How to use, and not to overuse, Insight skill checks?

Question

I've recently begun DMing a 5th edition D&D campaign after a long time of quiescence as Dungeon Master. I really like this new take on D&D, but still, soon a problem has resurfaced, that is: the (paranoid) use of the Insight (or, as of 3rd edition, Sense Motive) skill, and I'm struggling to keep it in check.

I'm curious to hear how you handle this aspect of social interaction. When I'm interpreting an NPC, players often ask me if they can roll for Insight, and soon everyone at the table starts rolling. I'm thinking of outright disallowing such rolls, as (in my opinion) a player should only make a check when the DM calls for it. However, PCs should get to put their skills and proficiencies to use from time to time. So, this is what I've come up with:

1) Let them roll at most once per social interaction. Actually, I should be rolling for them behind my screen, so that they can't do metagame reasoning on a 1 or a 20.

2) Simply do not allow them to roll if they don't know the person they're interacting with to some minimal extent, or in cases where it is objectively not possible to draw a conclusion (for example, asking a guard if he has seen someone they're chasing, and the guard plainly replying "no").

3) Substituting most of the active Insight checks with passive ones. This would mean that the most empathic or intuitive PCs would sometimes sense something is amiss or tension coming from the NPC, or the like.

4) Only allow Insight checks if a PC clearly starts an interaction being suspicious of an NPC, otherwise not let it happen.

But still, I'm really not satisfied. What do you say to a player who failed or succeeded at the roll? To me, Insight should not be some kind of lie detector, but it often becomes one. Have you ever had this problem, too? What do you do?

Answer 1

Do you like your rpg old or new school?

You have asked a question that lies at the heart of the debate between "old-school" and "new-school" rpg. If you don't know what that is, then there are plenty of places on the net where you can have your brain bashed by intensely partisan views on both sides. I don't think its useful to go into this here.

At the core is the question "Who is detecting the untruth?". Is it the player (old-school) or the character (new-school). If it is the character then rolling the dice is a perfectly acceptable way of deciding. This seems to be causing you some cognitive dissonance (your old-school roots are showing ;-) ).

The simple answer

This is where I give you the mandatory and largely useless answer - you are the DM, however you decide to do it is perfectly correct.

Now that that is out of the way, I will tell you what I think should happen.

The complex answer

From the Players Handbook p.6:

How to Play

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.

There is not one single word in there that says that anyone rolls dice. So you saying "... as (in my opinion) a player should only make a check when the DM calls for it" is spot on; nobody rolls dice to resolve anything unless you ask them to. Obviously, in a combat situation, your asking may be implicit but otherwise, the players' should be telling you what their characters are trying to accomplish; they describe the outcome they want, you determine the process. This may range from "You do it" to "Are you kidding me? That's clearly impossible."; its only when the result falls between these extremes that a die roll may be the appropriate resolution.

This position is clearly supported by this paragraph (p.186)

Ability Checks

In addition to roleplaying, ability checks are key in determining the outcome of an interaction.

Your roleplaying efforts can alter an NPC’s attitude, but there might still be an element of chance in the situation. For example, your DM can call for a Charisma check at any point during an interaction if he or she wants the dice to play a role in determining an NPC’s reactions. Other checks might be appropriate in certain situations, at your DM’s discretion

A player saying "I roll an Insight check" deserves the response "The NPC wonders out loud why you have suddenly taken a dice out of your pocket and thrown it on the table. "Do you want to play craps?" he asks.

Alternatively, you can do what I do. Since the player seems to love rolling dice I say "Go ahead" and then completely ignore their roll.

When wouldn't you roll

Going back to the flow of the game:

1. The DM describes the environment.

You know if the NPC is lying or not and, if they are, you know why. Interacting with the NPC should be one of the ways the players can find out if they are lying. It is important that the players know this then there should be at least 2 other ways of finding out (See The Three Clue Rule).

Describe what the NPC says and how they say it so that there are cues that clever players can pick up on to determine if they are lying. Signs of the truth may include "calmly", "quietly" etc. Signs of lying include "sweating", "shifty", "slowly" etc.

If they are lying then look at their deception score (or modified roll if you want to roll) - if its high then give fewer clues than if it is low. Personally, if rolling I would make this roll after the interaction was over; the frequency and obviousness of the cues I give would be based on the NPCs Charisma (Deception) modifier.

It is worth considering what the typical ranges of Charisma (Deception) modifiers are:

• -2 ( 6 CHA non-proficient)
• 0 (10 CHA non-proficient or 6 CHA proficient (L1-4))
• +2 (14 CHA non-proficient or 10 CHA proficient (L1-4))
• +5 (20 CHA non-proficient or 16 CHA proficient (L1-4))
• +10 (30 CHA non-proficient or 22 CHA proficient (L9-12))
• +16 (30 CHA proficient (L16-20))
• +17 (20 CHA expertise (L16-20))
• +22 (30 CHA expertise (L16-20))

A few points to note:

• an average person without proficiency has +0,
• the most charismatic person without proficiency has about +5 - equal to a proficient low level sorcerer
• the most charismatic con-man with a lifetime of experience has about +17

From this, I have the following rule of thumb:

• 0 or less: this person is going to give an obvious sign every time they lie.
• 1-5: this person is uncomfortable lying; general physiological signs and obvious signs if the lie is blatant.
• 6-10: happy to tell lies; minor physiological signs, distortions of the truth are undetectable, outrageous statements may cause them to blink.
• 10-15: accomplished liars, con-men, lawyers, politicians (non-pejoratively of course!), no physiological signs, maybe some slowness of speech as they have to think about the "correct" response instead of the true one.
• 16+: You get nothing.

If it is truly important that the PCs think he is lying just say "You think he's lying"!

2. The players describe what they want to do.

Is it enough for them to say - "We think he's lying?" Well, is it? As a DM my response to that is "OK, but what do you want to do? How do you catch a liar?"

Good players may well ramp up the stakes, you catch a liar by making them say something you know is untrue and that you know they know is untrue (otherwise they are just wrong, not lying). If they can do that, then there is no need for a roll.

What is this "insight" anyway

Let's have a look at what Insight actually says (p.178).

Insight. Your Wisdom (Insight) check decides whether you can determine the true intentions of a creature, such as when searching out a lie or predicting someone’s next move. Doing so involves gleaning clues from body language, speech habits, and changes in mannerisms.

Note: this is stronger than just detecting a lie - it gives you insight into the true intentions.

and for comparison, what Deception says (p.178).

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.

Clearly these are mirror images of each other. There are therefore four obvious alternatives to resolving a conflict between them:

1. Passive Insight vs passive Deception - No randomness at all, basically whoever has the higher bonus wins with ties going to Insight. This allows for no degrees of success or failure.
2. Passive Insight vs active Deception - Equally skilled participants will have a 50% chance of winning and a range of possible degrees of success/failure.
3. Active Insight vs passive Deception - This is the mirror image of No 2.
4. Active Insight vs active Deception - This gives a much wider range of possible results but the general rule is that a choice to use insight actively should not give you a worse result than the passive use so in effect, this significantly helps the insighter (to coin a word).

My preference

If the NPC is trying to deceive the PCs then this is something the NPC is doing deliberately. They should be making an active Charisma (Deception) check - you can do this before play so the PCs don't see you rolling.

Casual Interaction

These are the everyday interactions where the PCs are seeking information and have no premonition that a lie would be told. Have the conversation and give the players the appropriate cues.

If the players actively pick up on the cues (i.e. "He's sweating and stammering, I suspect he is lying" not "I think he's lying") then call for a Wisdom (Perception) roll. Success means that they get insight into the truth ("He says "The dungeon is north of here." but his eyes keep glancing to the west.")

Notwithstanding, their passive Wisdom (Perception) lets them feel that he is lying if they beat his active Charisma (Deception) roll. You tell them this at the end of the interaction - no backsies if they missed your cues.

Remember, this check is against the best PC Wisdom (Perception), other PCs are helping giving advantage (2 rolls on active, +5 on passive).

The Confrontation

This is where they go in suspecting that lies will be told, they should give you a reason why they think this; you are quite within your rights to say that they have no basis for their suspicion.

Here active versus active is probably most appropriate; I may or may not allow the passive value to serve as a floor, probably not as the player has decided to "go on the attack" and has left his "passive defence" behind. However, I would allow more nuanced results. Say succeeding gives the "truth", failing by up to 5 allows identification of "lies" and failing by 10 or more gives "false truth"; you believe the lie or you believe the truth that is not actually true (He says north, the truth is west, you tell the players south).

Play out this confrontation, depending on how it goes Wisdom (Insight) vs Charisma (Deception) may be the go but it could become Charisma (Intimidation) if the PCs threaten, Charisma (Persuasion) if they cajole or even Intelligence (Investigation) if they cross-examine; this allows the players to guide the conversation towards their strengths. In any event, Charisma (Deception) would probably be the response to all of these.

Again, remember to apply advantage and disadvantage as appropriate.

Player agency

Whatever you decide, you must tell the players how it will work; you can and probably should decide with the players. Remind them that this cuts both ways - they will be trying to deceive people too!

As an aside, much the same argument goes for using Wisdom (Perception), but that's another question!

Answer 2

Use different consequences instead of witholding information on a failure. For example, if the party is getting information from a contact in a new city...

Player: "I'm not convinced he's being honest. Can I sense any kind of deception or dishonesty?"

DM, pass or fail: "His gaze is evasive, you get the sense he's not telling you everything."

DM, fail: The same, but then, "He notices your hostile stare and gets angry. 'Fine, if you're not going to trust me, see how far you get in this city without me!' You may be on the verge of losing a valuable contact..."

(I think some sources call this "failing forward," but I've seen conflicting definitions for this term.)

A few more failures like that, and this contact of theirs may just leave them completely.

I prefer this to the withholding information approach because it reduces metagaming opportunities. Consider instead:

DM, fail: "He looks totally legit."

Player: "Well I rolled a two, so that doesn't tell me anything."

Other player: "Fine, I watch him closely for any tells, too!"

DM: "...fiiiine, you can roll for insight too."

I'm not a fan of this play style.

The down side is that this can add complexity for the DM, especially if you're working off pre-made adventures. The up side is that insight checks now require at least some cost/benefit analysis from the players.

Another approach I've tried is to simply enforce a "one thing, one check" rule:

Player: "Can I sense any kind of deception or dishonesty?"

DM: "I'll only let one of you do this check. Do you do it yourself?"

Player: "No. I nudge the cleric and give our contact the side-eye."

Other player: "I watch him closely for any tells."

DM: "Roll for insight then!"

You should absolutely discuss this with your players first though, because this is arguably a house rule. A player with high WIS might be peeved if the fighter beats them to their skill checks and they don't get to do anything useful. Upside: can encourage natural collaboration (eg. in my example, the first player knows that the cleric is the one who should be doing the insight checks). Downside: can cause immersion breaking discussions in the middle of narration (as your players argue about who should do this check or that).

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A commenter asks: how does this apply if the NPC is not lying? Good question!

A DM has a few options here. The simplest is: if there are no real consequences, don't roll.

Player: "Can I sense any kind of deception or dishonesty?"

DM: "You don't detect even the slightest hint of insincerity."

...or:

DM: "His bearing is confident and his voice is steady."

(I try to avoid telling players what their own character is thinking, hence not just saying "you think he's telling the truth." This is a matter of narration style.)

Some players might be dissatisfied, but the fact is you don't have to call for checks for every little thing. The thousand or so steps a character takes around a town do not each require a DEX check! Save your rolls for when there are decent stakes.

Depending on play style, you may simply have "flavour consequences" ie. changes in narration, but not to the state of your world. This might follow the same template for failure I started with:

DM, fail: "He looks perfectly nonchalant. But he notices you staring and starts surreptitiously checking his beard for errant food. It's very distracting."

You might even change the whole tone of the conversation because of it, but ultimately the possibilities available to the players do not change. To many players, this will be a reward just the same as an extra 50gp or plot point.

If the interaction is meant to be especially challenging, you might even have the penalty for failure as described above (risk of NPC becoming unavailable), but no real reward for success except confirmation that the NPC is truthful.

But I am always reluctant to make my players roll for something that only offers failure and no reward, so I tend to stay away from the latter approach unless it is a deliberate part of a longer interaction, where it's balanced out by success-only rolls as well. (This worked well within 4e's "skill challenge" framework, but that's getting O/T.)

Answer 3

Roll those checks hidden from the player

I always allow the player an insight check when they request it, but I ask their modifier and roll them in secret. I do not tell them what (the number) I rolled, and if it succeeded or not. I simply report them the impression the character has, the personal judgement they asked for, based on the roll.

We rolled them openly before, but failure gave too much information to the player (if she rolls a 1, and I say "you trust him", it's too obvious...).

Rolling in secret means that often, they do get valuable information, but it's only an impression, a feeling. And like in real life, you can't always trust those.

I do this for all the checks where the result isn't obvious to the character. My players often use Guidance and a high-WIS character for these social checks, and their success rate is pretty good, but there is always the lingering doubt - as it should be. It's insight, not mind-reading.

Answer 4

One approach here would be to use a group skill check, as detailed on page 175 of the Player's Handbook. Simply: each PC makes the check, and if at least half the PCs succeed, then the whole group succeeds; otherwise, the whole group fails.

This can be explained thematically in that if only one PC suspects something but the rest of the group thinks everything is okay, that one PC is influenced by the trust the others are showing.

Answer 5

Not sure if this should be an answer or a comment... However I have seen it suggested in either a podcast, or some article by Mike mearls, that insight checks when used freely should reveal a flaw , bond, ideal, or trait of an NPC.

For example, is a trait is "addicted to skoom" the insight check might reveal fidgeting, or if there is a bond to some patron, the insight check might reveal colors or symbols on the clothing associated with the patron.