Investigative House Rules

Investigative Abilities and Skills

• Breaking and Entering: While these skills--Electronic Operation/TL (Security), Explosives/TL (Demolitions), Forced Entry, Lockpicking/TL, Traps/TL--are usually associated with the criminal element, Security officers also make use of them. Any confusion based on the fact that there is significant overlap in the use of these skills is cleared up. E.g. both Electronic Operations/TL (Security) and Lockpicking/TL can be used to open electronic locks/safes and both Electronic Operations/TL (Security) and Traps/TL can be used to disarm electronic traps.
• Criminology/TL vs Forensics/TL: Of interest to Security officers, confusion on which of Criminology vs Forensics skill is more appropriate is addressed.
• Detect Lies Skill: Of interest especially to Security officers and Counselors, Detect Lies only works by correctly observing and interpreting unintended visual and auditory clues given off by the suspected liar; it works in both formal and casual situations.
• Information Rolls: This house rule allows the PCs to make their own rolls for information.
• Interrogation Skill: Of interest especially to Security officers and Counselors, Interrogation is used to get somebody to talk about something they’d rather not; it works in both formal and casual situation, but confers no lie detecting ability.
• Stealth Skill: Know exactly how close you can approach without being detected.

Breaking and Entering

So, if you're a criminal/private investigator/spy, when would you use Lockpicking/TL10 or Traps/TL10, and when would you use Electronis Operation(Security)/TL10?--"Traps & Lockpicking vs. Electronics Operation: Security" forums.sjgames.com

The great Kromm clarified matters by informing the grateful masses that the following skills--Electronic Operation/TL (Security), Lockpicking/TL, Traps/TL--work as follows. Note the overlaps.

Two other skills merit mention for commandos, spies, and thieves.

Criminology/TL vs Forensics/TL

[Forensics is] the skill of physical clue-finding and clue analysis. Criminology is more about profiling and outthinking crooks.--"Examples of Criminology use?" forums.sjgames.com

There rules elaborate on those published in official sources.

Criminology/TL

IQ/Average

IQ-5 or Psychology-4

GURPS Action 2 Makes to following recommendations:

• Doing "generic detective work" when the GM is stuck for what skill to use (p. 10)
• Predicting criminal behavior well enough to expose clues (p. 12)
• Outthinking crooks sufficiently well to plan a police sting operation (p. 17)

Forensics/TL

IQ/Hard

IQ-6 or Criminology-4

• Physical clue finding and clue analysis.

Detect Lies Skill

Deception detection uses questioning techniques in conjunction with technologies to monitor a range of physiological functions.--"Detecting Deception". Parliamentary Office of Science and Technology (UK). POSTNOTE Number 375 May 2011.

This house rule allows users of Detect Lies to make their own rolls, which some players enjoy. This house rule also includes information on using lie detection equipment. If you consider Detect Lies to be a cinematic skill, this house rule renders it less so. (If you like this house rule, you might also be interested in the Interrogation house rule.)

Detect Lie

Per/Hard

Perception-6, Body Language-4, Psychology-4

This is the ability to determine if somebody is lying by observing and interpreting physiological changes and psychological mannerisms.

Detect Lies vs Acting

A successful Detect Lies roll means you noticed a tell that indicates the person lied or told the truth. The potential liar, however, can defend using Acting (but not Fast-Talk). If the liar makes his roll by more than you made your Detect Lies roll, the GM will give you an answer that favors the liar--the liar hides his tells or sends you false ones. An unsuccessful Detect Lies roll means you did not pick up any tells or they’re inconsistent. A critical success indicates you’ve discovered a reliable tell and will be at a +3 on all further attempts to read this individual (until they realize they have the tell). A critical failure means that person is particularly hard for you to read and you don’t trust yourself to reliably interpret their tells for the rest of that encounter. of this game mechanic, PCs should be allowed to make their own Detect Lies rolls. WARNING: Under this house rule, a career liar will often fool you.

The above table assumes the actor is lying. If he happens to be telling the truth, then this is what you will think any time your Detect Lies roll succeeds. An exception would be if the Actor wants trick you into thinking he’s lying when he’s really telling the truth. This is especially hard to do and would merit a -5 penalty to Acting skill. In any case, if you succeed in your Detect Lies roll, there are four possible results:

Attempting to Detect Lies accurately requires you to get a feel for the mannerisms of a particular subject; this takes about 30 minutes for a total stranger. For a first-time subject that you've just met, start with a -5 penalty. Reduce the penalty by 1 for every 5 minutes of quality time you’ve spend carefully observing the subject: determining if he’s right or left handed (i.e. left or right brained), establishing a baseline response by observing him answer a few questions honestly and dishonestly, etc. Taking extra time does not provide any bonuses.

A liar needs a minute to prepare or they can be caught off guard [B p346]. Apply a -5 penalty if they’ve had zero time to prepare, -10 if they’re caught red handed. Give them up to a +5 bonus if they’ve had 30 minutes or more to “get their story straight”.

Electronic Operations (Medical) vs Body Control

Detecting lies with lie detection equipment requires having the Electronic Operations (Medical) skill. Lie detection equipment becomes available at TL 6 and gives a bonus to Detect Lies skill equal to your margin of success with Electronic Operations (Medical) skill, up to a maximum of TL/2. The person lying can resist with Body Control by regulating the normally involuntary physiological changes that occur when they lie. This is a regular contest, Electronics Operations (Medical) vs. Body Control. Additionally, people without Body Control skill may be able to “get into character” enough that they, for all intents and purposes, adopt a new personality that is consistent with their lie. This is difficult and amounts to a -5 penalty to Acting skill and 30 minutes preparation; without time to prepare, the penalty to Acting is -10.

When using lie detection equipment, you may make one Detect Lies vs. liar roll for the entire session if you wish. I.e. you ask all your questions then go over the results of the polygraph later. If you are working alone, this is the preferred method as questioning while trying to actively interpret the lie detection equipments output would result in a -2 multitasking penalty to both your Detect Lies and Electronic Operation (Medical) skill.

Modifiers to Detect Lies Skill

• +1 for Sensitive or +3 for Empathy (p. B51)
• -3 for Low Empathy (p. B142)
• +4 if your subject is Easy to Read (p. B134)
• If the subject is of a different species, the GM may assess a penalty (p. B181)
• Up to a TL/2 bonus with lie detection equipment
• Up to a -5 if you haven’t spent at least 25 minutes establishing a baseline.
• The liar may also receive bonuses; up to +5 if they've prepared for 25 minutes or more. (This means non-Actors that are prepared roll against their IQ.)
• The liar may also receive penalties; down to -5 if totally unprepared, -10 if caught in the act

Examples

With Lie Detection Equipment
You have Detect Lies at 14 and your colleague has Electronic Operation/TL9 (Medical) at 12; the con man has Acting 16 and has had ample time to prepare his story. First, you spend 5 minutes establishing a baseline with the lie detection equipment. Your colleague's Electronic Operation/TL9 (Medical) roll is a 9 (made by 3) and the con man’s Acting-5 roll to beat the machine is a 13 (missed by 2); your side wins the contest and the lie detection equipment will give you a bonus of +3. A baseline established, you now begin to question the grifter. You roll against your Detect Lies+3; he rolls against his Acting+5. You get a +3 because of the lie detection equipment; he gets a +5 because he had time to craft his story.

Without Lie Detection Equipment
At TL5 you ask a working women in a saloon her age and want to know if she’s telling you the truth. You have Detect Lies skill at 12; she does not have Acting skill. This is a contest of your Detect Lies-5 vs her IQ-5. You take full reduced-time penalties in a situation like this. After about of half hour of conversation and observation, you could ask again (at a -2 penalty this time, for a repeated attempt). Indeed, it is difficult to know with certainty when you are being lied to by a stranger in a social situation.

Information Rolls

GM: Make a Hearing roll.
PC: [rolling dice] I make it by ... 4.
GM: [also rolling dice] Okay [pause] you don’t hear anything.

This house rule allows the PCs to make their own rolls for information, which some players like.

Instead of the GM rolling when a PC is gathering information (Vision, Hearing, Empathy, Perception, etc.), the PC makes their own role. Based on the situational modifiers (which the PC may or may not be aware of) and their margin of success, the GM will meet out appropriate information. If the PC rolls a critical failure, treat it as an ordinary failure; critical failures are handled by the GM.

Whenever a PC rolls to gather information, the GM also rolls. In some cases, this will be because the PC’s roll for information is a contest of skills; but even when it’s not, the GM will roll anyway. If the GM rolls a critical failure, then the result is a critical failure--the PC’s roll is irrelevant. (The GM will not inform the PC of this, of course). If the PC rolls a failure and the GM rolls a critical failure, the GM may want to wait to apply the critical failure--that PC owes the GM one critical failure, to be paid at some random/appropriate time in the future. If the PC rolls a critical success and the GM rolls a critical failure, consider the result a marginal success.

E.g. The GM requests that a PC with Per 12 make a Perception roll. The PC rolls: 3, 4, 6 failing by 1. In this case, the Perception rolls was not a contest of skills, so the GM rolls only to determine if the PC's roll is a critical failure. The GM rolls an 18. The GM decides to apply a critical failure on that PC’s next successful Perception roll.

Some may complain that spontaneously requesting the PC’s make Perception or similar rolls gives too much away. This is a good point. But, rolling dice behind a GM screen gives away information as well, though admittedly not as much. When this house rule is in place, a clever GM will request spontaneous roles as decoys. Doing this 1 in 5 times, or about 3 times each game session should be enough to desensitize players. (GMs should be requesting rolls like this purely to build tension anyway, even when there is nothing useful for the PCs to learn.)

Interrogation Skill

When used in the extreme, certain interrogation tactics can cause even ordinary innocent adults to confess.-- Kassin, S. M.; Appleby, S. C.; Perillo, J. T. (February 2010). "Interviewing suspects: Practice, science, and future directions". Legal and Criminological Psychology 15: 39–55. doi:10.1348/135532509X449361.

This house rule allows users of Interrogation [p. B202] to make their own rolls when using that skill. This house rule removes Interrogation’s lie detecting ability. (If you like this house rule, you might also be interested in the Detect Lies house rule.)

Interrogation

IQ/Average

IQ-5, Intimidation-3, Psychology-4

This is getting a person to talk about something through mental and psychological persuasion. E.g. threatening to pursue perjury charges, offering amnesty to turn states evidence, (your threats and offers need not be genuine) getting them to talk about something tangentially related so they slip up and reveal what you’re really after, etc. When they talk, they may or may mot be telling the truth. Interrogation Skill assumes the individual being questioned has reason to keep information from you. If getting the information is merely a matter of overcoming antisocial behavior, then a simple Influence Roll [p. B359] or Requests for Information [p. B560] can suffice.

A successful Interrogation roll gets someone to open up about a topic you’re interested in. The person being interrogated gets a chance to defend using their Will or Fast-Talk (but not Acting). If the victim makes their Will or Fast-Talk roll by more than you made your Interrogation roll, then they hold to their lie; otherwise, the truth comes out. Since you won’t know the results of their Will roll, you won’t know for sure which. (For that, use Detect Lies.) An unsuccessful Interrogation roll means the victim doesn’t talk or doesn’t reveal anything new. A critical failure means you give up or the person you're interrogating clams up.

The above table assumes the subject has useful information which he wants to keep secret. If he doesn’t know anything, then no amount of success will reveal anything new. An exception occurs when subject wants you to think you’ve coerced additional information out of him, when he wanted to talk all along--maybe to make a lie more believable or to keep up his street cred. This is especially hard to do and would merit a -5 penalty to Fast-Talk skill.

Each use of Interrogation skill requires 5 minutes and effectively answers one question.

Using Interrogation With Other Skills

Since the Interrogation Skill assumes that the subject of an Interrogation will not simply get up and leave, a good reaction might first be required to get them to stick around. In that case, various influence skills can come in handy. However, Reaction Rolls [p. B494] are no substitute for Interrogation skill during an interrogation [p. B562]; neither can Influence Rolls be so used (unless they can be used as a default for Interrogation).

Interrogation with Fast-Talk [p. B195]: Fast-Talk is generally used as an Influence Roll [p. B359] whenever you’d prefer that to a Reaction Roll [p. B494]. As such, it can not be used as a substitute for Interrogation skill during an interrogation [p. B562]. It can, however, trick someone into talking so that you can then use Interrogation Skill on them. Of course, Fast-Talk can be used as a Requests for Information [p. B560] when providing you the information poses no problems for the NPC.

Interrogation and Intimidation [p. B202]: Intimidation is generally used as an Influence Roll [p. B359] whenever you’d prefer that to a Reaction Roll [p. B494]. Interrogation defaults to Intimidation-3, so Intimidation can be used (at a -3) instead of Interrogation when appropriate. Intimidation can also be used to scare someone into staying put, so you can use then use Interrogation Skill properly.

Interrogation and Influence Rolls or Reaction Rolls for Requests for Information [p. B562]: Reaction Rolls [p. B494] can not be substituted for Interrogation skill during an interrogation [p. B562], and hence, neither can Influence Rolls.

Modifiers to Interrogation Skill

• -3 for Low Empathy (p. B142)
• +2 for a lengthy interrogation (over two hours)
• +3 if you use severe threats
• +6 if you use torture
• +1 extra for severe threats and torture if you are Callous (p. 125)
• The subject receives a +5 bonus to resist if his loyalty to his leader or cause is “Very Good” or “Excellent”

Examples

When You Also Have Detect Lies
You have Detect Lies and Interrogation; a punk kid has Fast Talk. You want to know if the juvenile delinquent stole the candy bar. Luckily, he’s in the mood to talk to strangers, so no influence rolls are necessary to keep him from avoiding your interrogation attempt. After 5 minutes of questioning, you roll against your Interrogation skill. If you succeed, you get him talking about the candy bar, but he gets a Fast Talk (or Will, if that's better) roll. If he makes his Fast Talk roll by more than you made your Interrogation roll, his conversation indicates he doesn’t know much about the stolen the candy bar; otherwise, something in his conversation indicates he does know something, e.g. inconsistencies in his story, a Freudian slip, a mention of something he’d know only if he stole the candy bar or saw it being stolen, etc. Whatever he ends up saying, you could use Detect Lies to determine his veracity (but at a -2 penalty for using two skills at once).

When You Don’t Have Detect Lies
You’re a defense lawyer with Interrogation skill. You know the witness just lied under oath and you intend to “break her under the cross’”. You roll against your Interrogation skill. If you succeed, the witness will elaborate; but, she gets a Will roll. If she makes her Will roll by more, then she persists in her internally consistent lie; otherwise, she caves in or slips up, revealing addition information. Depending on the actual rolls, she might let slip a verifiable lie or be reduced to a defeated blubbering wreck.

Stealth Skill

Stars, hide your fires; Let not light see my black and deep desires..--William Shakespeare, Macbeth.

This house rule adds a quantifiable component to how close you can sneak up on someone.

Stealth

DX/Average

DX-5 or IQ-5

Stealth vs Perception

The GM will use the result of the Quick Contest between Stealth and Perception and apply the results to the Size and Speed/Range Table [B550] to determine at what distance the stealthy person is seen and/or heard. Since the Stealthy person will know how good their roll is, they will have an informed opinion when they tell the GM how close and how quickly they intend to approach their quarry. If they chose a distance that is not too close, then they will not be detected; if they choose a distance that is too close, then they will be detected the moment they step into the range determined by the Size and Speed/ Range Table [B550]. On a tie, the quarry has noticed something (heard a twig snap, caught movement out of the corner of their eye, etc.) and can react, but will not know the source of the disturbance.

After the Stealthy person makes a roll, they must move one or more hexes towards their intended target. Assuming they were not discovered, they can then request another Quick Contest (at no penalty for a repeated attempt). Thus, a Stealthy person can break up their approach into more than one Quick Contest if that is to their liking.

Modifiers to Stealth Skill

In some cases, it's not obvious if a modifier should be applied to the Stealth roll or the Perception roll. Whatever is decided, be sure not to double dip.

• a penalty equal to your encumbrance level
• -5 to fool those with Discriminatory Smell, usually animals (unless you are downwind of them)
• darkness penalties will affect vision rolls

• +10 if they're in an enclosed structure, e.g. they're on the other side of a closed door
• +5 if they can't possibly see you, e.g. their back is to you
• +3 for many hiding places, e.g. stalking game in a forest where tree trunks will hide you
• -3 for an area void of ambient noise, e.g. inside a empty building, no a/c, no fluorescent lights, isolated from outside street noise
• -5 an area without "natural" hiding places, e.g. stalking someone down the hotel hallway
• -10 a bare area with no shadows, e.g. a clearing in the woods or an empty room

• a penalty equal to your move (i.e. -1 if you're moving 1 yard/sec, -0 if sneaking up slower than 1 yard/sec)
• +3 if you're move is 0, but you are still active, e.g. staying put but took a Ready maneuver
• +5 if you're move is 0, and you are effectively motionless and silent, e.g. staying put but took an Aim maneuver
• +10 if you're move is 0, you're completely hidden and not observing your foe, i.e. you're just plain hiding

Examples

Sentry Removal

Corporal Lee Linda wants to sneak all they way up to a guard who is guarding the door to an enemy safe-house. It is night; the guard and door are dimly illuminated but the rest of the surrounding area isn't. The guard is 5 yards from the corner of the building. Lee's Stealth is 13; the sentry's Perception is 11. Lee informs the GM he wants to use Stealth to sneak up to the guard, so situational modifiers are assessed. Since Lee will approach from the side of the building, where the guard can not possibly see him, he'll be at a +5 until he rounds the corner. Once he rounds the corner, he'll be in a bare area, a -10 penalty; but it's dark, so the GM decides a net penalty of -5 is appropriate.

Lee sets out, rolling an 11, a success by 2. Assuming the sentry made his Perception roll exactly and ignoring situational modifiers, Lee would be detected when he got 1 yard from the guard: -2 on the Size and Speed/Range Table [B550]. Applying the -5 penalty after rounding the corner results in a failure by 3. +3 on the Size and Speed/Range Table [B550] means Lee would be detected 7 yards away. Lee thinks he can do better, so he informs the GM he'll move up to the corner of the building. Lee doesn't know this, but the guard also rolled an 11. Since Lee is at a +5 until he rounds the corner, he easily makes it to the corner of the building without being heard.

Having gotten to corner, Lee now rolls to proceed even closer. He'll be at -5 after he rounds the corner. Lee rolls a 9, succeeding by 4, adjusted to failing by 1: 3 yards on the Size and Speed/Range Table [B550]. Lee knows this in not close enough to attack with his Garrote, but he is committed to moving at least one yard closer. Lee informs the GM he'll move only one yard closer this turn. (He's hoping that if he's not detected this turn, he'll be able to All Out Attack him next turn with the element of surprise.) The sentry rolls an 8, succeeding by 3; so Lee actually lost the Quick Contest by 4, resulting in detection at 10 yards. The GM informs Lee that as soon as he rounds the corner, the guard looks over and sees him. (The element of surprise diminished, Lee will be forced to choose between attempting to take him out quietly in hand-to-hand combat, or readying his M4.)

Bow Hunting

Shung Jiao and Shung Li are out bow hunting. Jiao would like to get as close as possible before taking his shot. Li is tracking the wild boar and they are both moving stealthily as the trail seems fresh. They are in the woods and the boar is not downwind of them, so the GM gives them a +3 bonus situational modifier. Shung Jiao's Stealth is 10, Li's is 12; Shung Jiao rolls a 9, Le rolls an 11; they both make their rolls by 1, by 4 with the modifier. They would like to get within 15 yards of the boar. (Shung Jiao's bow skill is 12. Acc 1 with 3 seconds of aiming can increase this to 15. The range penalty at 15 yards is -5.) If they lose the Quick Contest by 4 or less, they're okay. (5 is not okay because then they'd be detected at 15 yards.) They decide this roll is good enough that they've probably not even lost the Quick Contest and commit to approach to 5 yards. Unknown to them, the boar with Perception 12 rolled a 10, succeeding by 2. They won their Quick Contest by 2. The GM informs then they're 5 yards away from a wild boar that is ignoring them. Shung Jiao can now set up his shot.

If Shung Jiao decides he wants to move even closer (maybe Shung Jiao decides he wants to staff hunt instead) they will both have to engage in another Quick Contest. Of course, Li will be at +10 since he will choose not to approach with Shung Jiao.