First of all, I know there's been a question titled Crime Investigation in a fantasy world. My question is only partially similar to that, though.

The problem: In a DnD3.x based world (including Pathfinder), there's a good chance investigators and witnesses shouldn't believe their eyes, ears, etc, thanks to various mind altering, illusory, and morphing powers, abilities, and spells, employed by various creatures as well as characters possessing them.

Example: Witnesses claim they saw the Duke of Erehwyna pull a dagger and stab the King to death. (Or: witnesses claim they saw the lowly bartender club a patron to death.) The Duke (or the bartender) claims to have been fast asleep when it happened, though. However, investigators know that there are shapeshifters in the Enemy's employ, that there are low level spells that would allow a wizard to take on the appearance of the suspect and fool the witnesses who don't know him too well, or perhaps that there are five stab wounds despite the fact that witnesses claim the Duke made only three attacks, so an invisible agent could have been involved as well.

What methods can investigators utilize to find the truth of perception-based evidence in a D&D3.x based world (preferably besides True Seeing and lie detection spells, which they may not have access to)?

Secondary questions:

How common is the knowledge about the existence of such abilities, powers, etc. in your typical, classic D&D3.x based world? (If it's not common knowledge, character assassination - painting someone as a criminal - gets all too easy. "I've seen him murder the King! He's a traitor and a murderer!" If it's all too common, crime becomes much more tempting for the immoral: "Oh, I haven't robbed those merchants, it must have been a shapechanger, or an evil wizard who stole my visage!")

How common are the skills, abilities, etc required by the method described in your answer, and how aware are criminals of them (so that the more brilliant of them can prepare to counter them)?


4 Answers 4


At the end of the day, D&D is a very poor fit for these sorts of games, as it's model for everything except combat is either "roll that skill check" or "a wizard did it." In summary, witnesses are worthless, gather information, survival, and search are useful skills that either attack flat DCs or the opponent's bluff, Ebberon's Urban Tracking is essential to enable these sorts of adventures, and Detect Thoughts cuts through about 99% of the paperwork of a trial, and is a very common second level spell.

From a criminal justice standpoint, mortal-based evidence is all sorts of suspect. At the end of the day, like most investigations, it's one side's resources and expertise against another. It's genre specific though, so if your genre presupposes daring feats of thievery, they're possible.

We will presume that the group is interested in this sort of thing, and the game will therefore not feature the Omniscificer who, at level 4, can know every finite fact about the universe (including who did it. For completely arbitrary values of it.)

The first, and most boring route is actual forensic investigation of the evidence. Search provides clues at a location that are a function of the investigative technology of the genre. Note well, "evidence" is not actually useful as a discrete thing. There are skills (gather information, search, survival) that allow abstraction across multiple "clues" for tracking, and the whole idea of a jury trial which provides for witnesses and evidence is manifestly silly assuming access to a third level caster. There are no mechanics for the subsidiary questioning of evidence in a courtroom, nor is there need for it. Evidence allows a nominal perp to be found, not convicted, and all of that "tracking" is abstracted away from the game, to better allow an exciting battle at the end.

Beyond search, an investigator with the track feat can use Survival to track tracks back to the tracker's lair. There exist feats in Ebberon (Urban Tracking) that use Gather Information to the same effect.

Given that the DCs go all the way up to 20, (call it 30 what with one thing and another) and don't scale with the thief's skill, any sufficiently motivated constabulary should be able to find the target without resorting to divinations. In a high-magic game, CSI squads would all be issued magic doodads (keyword "Enhance!" that provide game-specific bonuses to skill checks. An item of Divine Insight made by a high level cleric of the god of justice would fit well here, But is rather overkill.)

So, presuming this, the rules overwhelmingly favour the investigator, save for the unfortunate fact that when they show up at the Murderhobo's adventurer's hideout, they'll be murdered by the PCs.

The second major route is personal evidence. While witnesses are completely without worth, there are a couple of ways of asking "did you do it?" and being pretty sure of the answer. For the overwhelming number of (non-stupidly high level or optimised cases), once you've followed the perps to their lair, and "arrested" all of them, stick them in a "normal" jail for a while. Normal, in this case, being a jail that ensures that they can't regain spells and ensures that all of their normal buffs will have worn off. Then, simply, they're brought before a Level 3 magistrate (cleric or wizard or bard) and asked to let them probe their minds. Happily, there are no constitutional protections against self-incrimination in D&D, and I doubt that even lawful good societies would accept a nominal right to privacy considering that the idea, itself, is an extremely modern concept.

Therefore, the magistrate casts detect thoughts, and calmly asks the person under suspicion to allow the probe (in whatever lingo of the day.) Detect Thoughts is a level 2 spell, Whether knowledge of "core" level 2 spells counts as Common knowledge is a function of the tropes embraced by the game, but given that this is an acceptable and rather more humane form than typical of justice, it shouldn't come as a shock.

Refusal to "open your mind" is taken as a confession of guilt and the sentence is carried out. Once detect thoughts is properly calibrated (3 rounds of glaring at the perp), the perp has to beat a DC 100 bluff check to disguise their surface thoughts. Without access to magical resources, only the most elite will be able to do this (nominally through the use of some sort of prestige class.)

Unfortunately, while there are ways of gaining positive evidence of truthiness via spellcasting (detect thoughts, etc..), the best non-castery way of doing this is via the hunch trait of sense motive, which provides a "Alternatively, you can get the feeling that someone is trustworthy." Sense motive is useful to detect traces of magical coercion (DC 25, sense enchantment), but again, is made obsolete by detect magic. Fundamentally, the investigative aspect of law enforcement is sufficiently rare in a fantasy society to allow for dedicated "experts" to do it. (For a low-magic exploration of this, see Four and Twenty Blackbirds), by Lackey.)

Which leads us to the third, and most depressing way of crime fighting.

"God, did the perp commit this crime?"

There is a huge list of spells that do this.

  • Identify Transgressor, which is somehow evil, gives a 70% correct answer. To get a 95% confidence interval, A panel of 3 drugged judges must each cast this spell.
  • Probe Thoughts, higher level, can be used for things that are conevably within the interest range of high level characters.
  • Susurrus of the City, worth enchanting into an "intentionally" abandoned building, allows for functionally unlimited questions about a city. It doesn't lie, and it's functionally omniscient for events within the city. A rather rare class from a rather rare book, it's possible that the city has kept this spell hushed up.
  • Divination, of course, runs at the same error rate as Identify Transgressor. But having a panel of diviners on hand is simply common sense of any settlement that expects to deal with mid to high level adventurers.

Almost all of these spells can be foiled due to DM intervention (A god says "no") or high-level spellcasting. At the end of the day, there's no such thing as a long drawn out trial, since there are so many ways of asking "did you do it?" from the magical spirits/ether/gods/person. Functionally, this question resolves on the tropes chosen in game and the resources the DM is willing to grant the enemy. In a high-magic, all splatbooks game, crime only functions due to the corruption of officials. With the right splatbooks restricted, it becomes far more difficult to gather evidence. With magic restricted, it becomes much harder to ask "did you do it?"

From a criminal's perspective, it's very hard to keep these capabilities secret from either a Gather Information check or a Knowledge (Local) check. None of the things above really lend themselves to NSA style obfuscation, and given that successful criminals survive to pass their knowledge on, the Lamarckian evolution that therefore occurs makes this knowledge easy to pass on. In any world where the rules are given more than lip service by the NPCs, DC 20 knowledge (local), knowledge (history) (always handy to have a bent scholar around), or gather information "How did the coppers find Joe?" as well as the belief in the deterrent effect of punishments makes methodological hiding basically impossible, save for the very greenest of thieves. Therefore, the criminal knowledge of methods will operate much like it does in our world. Most criminals will have a working knowledge of the system that they're opposing. Good criminals will have better knowledge, and the rookies will die/get caught before they gain that knowledge. Given that you have a community of thieves ferreting this information out, all they have to do is beat the DC by 5 every time to get actual details of the method.

But, at the end of the day, investigations are a function of the adventure requirements. If they happen too often, consider playing in a different system.

  • \$\begingroup\$ Kind of surprised you didn't mention Commune, since it's like some of the other divinations only more error proof. Once you get that and Find The Path, investigations tend to end real fast. \$\endgroup\$
    – Tridus
    Mar 9, 2014 at 12:44
  • \$\begingroup\$ As a consequence of the game features described in this answer, one way to make 'mundane investigation' techniques work is to make any kind of supernatural element sufficiently rare or unknown that it can be ruled out - but that only works in campaign settings where magic is already acknowledged as being rare. \$\endgroup\$
    – GMJoe
    Mar 29, 2014 at 23:38

While the answer Brian gave is amazing, it does not include any of the already present solutions. Here some classes that you should take a look at:


The vigilante combines magical and mundane investigative techniques to assess a crime scene.

Points of Interest:

Quick Search (Ex): Starting at 3rd level, a vigilante can search a 5-foot-by-5-foot area or a volume of goods 5 feet on a side as a move action, rather than as a full-round action.

Speak with Dead (Sp): Starting at 4th level, a vigilante can use speak with dead once per day. His caster level equals his class level.


A bloodhound tracks down wrongdoers and brings them to whatever justice awaits them. Low-level bloodhounds depend on their keen senses and careful training to hunt their targets. As they gain experience, their obsessive determination gives them supernatural abilities that make them nearly unstoppable.

Though some bloodhounds leave calling cards or even brands on their targets, most don’t kill their quarry if they can help it. They prefer instead to subdue their targets and bring them in. For those of good alignment, this practice satisfies some deeply held belief in the cause of justice. For neutral and evil bloodhounds, it ensures a steady stream of income from catching the same targets over and over when they break out of jail.

Points of Interest:

Track the Trackless (Su): Starting at 5th level, a bloodhound can track a creature moving under the influence of pass without trace or a similar effect, though he takes a —20 penalty on his Survival checks when doing so.

Locate Creature (Sp): Once per day, a bloodhound of 7th level or higher can produce an effect identical to that of a locate creature spell with a caster level equal to the bloodhound's character level.

Watch Detective

The watch detective specializes in solving mysteries.

Points of Interest:

Profile (Ex): Also at 2nd level, the watch detective may compose an image of someone accused of a crime. By making a successful Gather Information check (DC 15) when talking with a witness to a crime, the watch detective can gain a roughly accurate mental picture of the perpetrator, even if the witness did not see him or her. The character may, if desired, try to commit this image to paper using the Craft (painting) skill. Either a verbal or a visual depiction grants a +2 insight bonus on any further Gather Information checks made when dealing with witnesses to that crime or persons acquainted with the perpetrator.

Deductive Augury (Sp): The watch detective may ask for a hint to a mystery, puzzle, or trap. As a standard action, the player makes an assertion that can be true or untrue (such as "The half-orc did it" or "If I pull the red lever, the door will open"). The DM makes a secret percentile roll (chance of success = 70% + 1% per watch inspector level), if the roll is successful, the Dungeon Master gives the player a correct "true" or "untrue" answer to the assertion, though no reason need be given for why the response is correct. If the roll fails, the DM provides no information. The Dungeon Master is always free to determine that the watch detective doesn't have enough information to make an educated guess, but in this case the attempt doesn't count against the allowed uses per day of the ability. The watch detective can use this ability once per day at 4th level. Thereafter, he gains one extra use per day for every three additional watch detective levels gained.

Locate Object (Sp): At 6th level, the watch detective can produce an effect identical to that of a locate object spell cast by a sorcerer of his watch detective level.

Forensics (Su): With a successful Search check (DC 20), an 8th-level or higher watch detective can discern the cause of death of any corpse he examines. Given time, he may take 20 on this roll. Success indicates that he knows what killed the person, the size and approximate strength of any attacker responsible, and any other key information the DM wishes to impart.

Discern lies (Sp): At 9th level, the watch detective can produce an effect identical to that of a discern lies spell cast by a sorcerer of his watch detective level. This ability is usable once per day.

Locate Creature (Sp): At 9th level, the watch detective can produce an effect identical to that of a locate creature spell cast by a sorcerer of his watch detective level. This ability is usable once per day.

Deneith Warden

The Deneith warden is devoted, body and soul, to the apprehension of lawbreakers wherever they are found.

Points of Interest:

Devoted Lawkeeper (Ex): From 3rd level on, you gain an edge against those you know have broken the law. This grants you a +2 bonus on Bluff, Listen, Sense Motive, Spot, and Survival checks when using these skills against known criminals, as well as a +2 bonus on weapon damage rolls against such characters.

Lie Detector (Ex): At 8th level, you can take 10 on any Sense Motive check, even if threatened or distracted.

Urban Ranger

A variant ranger who stalks the treacherous streets of the city.

Point of Interest:

Urban Tracking: An urban ranger does not gain the Track feat at 1st level. Instead, he gains the Urban Tracking feat, which allows him to use Gather Information to track down a missing person, suspect, or other individual within a community.


In addition to Brian's fairly thorough answer, the right combination of tracking and Knowledge skills are quite useful. That is to say, knowing how to follow anything from its scene and having, say, Knowledge: Arcane to see where residual spell components are left or Knowledge: Nature for knowing if the marks let behind follow any natural creature (especially for the area). Essentially research is your best tool. You don't have to know the entire world, just who is in town and what creatures naturally occur. Depending on your world, population centers don't really change that much. The areas surrounding them also shouldn't be an ever amorphous blob of terrain and creatures. Thus, you can equip your +1 Vorpal Occam's Razor and strip the crime down to the useful bits.

Where things fall off the rails a bit (especially in a feudal setting) is that higher level characters/creatures tend to be more above the law because even as individuals they becomes harder and harder to take down for an arrest, more so when they start accumulating land and can pretty much consider themselves their own sovereign state and you're more likely to incite a civil war than a policing action. Sense of entitlement can also lead to a larger "footprint" in the local area and a far more distinct modus operandi whether humanoid, critter or monster.


Unless you have a very high-magic setting, most people should have very little knowledge of specific spells and spell-like effects. Average intelligence/wisdom/charisma score is 10, so most people are not able to cast any spells (0-level are not really spells) even if they'd like to become wizards, sorcerer or clerics. There may be some general understanding that wizards "can read minds", or that clerics can ask their deities to make someone speak the truth, but most people are not able to comprehend the workings of magic. The same goes for monsters, most will be rare in a typical setting and people's knowledge will be incomplete and very often misleading.

Also, consider how the society is organized. If it's a magocracy/theocracy common tasks (like criminal investigations) will be adjudicated with magic, while for a merchant republic/ feudal kingdom it might be different. "Who is this wizard to tell me, [Great Noble's Son/ Wealthy Merchant's Daughter], that I lied?" Oaths, witnesses and juries (of peers) may be of importance there. I doubt people with power would allow official use of truth-seeking magic.

For the skills, Gather Information is easily countered with time pressure (what if players don't have 1d4+1 hours?) and its description is so vague, resulting information may be unclear or plain wrong. Knowledge local is not that useful to investigate current events. While you may know (with a successful check) which investigative or criminal methods are popular, even small differences (whether planned by the perps or random) can make the knowledge-based assumptions way off.

Answers to divinations are cryptic, so it's just another source of hints for the players. Also, it's unlikely a god will allow divinations in mundane criminal investigations, how many times should a deity answer some basic questions?

Disclaimer: it's all completely different for high level characters. But they don't do simple police work, do they?


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