Skill Challenge: Lie To Me

by Ameron (Derek Myers) on March 15, 2010

Training in Insight does not make you a human lie detector. Too often in D&D a PC rolls Insight and on a successful check knows immediately if a person is lying. This shouldn’t always be the case. Sometimes you need to work at it. If you’ve never met this person before how do you know that they’re lying. Everybody lies to some extent. Figuring out if the lie they just told you impacts your current line of questioning or not requires work.

For situations where more than one simple roll is required, a structured skill challenge may be more suitable. This is not to say that every attempt to detect a falsehood requires anything this complex, but it might be a good idea to remind the PCs that sifting through an intricate web of lies often takes time and many skill checks.

The setup provided below requires the PCs to interview many suspects. Most are innocent. Strong-arming or threatening them may not be such a good idea. Their actions during this investigation will have lasting consequences so they should proceed cautiously.

Creative PCs may opt to use rituals as part of their investigation. See Using Rituals In Skill Challenges, the section describing the Discern Lies ritual in particular.


  • You are present at a large gathering or party when a crime is committed. A valuable item is stolen from a guest or someone is killed. You have no motive and are immediately cleared of the crime. Since you are impartial to the local politics, you are asked to interview the guests and determine who’s guilty.
  • While travelling aboard a ship a valuable item is stolen or a passenger is killed. You have a rock solid alibi and are asked interviews the passengers and crew to determine who is guilty.
  • Your reputation for order and honesty precedes you. After a prominent noble is killed you are asked to interview the suspects to determine if any are guilty.


Variable. Determine some key points that the PCs need to discover before they can draw a reasonable conclusion (even if it’s not the right one). Let them continue asking questions and interviewing people until they want to stop. For each clue uncovered count it as a success. Add up the successes and award XP appropriate to a skill challenge that would normally require that many successes. If the PCs accumulate 3 failures then they fail the skill challenge. On the third failure provide overwhelming (and false) proof that atruely innocent person is guilty.


Variable. If the PCs know the people they are interviewing, are from this town, city or province, or have a reputation in these parts (good or bad) then the level shouldn’t exceed that of the PCs. If the PCs are new in town then the level should be at least 2+ levels above the PCs.


Bluff, Diplomacy, Heal, History, Insight, Intimidate, Perception, Religion, Streetwise

PCs are likely to use Insight and Perception more than any other skills during this skill challenge. It’s important for the DM to ensure that these skills are not used interchangeably. A successful Perception check might let the PC notice a nervous “tell” during an interview, but Insight is required to understand its meaning. Perception should only reveal absolutes: A person fidgeted, stuttered, scratched their left ear, or looked down and away. Understanding what these clues mean requires Insight.

Bluff (moderate DC)

Claim to know facts that you really do not.

Bluff (hard DC)

Use your glib tongue and fast-talking to confuse the subject.

Diplomacy (moderate DC)

Sympathize with the subjects. Earn their trust through kind words.

Heal (hard DC)

Convince the subject that repressing painful memories is harmful. If they tell the truth they will feel better.

History or Religion (moderate DC)

Convince the subject to do the right thing and tell the truth. Use your knowledge of their sense of duty and honour, societal laws or religious beliefs to earn their trust.

Insight (moderate DC, assist)

Sometimes instinct is more accurate than logic. Trust your gut.

Insight (hard DC)

Interpret body language or other unusual behaviour observed during the interview.

Intimidate (hard DC)

Use threats in an attempt to extract information.

Perception (hard DC)

Listen for auditory clues, changes in inflection or unusual language.

Perception (moderate DC)

Watch for subtle clues when you’re conducting your interviews including facial expressions and body language.

Streetwise (easy DC, assist)

Ask around and learn more about the subjects before interviewing them.


After asking the right questions, corroborating the stories and weighing the evidence, the PC make an accusation that they believe is correct. If they’ve successfully completed the skill challenge then their decision is likely to stand up to the proper authorities.


The PCs were so quick to jump to conclusions that they accused the wrong person of committing the crime. If the wrongly accused can prove their innocence quickly enough perhaps the PCs will continue investigating and try to find the truly guilty.

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1 Kensan_Oni March 15, 2010 at 10:55 am

This has nothing really to do with this article, mind you, but in my last game session, I was using Insight as a defense for a riddle contest. The player got to choose one of their knowledge skills (Or Bluff checks if they wanted), and they targeted the monster’s Insight check, and visa versa, to try to solve a riddle.

I mainly did this because I wanted a riddle contest, but I didn’t want to take forever doing it, and *i* am not clever enough to figure out a lot of player riddles rather quickly. It worked out well, I think.

2 Scott March 15, 2010 at 7:48 pm

You know, I never really considered this before until you brought it up, but the way Insight vs. Bluff works in D&D has almost no actual bearing on how truth-telling works in real life. Research has shown that the VAST majority of the population (99%+) have little or no ability to tell a truth from a lie when exposed to a liar – their response is no better than a coin-flip. It is only that tiny fraction of individuals (0.25% or so of the total population) that has any natural ability to discern a lie. Even with extensive training, the results for your average person do not improve in any remarkable way.

Yet, despite the fact that I know all of this, when I’m running a D&D game I very often will tell a player with a good Insight check, “Yeah, he’s lying.” It seems like this is one of those suspension of disbelief issues that we come across – movies, books, tv shows, video games, fiction in general all seem to make extensive use of make-believe characters who have truth-telling ability that borders on the supernatural.

3 Paul March 15, 2010 at 7:51 pm

Believe it or not, I was just thinking about this. Important lies are complex enough not to be undone with a single check.

One thing I considered was requiring each Insight check to be “unlocked” by some other check. However, if one doesn’t want to get this complicated, one could just do something like just having the liar avoid the PCs or try to bump them off if they get nosy.
.-= Paul´s last blog ..pdunwin: @DM_Simonides I’m interested in details if you have a place to post them. Like to help, if I can. #dnd =-.

4 Ameron March 17, 2010 at 12:26 pm

Sorry for the delayed responses, I’ve been sick for the past few days.

I think this is a great way to use Insight. I’m a big fan of puzzles and riddles in D&D, but it’s tough to separate player knowledge and character knowledge, especially if the PC has an 18+ Wisdom or Intelligence. That PC would likely know the answer of be able to figure it out quickly; meanwhile the player is completely stumped. Keeping the puzzle more abstract and using Insight and Bluff is an excellent way to keep things moving.

I understand introducing a mechanic into D&D so PCs can ferret out lies, but this is one of those cases where a little reality has to be injected into the fantasy. Sure you get a “bad vibe” from someone, but that might not mean they’re lying. I find that too many PCs assume that a successful Insight check means they should know definitively that they were just lied to. Of course, there will be circumstances where it’s obvious, but these should be the exceptions and not the norms.

I like the idea of unlocking aspects of the lie with another skill and then using Insight to realize what it means. This is how I (try to) use Insight in this circumstance.

5 Cedrick November 22, 2010 at 10:04 pm

I just recently started DMing and couldn’t agree with you more. I hate that PC’s think that good insight or sense motive rolls let them know that they’ve been lied to. It shouldn’t be that easy. You can tell that the person is up to no good, or isn’t an honest person, but discounting something they said as lies shouldn’t always be the case.

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