Investigators employ a combination of methods to determine whether a suspect, witness, or victim is telling the truth. Initially, they speak casually with the subject, perhaps under the guise of clarifying a report; this is an application of Detect Lies (p. B187). If they want to probe further, they call in the contact for an interview, which often includes carefully choreographed and rehearsed actions in an environment designed to compel the interviewee to tell the truth – a use of Interrogation (p. B202). “Lie detectors” are typically the last resort.

In 1908, Dr. James Mackenzie, a London cardiologist, invented the polygraph – so named because it monitored multiple physiological processes and graphed them. Polygraphs developed since the 1930s track heart rate, respiration, blood pressure, and skin conductivity, and display the values on a paper graph or (at TL8) a digital display. These readings indicate the subject’s degree of relaxation. In theory, since the act of lying causes tension, this means the machine can help spot a deception. The device doesn’t decide that a lie has been told, though; the operator does this, by carefully interpreting the data.

Psychologists have debated the polygraph’s accuracy since its invention. The premise that lying causes stress might not be true. In many circumstances, speaking the truth causes more discomfort than telling a lie. Certain pathological liars have no compunctions about spouting falsehoods. Furthermore, people have devised many methods for throwing off a lie detector’s calibration, ranging from relaxation techniques to stepping on a tack hidden in the shoe. The value of such tricks is itself debatable.

This controversy is also visible in practice. Some institutions, including British military intelligence and most courts of law, place no value on polygraph results. Others – notably, nearly all Federal agencies in the U.S. – routinely use polygraphs in security checks.

If the GM decides that these devices work as advertised, then a polygraph gives a modifier to Interrogation. Roll a Quick Contest between the operator’s Electronics Operation (Medical) skill and the subject’s Will. The interrogators get a bonus or a penalty to Interrogation equal to their margin of victory or loss. The polygraph operator and questioner need not be the same person; a technician with Electronics Operation and an interviewer with Interrogation can work as a team. The GM should make all of these rolls in secret.

People with the Compulsive Lying disadvantage always appear to be telling the truth on polygraph tests. The interrogators automatically have -5 on machine-aided Interrogation rolls! For appearance’s sake, though, the GM should make all the usual rolls.

If the interrogators wish, they may make two Interrogation rolls per question: one with the polygraph’s aid and one without. They have only their intuition (and possibly Intuition) with which to choose the more accurate result, however.

Polygraph (TL6). A suitcase-sized device with rubber tubing for the arm and chest, and coils of wire leading to a skullcap. $8,000, 25 lbs., external power. LC4.

Polygraph (TL8). A small box plugged into a laptop running Complexity 3 software. The subject wears a clip on his finger, a blood-pressure cuff on his arm, and a band across his midriff. $1,500, 1 lb., S/8 hrs. LC4.

The U.S. Army began researching the possibility of remote lie detectors in the 1960s. In 1970, three retired Army officers formed Dektor Counterintelligence and Security and marketed a new lie-detection system called the Psychological Stress Evaluator. This “voice stress analyzer” (VSA) could supposedly detect a liar by the “microtremors” in his voice. In 1988, a software-based computerized voice stress analyzer (CVSA) came on the market. With a VSA, nothing is attached to the subject’s body. It can be used without his knowledge and even applied to a high-quality recording. Its effectiveness and scientific validity are hotly contested, however – especially by proponents of the polygraph. For game purposes, treat a VSA as a polygraph that has half the usual effect on Interrogation.

VSA (TL7). A briefcase unit with a cassette tape recorder and a tape-strip analyzer. $25,000, 15 lbs., external power. LC4.

CVSA Software (TL8). Professional software that typically runs on a laptop. Requires a microphone (p. 41) and/or a tape recorder (p. 41). Complexity 4. $5,000. LC4.

Lie detectors help determine whether the subject believes he is telling the truth. It’s up to the investigator to decide if that subject is correct, or if he has a faulty memory, is delusional, or was brainwashed. Within these limits, ultra-tech gear using advanced neurotech is much more reliable than the polygraphs used at lower TLs.

This computer program monitors a person’s facial expression, especially facial movements near the eye muscles; different programs are needed for nonhumans. Creating software for other races requires knowledge of the race’s biology and psychology. The software uses passive visual sensors, and has Detect Lies-12. Complexity 4. LC3.

A veridicator program provides highly accurate lie detection by monitoring brain waves transmitted through a braintap neural interface (p. 215). It gives a human or computer a bonus of +TL/2 to Detect Lies skill. Neural veridicator helmets are completely reliable, providing an automatic success on a Detect Lies roll. However, people can forget, delude themselves, be fooled, or have their memories altered by brainwashing technology. A veridicator does not provide absolute truth; it just tells if someone believes they are telling the truth.

Veridicator Helmet (TL10): This incorporates a dedicated neural interface and veridicator software. The user wears the helmet; a light goes on or a buzzer sounds if he’s lying. $12,000, 2 lbs., B/24 hr. LC3.

Veridicator Program (TL10): Complexity 6. LC3.