GURPS 4 House Rules
Section 7 - Skills

HR7.1 Reaction Modifiers - B494

Reaction modifiers are no longer confined to Reaction Rolls and Influence Rolls, which are only concerned with an NPC's first impression. They also modify any use of the following skills, unless the roll is not Cha based.

• Captivate
• Carousing
• Diplomacy
• Enthrallment
• Fast-Talk
• Fortune-Telling
• Leadership
• Musical Influence
• Panhandling
• Performance
• Persuade
• Politics
• Public Speaking
• Savior-Faire
• Sex Appeal
• Streetwise
• Suggest
• Sway Emotions

Note that this is the list of Charisma based skills except Acting, Animal Handling, Falconry, Interrogation and Intimidation. Also, traits that grant reaction modifiers typically cost ±10 points per ±1 level.

HR7.2 Tech-Level Modifiers - B168

Other Technological Skills

TL penalties do not apply to aiming and firing weapons but do for maintenance.

Equipment vs. Equipment

Technological equipment that can defeat or oppose other technology, such as locks or radio jammers, are inherently more sophisticated than equipment from earlier TLs. For instance, a TL8 radio would use error correction protocols to overcome a TL6 radio jammer. At the GM's option, he can use these rules for equipment that utilize simple, brute force instead of the rules that normally apply. For instance, instead of calculating the damage of explosives and DR/HP of doors, a TL8 explosive can be considered more powerful than the TL6 explosives considered by the designers of a TL6 blast door.

For Success Rolls (B343) and Contests (B348), when using technological equipment against resisting equipment of superior TL, use Tech-Level Modifiers (B168) and your equipment TL against the resisting equipment TL to find the skill penalty.  When using superior technological equipment, compare your equipment TL against the resisting equipment TL but use the penalty as a bonus.  For instance, a TL8 burgler trying to open a TL6 lock with TL8 lockpicks has a +3 bonus. For Contests, apply any penalties to the skill using inferior equipment TL and any bonuses to the skill using superior equipment TL. These adjusments reduce to ±1 per TL difference where the application is brute force rather than sophistication, such as explosives.

This combines with any penalties for using tools of a different TL, as described above. A TL10 alien spy trying to send a signal on an TL9 radio opposed by a native agent with a TL8 radio jammer applies a -1 penalty for using archaic equipment (relative to him) but the opposing agent suffers a -5 penalty for inferior equipment (relative to the opposing equipment).

Technology Maturation

Advances in technology requires learning new concepts and techniques but the GM may deem that a specific technology is mature and commonly used in a range of TLs, or that it is improved slightly but is operated in fundamentally the same way. In such cases, when determining tech-level modifiers, equipment TL counts as the level nearest to the player's skill TL within its TL maturation range. Familiarity penalties (B169) apply as normal.

Example: Kayaks have improved since the Bronze Age but they're still someone sitting in a small boat, sealed at the waist, with a double-ended paddle. A TL1 and a TL8 Eskimo could paddle a TL6 kayak as if it were Boating (Unpowered)/TL1 and Boating (Unpowered)/TL8 respectively and only suffer familiarity penalties. They would still suffer TL penalties using Mechanic (Unpowered Boat)/TL1 or Mechanic (Unpowered Boat)/TL8 as it uses TL6 materials and construction techniques.

Example: Martian radio technology has not progressed beyond TL8 digital signal processing. Charles Schuler using Electronics Operation (Comm)/TL7 to try to tune in and record a Martian, TL9 radio conversation can treat it as TL8.

HR7.3 Optional Rule: Skill Amalgamations

The GURPS skill list is detailed but, depending on the campaign, lends unwanted emphasis to unimportant (but not banned) categories or leads to excessive numbers of specialisations. Though this is realistic, various character concepts can be too expensive or only marginally useful in the campaign.

One solution is "skill amalgamations" or "plus skills": skills that replace a set of related skills. This simplifies and reduces the cost of skills deemed only marginally useful in the campaign. Plus skills are treated as normal skills in all respects except their names end in a plus sign, such as "Physical Sciences+". If a plus skill is used, it is used instead of its replaced skills in the campaign. If a plus skill has a mandatory specialisation, it replaces all its listed skills that can have the same or similar specialisations. For example, Humanities+ (Mars) includes History (Mars) and Theology (Martian) whilst Law+ (Mars) includes Law (Mars Criminal) and Law (Mars Contract). Replaced skill names (including any mandatory specialisation (B169)), can be optional specialisations of the plus skill. For example, Hacking+/TL (Electronic Operations Security) is an optional specialisation of Hacking+/TL.

Skill amalgamations use the most common controlling attribute and average difficulty of its included skills, though this not a hard-and-fast rule. The GM decides which categories of skill amalgamations apply in the campaign.

Blinded by Science

In campaigns not focused on exploration or invention, science and engineering skills are less important. Criminology/TL and Forensics/TL are not shown as they fall into the mystery and investigation genres. Weird Science does not fit into any amalgamation and a GM should consider trait importance (HR1.5). If Computer Programming, any Bioengineering specialisation or Engineer specialisation are esoteric practices, rather than useful applications, they should be moved to Mathematics+, Life Sciences+ and Physical Sciences+ respectively.

Enough Talk

In heavily action-oriented campaigns with little roleplaying with NPCs, the talking skills can be amalgamated.

Globetrotting

In a campaign involving travel to numerous nations, such as a space opera, the number of regional specialisations can be huge. If nations share religions or cultures, remove Theology or Literature from Culture+ as appropriate. Naturalist and Survival+ applies to multi-planet campaigns and should be ignored for single planet campaigns.

Gun Fight

Where guns or beam weapons are the standard weapons, diversity of ancient weapons is excessive.

Lacks Subtly

In campaigns without much theft, intrigue or conspiracy, subterfuge and counter-subterfuge skills are expensive. As such direct campaigns tend to lack NPC roleplaying, the GM should also consider the Enough Talk option.

Non-violence

In campaigns where outbreaks of violence are rare, weapon skills can be simplified. This amalgamates the plus skills of Gun Fight and Personal Weapons.

Personal Weapons

In non-military campaigns, PCs rarely get hold of heavy weaponry.

Reliable Machines

If the GM eliminates most malfunctions for the sake of the plot, repair skills aren't cost effective. Machinist does not fit into any amalgamation and a GM should consider trait importance (HR1.5).

Urban

In mostly urban campaigns

Well Supplied

Where PCs have plenty of food and equipment, especially if they have vehicles, living off the land isn't very useful. If a multi-planet, Globetrotting option is in effect, use the Survival+ skills here instead.

HR7.4 Charisma Based Skills

The following skills use Cha as their controlling attribute and in any default, rather than IQ or Will.

• Acting
• Animal Handling
• Captivate
• Carousing
• Diplomacy
• Enthrallment
• Falconry
• Fast-Talk
• Fortune-Telling
• Interrogation
• Intimidation
• Leadership
• Musical Influence
• Panhandling
• Performance
• Persuade
• Politics
• Public Speaking
• Savior-Faire
• Sex Appeal
• Streetwise
• Suggest
• Sway Emotions

HR7.5 Autohypnosis - B176

A successful skill roll also allows the following.

Improve Defense/Piloting. Add +1 to one active defense of your choice (Dodge, Parry or Block) or +2 to Driving, Piloting or other vehicle skill (which increases Vehicular Dodge by +1). You may not talk, attack or any other action except defense and movement. This can stack with All-Out Defense (which you probably want to do). Like All-Out Defense, you may only move half if Dodge is chosen and only a step if Parry or Block is chosen.

HR7.6 Beam Weapons/TL† - B179

You must specialise by firing technology, such as chemical laser, microwave or force beam, and aiming/firing method.  The aiming methods are shown below.

Launcher: Any man-portable, shoulder-fired weapon, aimed like a recoilless rifle or RPG.

Light Automatic: Any small arm, whether one or two-handed, fired at a RoF (B270) of 4 or more.

Longarm: Any longarm, aimed like a rifle, fired at a RoF (B270) of 3 or less.

Heavy Automatic: Any man-portable, hip or bipod-fired weapon, aimed like a mini-gun, fired at a RoF (B270) of 4 or more.

Pistol: Any one-handed small arm, fired at a RoF (B270) of 3 or less.

Projector: Any weapon that emits an area effect cone or field.

Some weapons allow multiple aiming/firing methods, particularly between manual and automatic firing, and the skill for the attack rolls depends on the aiming/firing method used at the time.

Skill rolls for aiming and attacking may default to another Beam Weapon speciality, or Guns speciality at -2, with the same aiming/firing method.  Other skills rolls, such as unjamming or maintenance, may default to another speciality with the same firing technology.  Otherwise, they default to each other at -4. 

HR7.7 Computer Programming/TL - B184

The default is Mathematics (Computer Science)-5, or IQ-6 at TL9+

HR7.8 Dancing - B187

Appearance modifiers (HR2.2) are applied.

HR7.9 Diplomacy - B187

Diplomacy can produce a worse result than an ordinary reaction roll in very unusual circumstances. People aren't normally offended by an offer made in good faith but a proud person might be offended by a very poor offer or a paranoid guard might arrest you if he thinks his superiors will notice and question bribe attempts.

HR7.10 Forgery/TL - B196

Using a forgery requires a Quick Contest between the forger's Forgery skill versus the inspector's Per or Per-based Forgery. Also, once someone is fooled, no additional rolls are needed unless he subsequently has reason to suspect the document is a fake.

HR7.11 Guns/TL† - B198

You must specialise by firing technology (not warhead technology), such as slugthrower, shotgun or gyroc, and aiming/firing method.  The aiming methods are shown below.

Grenade Launcher: Any grenade launcher.

Launcher: Any man-portable, shoulder-fired weapon, aimed like a recoilless rifle or RPG.

Light Automatic: Any small arm, whether one or two-handed, fired at a RoF (B270) of 4 or more.

Longarm: Any longarm, aimed like a rifle, fired at a RoF (B270) of 3 or less.

Heavy Automatic: Any man-portable, hip or bipod-fired weapon, aimed like a mini-gun, fired at a RoF (B270) of 4 or more.

Pistol: Any one-handed small arm, fired at a RoF (B270) of 3 or less.

Some weapons allow multiple aiming/firing methods, particularly between manual and automatic firing, and the skill for the attack rolls depends on the aiming/firing method used at the time.

Speciality names can be simplified for aesthetic reasons, such as skipping the terms Slugthrower or Longarm, or renaming Longarm to Rifle.  For example, the Rifle speciality can mean Slugthrower Longarm and Shotgun mean Shotgun Longarm.  Also, Grenade Launcher is both the grenade firing technology and the grenade aiming method.

Skill rolls for aiming and attacking may default to another Guns speciality, or Beam Weapon speciality at -2, with the same aiming/firing method.  Other skills rolls, such as unjamming or maintenance, may default to another speciality with the same firing technology.  Otherwise, they default to each other at -4. 

HR7.12 Literature† - B205

This is the study of a culture's books, legends, mythologies, films and how they form the basis of its attitudes, perceptions and values. It includes knowledge of important history and theology but in romanticised forms, not the correct version. It is not concerned with current fashion, politics or etiquette though it can provide insights. You must specialise by culture

HR7.13 Lockpicking/TL - B206

The default includes Electronic Operation (Security)-2 for electronic locks only.

HR7.14 Meditation - B207

A successful trance permits one of the following:

Calm Emotion. Whilst meditating, you can calm an emotion that you regard as irrational and destructive, such as an Addiction, Phobia or awe for an overwhelmingly beautiful angel. It does not apply to self-imposed, mental disadvantages as you regard them as rational. This only delays the emotion and the GM may make the effects "catch up with you" at inconvenient moments or make you fail future self-control rolls. Also, the GM may rule this as impossible with supernatural emotions, such as Dread.

Contemplate Complex Work. Midway through a complex, mental task, after conceiving a solution but before committing to it, a meditation of duration equal to the usual time for the task grants a +1 bonus to the task's skill. This only applies to skills that require extensive information gathering, planning or invention such as Engineer, Musical Composition or Writing. Also, this can retroactively apply after a failed roll of other, complex, mental skills where the GM deems a new solution can save a failed situation, such as repairing a broken engine or solving a chess puzzle. This represents contemplating alternative solutions and checking for misapplied techniques. This does not require a deep trance and can be interspersed with simple, non-stressful activity, such as eating and sleeping. This can combine with Time Spent (B346) and skilled meditators can usually save time when being careful with their work. For example, an inventor building a prototype that would normally take 8 hours can spend 16 hours to get +1 to Engineer for time spent and try to meditate for another 8 hours midway through for another +1.

Mind over Body. After 2 hours, you reduce your stress levels and gain +1 to HT rolls to resist disease or poison. You also reduce your pain levels (B428): eliminate Moderate Pain, reduce Severe Pain to Moderate Pain and Terrible Pain to Severe Pain. This works using the Placebo Effect and does not combine with similar benefits from any kind of medicine (that you believe works), which already uses it. This effect lasts for a day after the trance.

Resolve Moral Dilemma. After 2d hours, you "feel" what is the right course of action, according to your moral philosophy system, for a particular moral dilemma. The GM may decide to make a Theology or Philosophy roll on your behalf to really get the correct answer, that your deity actually transmits the answer or that you're simply deluding yourself.

Slow Metabolism. Whilst meditating, you relax your body and slow your metabolism. You cannot move nor do anything complex or stressful. You consume food, water and air at half the normal rate. More usefully, the reduced stress aids against trauma: HT rolls for Bleeding (if used, B420), lingering through a mortal wound (B423) or Natural Recovery (B424) are at +2.

Having the skill is also a good excuse for buying off mental disadvantages (B291).

HR7.15 Performance - B212

Appearance (HR1.1) and Cultural (B23) modifiers apply.

HR7.16 Piloting/TL† - B214

Flight Pack: Also defaults to Jump Jet-2.

High-Performance Spacecraft: Does not apply to space vehicles that qualify as Ultrahigh-Performance Spacecraft. Also defaults to Ultrahigh-Performance Spacecraft-2.

Jump Jet: Any 'strap on' craft, usually a rocket-based backpack, that grants large jumps, not flight. Defaults: Flight Pack-2, Vertol-4 or other Piloting at -5.

Low-Performance Spacecraft: Also defaults to Ultrahigh-Performance Spacecraft-4.

Ultrahigh-Performance Spacecraft: Any space vehicle capable of acceleration of 1G or more and high G maneuverability. Defaults: Aerospace-4, Low-Performance Spacecraft-4, High-Performance Airplane-6, High-Performance Spacecraft-2.

HR7.17 Public Speaking - B216

Appearance modifiers (HR2.2) also apply.

HR7.18 Tactics† - B224

Ground tactics are taught by special police units as well as by the military. You must specialize by a type of combat, such as Land, Naval or Space. If no speciality is written on a character sheet, it is assumed to be Land. These specialties default to one another at -4.

HR7.19 Traps/TL - B226

The default includes Electronic Operation (Security)-2 for electronic traps only.