[johndallman]

Interrogation is the IQ/A skill of questioning a prisoner or other unwilling subject, which defaults to IQ-5, Intimidation-3, or Psychology-4. No skills default to Interrogation, although Fortune-Telling can be used in its place, with the right subject and circumstances. The GM normally makes Interrogation rolls, which are a Quick Contest against the subject's Will for each question, with victory getting a true answer, a tie or loss no answer, and loss by more than five a believable lie. In most settings, only the police, military, prison and intelligence services, and the underworld, teach this skill. The skill dates back to GURPS 1e, and its rules haven't changed much since then.

Modifiers include penalties for the subject's loyalty to his cause, +2 for a lengthy session, of over two hours, +3 for using severe threats and +6 for coercive measures amounting to torture (this doesn't have to be physical force: threats against loved ones, or use of something the subject has a phobia about, also work). Torture is also often considered vile conduct, and likely to attract punishment or retribution. Like all applied psychology, it's a complicated subject.

Interrogation isn't listed as a skill penalised by lack of Cultural Familiarity or comprehension of the subject's language, but cases could be made for both of those. Mind Probe is more useful if you have Interrogation at better than IQ level. Callous boosts Interrogation, if you use threats or torture, and Low Empathy penalises it. Extreme Fanaticism helps you resist the skill, as does anything that boosts Will.

Interrogation is common on templates for spies, counterspies, police and other investigators, and similar trades. Action uses uncontested Interrogation for questioning cooperative or neutral subjects efficiently, and has rules for handling an entire interrogation as a single contest, polygraphs and resisting them, "truth serums", using Intimidation (and its drawbacks), cinematic limitations of torture (they might say anything) and recovering from failures via Detect Lies. Action 4: Specialists includes action-movie journalists with Interrogation skill, and combat epidemiologists are the strangest interrogators. Banestorm's Michaelites and Lazarites include investigator-priests, and Bio-Tech's bioterrorist lens includes the skill. DF Bards and Holy Warriors use Interrogation on monsters, and Evil Clerics on anyone they can; Psis do it more subtly. Fantasy has templates for Slayers and Roman magistrates; High-Tech applies the skill to cartography, has polygraphs and voice-stress analyzers, and hints at techniques for inducing subjects to be forthcoming and truthful, but without details. Horror gives criminals, occultists and slayers the skill as an option. Madness Dossier "wetware hackers" use it along with drugs and electrodes. Locations: Hellsgate has a demon with an interesting optional specialisation, (Voluntary Interviews) and Metro of Madness has religious cultists who use the skill. Low-Tech has material on torture's place in historical legal systems, and methods of applying pain without doing much physical damage. Magic: Death Spells has coercion with threats of zombification, and Martial Arts has torture via Pressure Points. Monster Hunters makes much the same uses of this skill as Action.

Mysteries, naturally, has a lot about interrogation, but isn't terribly consistent with later 4e books. It reckons interviews of witnesses are Diplomacy, with its modifiers, and that only arrested or convicted prisoners get Interrogation, which is always somewhat coercive. It also has rules for using Influence rolls for questioning, and tables of modifiers for all of these.

Power-Ups volumes 3, 5, 6 and 7 all have examples for Interrogation. Powers has uses for the skill with mind-reading powers, as does Psionic Powers, and Psis; Reign of Steel: Will to Live has some powerful technological assistance in the form of virtual reality.

Social Engineering seems to embody the modern state of the GURPS art on Interrogation. It amplifies and explains the Basic rules, emphasises that Interrogation is only for prisoners, and provides rules for other skills to complement this one. Notably, it explains how to do good cop/bad cop correctly. Thaumatology has a very strange use for the skill: inflicting severe pain on yourself, as a sacrifice to spirits who enjoy that kind of thing. Ritual Path Magic has a ritual that makes Interrogation rolls unopposed, and Ultra-Tech has devices that boost the skill.

I tend to be sceptical about the real effectiveness of torture: it will get people to talk, but if they don't have the information you're after -- which someone who does know is likely to claim anyway -- all you can get is something they've made up. You're betting that your knowledge so far in the case is correct and if you're wrong, you're likely get onto a false trail.

Something that I've noticed in several gaming groups with characters who are part of a military structure or other large-scale conflict is that characters who are professional about the conflict are quite willing to apply need-to-know to themselves. They know they're at risk of capture and interrogation, and therefore make sure they don't know where the McGuffin is hidden, or who the secret heir is.

What have you got out of prisoners, or kept from your captors?