D&D 5E Mysteries, Zone of Truth, and Savvy Players?

[Hawk Diesel]

Partially depends on how violent they are, but one good tactic is to overshare. They can give way too much information, including true but trivial things. Then the players need to roll investigation to notice patterns and discern which things out of 20 are important.

Basically, yammer.

Another way is using riddles or prophecy. The answers are true but still require investigation from the players.

A third option is possession. The party starts questioning the suspect and the BBEG assumes direct control. Maybe the suspect shares one or two critical clues before the BBEG kills them for betrayal.

A fourth option can only be done once. The suspect has a magic item that registers everything as a lie. Even the truth. Even sense motive. It's all comes up as lies.

There's a really good episode of Burn Notice that demonstrates this technique. Luca the Watchmaker/Bombmaker gives Sam Axe a run for his money by providing too much information, but all of it vague and basically continuous misdirects.

Zone of Truth is an interesting spell that can have a lot of world-building consequences, especially if many people exist capable of casting 2nd level spells. One thing to consider is how effective the spell can be when paired with torture. While the spell certainly doesn't compel the target to speak, torture can be really effective in making them speak, with the spell ensuring everything that is said is true. It was something I hadn't considered until a fellow player/DM pointed it out. In his homebrew game world the Great Churches used the combination to weed out heretics.

One thing that could help is to throw in a changeling. Maybe a pair of them even. Their shapechange is mundane rather than magical, meaning it wouldn't show up with magic or normal illusion detection short of true sight. Then the changeling could be truthful in the interrogation, but not point out their disguise, escape after the interrogation, and then basically it's a misdirect because the players are sure it's someone but that person has essentially been framed.

Or it could be that the person who did it was compelled by someone with leverage over him. A kidnapped kid or wife, or something else, and now not only do the PCs need to find the real criminal, but also save the patsy's loved ones.

 

[77IM]

Here's one for your justice cleric: there are so many ways (magical and mundane) that zone of truth can be fooled or subverted that statements made under its effect are inadmissable as evidence. So the culprit could actually confess, but unless you have other evidence or some sort of leverage to make them confess while not under the spell, you have to let them go. It would be like hearing someone confess to a crime on a warrantless wiretap -- you know they did it, but unless you can prove it some other way, you can't prosecute them for it.

 

[Guest 6801328]

Maybe they can’t handle the truth.

 

[Quickleaf]

Here's one for your justice cleric: there are so many ways (magical and mundane) that zone of truth can be fooled or subverted that statements made under its effect are inadmissable as evidence. So the culprit could actually confess, but unless you have other evidence or some sort of leverage to make them confess while not under the spell, you have to let them go. It would be like hearing someone confess to a crime on a warrantless wiretap -- you know they did it, but unless you can prove it some other way, you can't prosecute them for it.

Oh, definitely!

So the situation is actually not in a court room. It's at an auction – I hope I mentioned that above – specifically a black market auction. The PC in question is posing as a bidder. But the item everyone was bidding on was stolen. The doors are guarded by the auction's leader, so no one goes in or out without a fight. The auction leader is willing to cooperate with the PCs to make sure the culprit is found, so the zone of truth can be used, provided questions stay relevant to the investigation. Hope that clarifies!

 

[TheCosmicKid]

Zone of Truth is an interesting spell that can have a lot of world-building consequences, especially if many people exist capable of casting 2nd level spells. One thing to consider is how effective the spell can be when paired with torture. While the spell certainly doesn't compel the target to speak, torture can be really effective in making them speak, with the spell ensuring everything that is said is true. It was something I hadn't considered until a fellow player/DM pointed it out. In his homebrew game world the Great Churches used the combination to weed out heretics.

You don't need torture, you just need command, which is conveniently also on the cleric spell list.

 

[Imaculata]

I would probably have the villain mess with illusions, in order to pin the crime on someone else. You would end up with plenty of witnesses that blame the wrong person, because they swear they saw him commit the crime. The villain could also just refuse to be questioned, and/or provide himself with a credible alibi so the players see no reason to use Zone of Truth on him. Again, illusions can be used to get witnesses to confirm that the villain definitely was somewhere else at the time of the crime. Eye witness testimonies can be unreliable, even when illusions aren't involved.

These sort of mysteries are usually not solved by just determining who is lying. You need to find actual evidence to support people's testimonies. Witnesses can be mistaken regarding who they saw at the scene of the crime, because they didn't get a good look at the suspect, and their memories are unreliable. Only through proper interrogation and investigation can you find out if their testimony is correct. Even with the aid of Zone of Truth, this is still all going to come down to basic detective work.

So as a DM I would recommend to throw in lots of false testimonies, false leads and unreliable witnesses to complicate matters, along with enough clues to sort this whole mess out.

 

[Ovinomancer]

Sorry, but you said this was a black market auction? Why would any of the usual suspects at a black market auction cooperate with magical questioning? Further, it would seem that some might be rather powerful and would react very poorly to being questioned at all.

 

[Li Shenron]

Zone of Truth is hardly foolproof, as anyone who fails the save is aware and can still choose not to answer.

Anyway, this is certainly not about the DM being confrontational against the players, but it's about the genre of the story. What is the point of a murder mystery if the solution is one push of the right button away? What is the point of watching a mystery movie and clicking on wikipedia to quickly check who's the murderer before the movie resolves? How lovely is it when someone tells you how a movie ends before you watch it?

If I were a player in that adventure, I supposedly agreed that we're interested in discovering the mystery the hard way, so I would not play a PC capable of spoiling it all with a click, or I would pretend to forget I could click that button.

 

[Coroc]

We've started a new campaign, and after their first session my players are set up to investigate a mystery of a stolen auction item. My group is comprised of experienced, clever, genre-savvy players, and everyone has some DMing experience. They're a joy to DM for but also a challenge!

One of the players has access to the zone of truth spell, and he has the authority/permission to use that spell on multiple suspects (provided it's limited to questions pertaining to the investigation). I thought I had the mystery well designed so that zone of truth wouldn't break it, but now that I have more time to reflect on my players' skill level, I may need to think this through more.

In the past, when I've run a mystery for other less experienced players, I was able to use evasive answers and counter-questioning to trip them up with zone of truth. I even managed to confound one experienced player during his first casting of zone of truth (the questioned killer had given the familiar of a spellcaster poison to sprinkle in the drinks of the murdered, claiming it was tea). Those tricks worked because of lack of experience – either generally or with the spell. However, these players are far too experienced to be tripped up so easily.

EDIT: For instance, I'm fully expecting "answer in yes/no format only" or "repeat after me" strategies.

Have you successfully run a mystery for experienced genre-savvy players? How did you handle intelligent questioning via zone of truth?

Use a Geas to counter the zone. The stolen artifact has a hidden property to conceal itself with an advanced form of Geas, preventing the NPC who might know meaningful clues to answer directly to questions about its whereabouts, eve nwhen under the influence of zone of truth or charm spells.
(The NPC will take damage if he tries to break the Geas)


Edit: oh I just saw @Theo R Cwithin came up with that idea already

 

[Krachek]

In a Players vs DM contest Zone of truth will be almost useless the DM willingly want to give some clue to the players,

If you use the Npc vs Pc point of view, the same contest can give very interesting result, especially if you allow the Npc to have bond, flaws, doubt and fear, and will to save his ass.