-affecting spells.

Players do not require a DM in order to to talk to each other

When you are talking to each other in characters, I suggest you not to use dice at all. Instead, just talk! When one PC is talking to another PC, and there're no NPCs around, DM is not involved at all. Therefore, he (she) does not need to ask for ability checks.

Asking for checks and saying to players, what do they feel or think, is a bad practice that can easily spoil the fun. Players can handle this by themselves. Also, it is a great opportunity for actual role playing, which should not be missed.

Answer 5

RaW, your PC does not know if the other PC is lying or not. Your PC should behave accordingly.

Metagaming: Most tables avoid meta-gaming. So you (as a person) knowing that the other person is lying or not is irrelevant. What matters is what your PC believes. It seems clear to me that your DM wants to avoid meta-gaming at the table, and if you do not agree with that, then the rest of this answer is moot. Other answers in this question focus on this point, and they suggest good tools to get you all on the same page.

The liar being a PC doesn't matter: Let's forget that the other guy is a PC, it's irrelevant. Assume the other guy, let's call him Bob, is an NPC controlled by the DM. When Bob says something, your PCs may question his veracity. So the DM tells you to roll your PC's Insight against Bob's Deception (if he was, in fact, lying).

If you fail this contest, then your PC does not see any signs of lies in Bob. He doesn't know whether Bob is truthful or not. But remember, your PC also does not know that he rolled low, it just doesn't interpret well Bob's body language.

So what does your PC do? What he usually does. If it is a naturally trusting PC, it believes Bob. If naturally suspicious, he doesn't trust Bob. Or something in between. You choose how your PC reacts.

But if your table does avoid meta-gaming, then you will usually believe what your party members say, I think? Maybe this is the point of your DM when he says you believe Bob. You're friends, and your PC doesn't usually second-guess your scout when he claims There's a trap ahead, stay still!, so why would you doubt Bob?

That being said, as a DM, I really avoid PvP checks. It often leads to problems like these. I have experienced players now that can separate the player and PC knowledge, and do this in good fun, Stealth vs Perception, usually taking chunks of gold from each other and returning them later as booze acquired at the tavern. They call the rolls themselves, and laugh it off as players. But it took years to reach this point.

Answer 6

Rolls are only for when the outcome is in doubt.

PHB pg. 171 under Ability Checks:

The DM calls for an ability check when a character or monster attempts an action (other than an attack) that has a chance of failure. When the outcome is uncertain, the dice determine the results.

When a player character is attempting to persuade somebody else's character about something, it's up to the player to decide whether or not the outcome is in doubt, not the DM. If I know my party rogue is a lying, thieving bastard, I don't care how high he rolls on deception I know it's extremely likely he's lying and I will not believe him.

As for this:

"if a character cannot be persuaded/deceived into doing something the player doesn't want them to do, deception and persuasion have no use. Meta-gaming would run rampant."

No. Those have plenty of uses still. There is a world full of NPC's out there, and they WOULD be rolling against the players because the DM is setting their roll numbers. You don't know if the sketchy NPC is actually telling the truth or not. You can declare that you think he's lying, but that doesn't reveal that he is. Here's an example of how that works:

• NPC tells party about a secret treasure location far away from town in a secluded Oasis. He asks them to fetch them a seemingly insignificant bauble from the treasure, but tells them they can keep all the rest as a reward. However the treasure has a fearsome guardian.
• Player doesn't believe NPC. Declares, "I think he's lying."
• DM has player roll Insight. The NPC isn't lying, but the DM doesn't bother pointing that out.
• Player rolls a 27. He smiles and says, "Alright, is he lying?"
• DM says, "He appears to be telling the truth."
• Player says, "I don't believe him."
• DM says, "Ok, you think he's lying. Are you challenging him?"
• Player says, "Sure. I'll call him a liar to his face. Tell him that I'm really good at reading people and he's hiding information."
• DM, "The NPC laughs out loud at you, and then pointedly ignores you to address other people in the group who still seem interested in the information."

As a player, if I'm not sure how my character would react, then I would leave it to the dice. However I would also set the DC since I would have a vague idea of what ballpark the claim is in. If somebody was telling me the location of a treasure and I suspected it was a trap because of the copious amounts of bounties in the area, I would likely set that particular DC really high to be convinced that it was a legitimate quest and not bait.

Answer 7

There are definitely larger issues here about how to use the social influence mechanics between PCs, and this depends on your group's play style. However:

This is a protocol mistake.

A player character rolled for deception, saying it was deception aloud. I rolled low on my insight, therefore by DM logic, my character full-heartedly believes him without a doubt. I challenged him, saying that I don't want to believe.

If you "don't want to believe" then you shouldn't have rolled.

Let's crudely classify the two approaches to social skills as Dice Mode and Talk Mode. In Dice Mode, "influencing people" is one of many things your character knows how to do, like disarming a bomb, riding a horse, or casting eldritch blast, that you don't necessarily have to know the first thing about. You announce that you're doing it, and describe the approach you're taking, and then you apply the game mechanics to simulate your character's attempt to make a convincing argument.

In Talk Mode, you make the argument yourself, and another player (possibly the DM) judges whether their character would be convinced by that. (They might or might not consider whether they personally believe it--separation of OOC knowledge and motives is a related but different element of play style.)

There are advantages to using either mode but the distinctive feature of Talk Mode is that it preserves your agency. Your character's decisions are always entirely in your hands.

"I'm making a Deception attempt" is a clear sign that the other player is trying to handle this in Dice Mode. If the DM tells them to roll* then the DM agrees. If your response is that you "don't want to believe" then you're trying to use Talk Mode: the player hasn't made a convincing argument, so you intend to play your character as not being convinced.

But you need to make that objection before dice actually get rolled, and especially before you pick up the dice and roll. By rolling your Insight check you are committing to accept the outcome.

The basic function of dice in RPGs is to provide finality. You can talk and banter and it's all hypothetical and changeable, but once you roll dice you're committed. You've collapsed the probability wavefunction--what was a "35% chance of success" is now a definite outcome. When Julius Caesar defied the Senate's orders and marched his army into Italy, he said "Roll the dice."

And after you've marched your army into Italy, it's too late to say "I think I shouldn't have to fight the Senate."

*This is one reason why the DM should be prompting players to make skill checks instead of them just rolling dice all willy-nilly.

Answer 8

Social skills suffer from a general problem

1. There is a basic difference between all skills related to talking and the mind and all physical and magical skills. The players sit around a table and actually talk to each other - but they don't climb/fight/wizard, we just describe them doing this.

2. DnD is a game where high-level skills can achieve unbelievable feats. A high level rogue can "hide in plain sight", a high level speedster can run faster than the fastest human on earth. So why should it be unthinkable that an epic-level trickster could actually talk you into believing almost anything? Like the other examples it is "just" another unbelievable feat.

3. Many people like roleplaying games, because they can be someone and do things they cannot in real life. If a physically weak person wants to play a super-strong barbarian he can. If someone wants to play a wizard and do magic he can. And if someone who is not really good with words, wants to play a very eloquent and persuasive social character, he should be able to do so.

Out of character knowledge is a slippery slope

If a player tells you "My character wants to trick your character into believing this demon is his friend" you already know the truth as a player. It is usually really difficult to objectively reason how you would have played your character if you didn't know the truth. - I think this is what your DM wanted to imply when he said "if you attack this demon now, despite everyone telling you he is a nice person and no threat, and your character has no reason to believe he is actually evil, then I will remind you in the future when you meet other demons, which are actually nice and very important for the group, because why wouldn't your character attack them too?"

If your character has low scores in intelligence, insight / social skills, it would feel somewhat unfair, if you could just make up for these by being a smart player with a silver tongue. A physically strong player cannot just lift up the gaming table and say "see I don't need to roll strength, let me just succeed" - basically a roll will determine if an action succeeds or not. And if the roll succeeds (and the difficulty was set accordingly) then the character has actually found a way to persuade your character.

New information might change the result

Of course every time your character receives new information, you can ask your DM if you get another roll to inquire more and maybe see through the deception. If the charmed character acts very strange, or you hear from villagers that the demon has killed innocent people, there should be another increasingly difficult deception vs. insight roll to keep up the lie.

I think the group should work together to come up with witty arguments and a believable story, how the character actually persuaded your character, so the game world still feels right. Just like the DM usually describes how other hard to believe skill-checks (natural 1/20) play out, you should have enough imagination as a group to tell a story which matches the dice.

But this is just one way of playing the game

As the other answers have pointed out, there are other ways of playing DnD and non is right or wrong, as long as it fits the group. You may of course decide on never rolling PvP, or never letting any social-skills or mind-control interfer with player agency. Some groups ban mind-bending magic completely from their game (or at least vs. players) because the players do not want to give up control over their characters. None of these is wrong, if the group enjoys it.

But I wanted to point out the (maybe unwanted) consequences of playing a game where most social conflicts between characters are decided by the verbal skills of their players. The characters of verbally adept players will have a big advantage and verbally inept players will probably not feel happy playing a social character.

Answer 9

I'm a latecomer to this question, but I think I still have a couple of worthwhile things to add. So please think of this as an "in addition to" the other answers here:

The situation you are describing is filled with problems for what the DM seems to have wanted to do.

As others have mentioned it seems that you and the DM were working towards separate games/playstyles which didn't mesh together well. I think that that's true, but even if we're maximally generous to the DM some of the choices they made at the table seem to cut against the game they seem to have wanted. Those choices made it impossible for either of you to get what you wanted.

• The PC who wanted to deceive the rest of you should not have announced to the table that they were trying to deceive the other players.

It's difficult to separate player and character knowledge, and doing so isn't everyone's idea of a fun game. For intra-party intrigues, players should work individually with the DM. That way the DM can track any relevant information and allow all players to discover that part of the story just like they would any other-- by playing it out. That's how I've run my games, and it's how I've managed secretive characters as a player.

• If you had an outcome for something over which you have complete agency (like your character's ideas and feelings) pre-selected, you should not have rolled a die.

As other answers have already pointed out, dice are for situations where the outcome is uncertain. Rolling a die implicitly indicates that you will abide by the roll, just like on any other ability check. You can't (outside of a couple of very specific instances) make an attack, decide that you don't like your too-low-to-hit result, and then declare that you've hit after all.

It's also far from impossible for people dead-set on an idea to be snookered. For a real-world example, many people go to high-pressure sales events (like for timeshare properties) pursuing some free promotional item and firmly intending not to buy anything at all. And yet some of those people end up being persuaded (or bamboozled, confused, etc.) into buying something anyways. A character's ability to resist that kind of pitch is encapsulated by their ability scores and skill proficiencies, so if it's that kind of situation a roll might be plausible. But I avoid them-- unless players are specifically interested in a roleplaying challenge featuring dramatic irony, I've never seen rolls modifying character opinions work out in a fun way.

• If separating what players and their characters believe is an important element, and you are relying on a character's (not player's) ability to discern the truth, it makes more sense for the DM to do a hidden roll.

I use this one sparingly as a DM, because rolling your own dice is part of the fun of these games for me. But rolling a die, seeing the outcome, and then hearing the narration reveals a ton of information about the broader situation. It's hard for the player to pretend they don't know what they do, and hard to suggest that the character shouldn't have any inkling of what the player knows.

Since the issue at question is how well your character discerns the truth of a situation, it makes sense to evaluate the effort based on who knows what. In this case only the DM and the lying PC would know the truth, so the DM should know the DC and your character's roll result. If, conversely, you had picked up some clues suggesting that the information the lying PC was providing was likely not true, it might be more sensible for you to make the roll because that knowledge gives context to how plausible they found the information.

• Sometimes characters mess up, and knowing the truth doesn't necessarily make for a fun game. But a fun game is what everyone is looking for.

In the same way that an attack can miss, despite a player wanting it to hit, sometimes a character can be deceived, even if the player wants them to know the truth. That's the whole reason these games have character sheets, ability scores, skills, dice, and so on: the characters are different from the players, and have different capabilities and limitations.

I've run into situations where my GM accidentally mis-narrated something, and the extra information would have changed the choices I'd made earlier had I known it. But rolling back events either wasn't possible or would introduce problems of other information I'd gained (like positions of enemies I wouldn't have discovered using my alternate choices). In those cases I tried to keep my character on-plan for what they "knew" as much as possible, but it's hard. And worse, the surprise elements the GM planned didn't come off as intended, and there's no way to recover it once the surprise was revealed.

But I'll also mention that knowing the real truth in-game is overrated, especially compared with discovering it. I find it fun to piece together clues and gain information that helps me make better decisions. But I do not start a campaign DM-ed by someone else by immediately reading the campaign module so that I'll always know the truth about all NPCs and therefore have my PC make the "right" decisions.