My Miscellaneous Old House Rules (GURPS 3e)

Most old house rules have been absorbed into other works on this site. On this page are a few miscellaneous 3e tweaks – some much used, others tasted and soon forgotten – that didn’t fit elsewhere. (A few now have some sort of simulacrum in GURPS 4e.)

It’s all ramshackle old stuff (1997 or earlier!), but might contain something of interest for your modern GURPS game.


v1.0: 1997

v2.0: 01/08/01

v2.1: 09/10/24. Minor updates, and moved article from old HTML file to current site format.


The old 3e house rules

These rules fall under categories inspired by the time-honored motion picture rating system in the US:

G (General GURPS): It may or may not be in the main rulebooks, but it already appears somewhere as an option in GURPS, or otherwise has been endorsed by SJ Games folks.

PG (Pretty Good stuff): These rules fix something important or make a quick and easy improvement, all without straying far from “official” rules. Give this stuff a try.

R (Restricted to GURPS freaks only): I like it and you might too, but it’s not for everyone. These are rules that add nifty stuff but take a mean whack at the rules. Or they address “problems” that you’d not likely ever care about.

X (Xperimental! Xceedingly risky!): Little tested. Use at your own risk. Don’t blame me if the sky turns black, crows gather, and in the next village a pig is born with human voice.

G Rules

Changes to Advantages

Absolute Direction: Adds +3 to Orienteering and +1 to Surveying, in addition to other effects.

Will cost: The cost of Will is widely regarded as broken: for example, you get more points for IQ 10 and Weak Will -2 [-16, with Will Roll of 8] than for a straight IQ 8 [-15, also Will Roll of 8].

I use a cost of [-4].

Will terminology: The terminology surrounding Will is clumsy, what with Strong Will and Weak Will as modifiers, and these plus IQ labeled Will . . .

Call the modifiers simply “Will”: instead of “Strong Will +2” and “Weak Will -1”, say “Will +2” and “Will -1”. When this is added to IQ, call it “IQ plus Will”; when added to HT, “HT plus Will”.

This is easier to understand, and makes clear that Will is a unique entity, not a component of IQ.

New Skill Categories

The following new skill categories have been added to GURPS Compendium I, thanks to the suggestions of Yours Truly:

  • Knowledge: Area Knowledge, Bardic Lore, Rituals, Baseball Lore, etc.
  • Military: Tactics, Strategy, Intelligence Analysis, Traffic Analysis, etc.
  • Esoteric: Meditation, Breath Control, Breaking Blow, etc.

New skills

Law Enforcement (M/A, defaults to IQ-5): This skill pops up in GURPS here and there, but worldbooks often forget to suggest it for modern-day police! A cop without Law Enforcement skill is as realistic a character as an Actor without Acting, or a Lawyer without Law. This, and not Guns, is the core skill for a modern officer.

Two-way defaults with Administration (Police) at -5, and possibly with Law at -6, make sense.

PG rules

Attribute Modifiers

GURPS’ Guns skill is based on DX, but receives a small bonus from IQ. Here’s an expansion of that concept into a broader method for basing a skill on one attribute, with a bonus from a second attribute:









18-21, etc.

Attribute Modifier









Guns would use a DX base with an IQ Attribute Modifier drawn directly from the above table. A PC with IQ 12 would get a +1 to Guns; with IQ 15, a +2; etc.

Other examples that make sense:

  • DX base with IQ Attribute Modifier: Guns, Gunner, Bow and other missile weapons, most Vehicle skills.
  • IQ base with DX (or Manual DX if appropriate) Attribute Modifier: Lockpicking, Forgery, some artistic and musical instrument skills.

You could go as wild as you want, with IQ Attribute Modifiers for Singing, DX Attribute Modifiers to many Craft skills, etc. But keep it fairly simple.

Changes to Advantages/Disadvantages

Literacy: This can be treated as a skill. An illiterate person reads at IQ minus 10; raising Literacy costs one point per +1. Thus, raising it to full IQ costs the same 10 points as in GURPS. A Literacy level of 5 or so would be considered semi-literate.

Then again, satisfactory rules for multiple Literacies covering many languages and character sets still don’t seem to have appeared for GURPS.

Eidetic Memory: This should double or quadruple points for only some mental skills, and give a +1/+2 bonus per spells to other mental skills.

Suggestion: give any skill that relies on social ability, on-the-spot problem-solving, or “mystical” abilities, as opposed to recall of facts, the +1/+2 bonus. These include all Magic, Esoteric, and Psionic skills, all Social skills, and many more.

But does a PC’s “total recall” derail your adventures? The Observation skill (below) can help keep Eidetic Memory in line. 

New Skills

Magic (M/VH, plus Magery bonus. Defaults to IQ-6): See separate article on the Magic skill and its numerous options, as well as a suggestion for magical languages.

Musical Theory (M/H. Defaults to IQ-6): The skill of composition, musical theory, etc. Add 1/10 of skill level to skill with musical instruments, per Linguistics and languages.

Nunchaku (P/H. Defaults to Flail -3, and vice-versa): In a game that carefully differentiates between skills for using knives, short swords, broadswords and two-handed swords, the skills for nunchaku and two-handed war flails should not be one and the same.

Observation (M/A, defaults to IQ-5, add Alertness and Acute Vision bonuses to skill): This represents the trained, conscious skill of taking in and noticing details, a vital skill for an investigator, spy, or scout. Use it like a Vision roll to walk into a crime scene, absorb details of the surroundings while casually conversing with a suspect, and then head straight for the cigarette butt in the trash can that doesn’t match the victim’s preferred brand. (Extracting detail from a conversation is part of the Interrogation skill, not Observation.)

Observation lets the GM to hand out bits of extra information beyond what a passive Vision roll offers, and is useful in disputes over what a character saw in the past. Any PC should recall whether an intruder’s face is that of the contact the PC spoke with the night before. But in response to the question, “Is this earring I found the same as the earring my contact was wearing?”, the GM does not have to give an answer! There’s no reason to assume the PC paid attention to a detail as minor as the person’s earrings during the conversation. Make an Observation check to settle the question.

Similarly, Observation helps keep Eidetic Memory abuse under control:

Player: “Okay, we found the spy’s license plate number in the database! Now, does my Eidetic Memory recall that number on any of the cars parked in front of the lab yesterday? If so, we’ve solved the case and wrapped up an adventure in record time!”

GM: “Er, not if your character never looked at the numbers in the first place…”

Unless the player specifically said he was checking plates, there’s no reason to assume the character even glanced at them. An unsure GM can make an Observation check; success indicates that the PC did indeed cast an eye over the numbers.

A normal PC who hadn’t purposely checked the plates might have glanced anyway on a good Observation roll, but there’s no reason to expect he’d remember the numbers. An Eidetic character would recall the numbers, if an Observation roll indicates he paid attention in the first place. A level 1 Eidetic might even recall the number a year later, on an IQ roll; a Level 2 Eidetic recalls it, period.

For a more easily-remembered fact, like a face or voice, both normal PCs and Eidetic ones could recall the fact a short time later (assuming they noticed in the first place, by intent or through Observation). A year later, the normal PC would have a tough time recalling the fact (IQ roll at a penalty), the Eidetic Level 1 character wouldn’t have much trouble (IQ roll with a bonus), and the Level 2 memory machine would have automatic recall.

Changes to skills

Cyphering: The ability to perform simple arithmetic, this comes from GURPS Fantasy, and could be renamed Arithmetic.

However, as a M/E skill, improving Cyphering costs the same 2 points/level as improving Mathematics, which covers much, much more!

Change Cyphering from M/E to an “innate” skill like a native language: characters start with Cyphering at IQ, and can improve it for 1 point per level. The skill covers only simple arithmetic; Mathematics can replace any Cyphering roll.

Optionally, to reflect the fact that even arithmetic was not a common ability in past eras, subtract one from starting skill level per TL under 6. An IQ 13 character would start with Cyphering-13 at TL 6 or later, but only Cyphering-10 in a TL 3 medieval world.

Katana: Has any topic raised as much ruckus as this in online debates? In short, the weapon stats and skill description are way out of line for many gamers. Katana skill in GURPS includes not only an improved Parry but also both one-handed and two-handed use, which would cost broadsword users twice as many points to learn! And the weapon itself seems to have been imbued with mystical speed qualities.

Let’s give amazing samurai swordsmen some respect, and assume that their abilities come from training and discipline (i.e., lots of points in skills), not from a skill that happens to be unusually cheap. Split Katana into One-Handed Katana and Two-Handed Katana, defaulting to each other at -3. The primary skill for Kendo becomes Two-Handed Katana, with One-Handed Katana as a secondary or optional skill. (There’s no reason why regular Broadsword and Two-Handed Sword shouldn’t also default to each other at -3.)

This is all realistic. Kendo does not teach one-handed katana use! Yet GURPS assumes that a Kendo master, who has battled for years using nothing but two hands, can at any time switch to one hand and fight as if he’d been using nothing but one hand all those years. His Western counterpart, meanwhile, a master of the two-handed sword, switches to one hand and finds himself clumsily flailing away at default skill… Not very sensible. It’s true that one- and two-handed use were both learned by the stereotypical samurai, but that doesn’t make them one skill, any more than broadsword and shield use should be one skill for a European knight.

As for the weapons themselves, the weapons that people generally think of as katana do not seem to be 2-hex weapons, though such longer versions no doubt exist. Give katana the same stats, basic damage, readying time, etc. as equivalent broadswords and bastard swords; the only difference is that they might more often sport Fine or better quality, and that even the one-hex model can be used with two hands for additional damage.

The improved Parry for two-handed use remains reasonable; there’s no harm in assuming that even sword skills can have higher “tech levels” with improved capabilities.

That leaves Katana skill and the weapon on par with their Western counterparts, at the base level – yet it’s still perfectly possible to build superior Eastern fighting arts, if that’s your goal. Just put points into maneuvers (or that couldn’t-be-simpler standby, a high skill level!) and good stats to reflect a steely samurai’s dedicated training, give him a Fine or Very-Fine sword, and possibly add “mystical” abilities from Martial Arts: Power Blow, Weapon Master, etc. No inflated skills or funny physics necessary.

Running: Skills like this are best gamed as replacing the base attribute where appropriate (as in the (DX+HT)/4 base for Move), not as adding directly to Move (or other relevant stat).

Defaults from IQ skills to DX skills and vice-versa

When an IQ-based skill defaults to a DX-based skill, or vice-versa, replace the original attribute with the appropriate one in the default skill.

Example: Bicycling -8 allows one to repair a bicycle – i.e., Mechanic (Bicycle) defaults to Bicycling minus 8. But Bicycling is based on DX, and Mechanic skill should not benefit from athletic agility! Replace DX with IQ in the default Mechanic skill. For a character with Bicycling at DX+3, default Mechanic (Bicycle) is not DX-5, but IQ-5.

IQ-based defaults from physical skills, representing knowledge about that skill, are possible: for example, Sword Knowledge defaulting to Broadsword. With Broadsword at DX+1, the PC could roll at IQ+1 to guess a sword’s quality, properly name the maneuvers and moves used in swordfighting, etc. GURPS already allows an Armoury default at Weapon Skill minus 6; the DX+1 swordfighter should have his Armoury (broadsword) default to IQ-5, not DX-5. And so on.


Offer the following three options on an All-Out-Defense:

  1. GURPS method (double total number of defenses, and allow two defenses per attack)
  2. Normal number of defenses, and only one defense per attack, but +1 on any defense
  3. Normal number of defenses, and only one defense per attack, but +2 on one mode only (Dodge, Block or Parry), no bonus on the others.

#3 is the most useful when a fighter doesn’t have a second defense to fall back on.

R rules

Skill Specialization

I lower the skill bonus for optional specialization from +5 to +3. This still leaves a 4-point gap between the specialization and the lowered main skill, which in GURPS is a big difference. The game’s standard 6-point difference feels excessive.

X rules


The basic idea of subattributes within attributes won’t disturb die-hard GURPS hackers, who have seen (or started) many an online discussion of the same. Infinite subattributes are possible, one reason online discussions on the topic don’t go far…

A subattribute is a “smaller part” of a major attribute, and can be bought up or down separately. A good example would be “manual dexterity”, or the ability to do fine work with the hands. This is normally part of GURPS’ DX, but it’s easy to imagine unathletic characters with nimble hands, or fleet-footed, butter-fingered jocks.

Below is my favorite grouping of attributes and subatts:

ST/MAS – Strength/Mass

DX/MDX – Dexterity/Manual Dexterity

HT/FTG – Health/Fatigue

IQ/MSP – Intelligence/Mental Speed

Raising subatts: Pay 40% of the additional cost to raise the main attribute to the desired level.

Lowering subatts: Get back 20% of the additional points from lowering the main attribute to the desired level. Yes, this is a very small point bonus; no point crocks here.

What are they all?


MAS: This correlates roughly with weight, as an overall measure of bulk and mass. A Giant would have high ST and a high MAS to match; a superhero, high ST but normal MAS.

Why would one pay points to raise this? It’s valuable under the “Hit Points = ST” rule: use MAS directly as Hit Points, instead of using GURPS’ Extra Hit Points or Reduced Hit Points.

(GULLIVER for 3e note: For humans, MAS would equal body weight (minus extra weight from the Fat family of disads) / 15.)

DX: GURPS DX, for whole-body movement.

MDX: DX for purposes of hand-eye coordination. Affects skills such as Pickpocket.


FTG: HT for purposes of determining fatigue. FTG will affect how much ST a character loses from strenuous activity. A high stat would be good for fantasy Dwarves!

IQ: GURPS IQ, a savory blend of a thousand different mental capabilities.

MSP: Determines how quickly an IQ-based decision is made. Enterprising GMs can think of interesting uses for this. MSP might affect skills such as Fast-Talk, and determine reaction time in surprise situations.

If MSP, not IQ, is the score used to roll a surprise check, then it can be used as a more variable replacement for the Combat Reflexes advantage. Give the fighter an MSP of 5 or 6 above his IQ, and roll vs MSP to avoid surprise. MSP should also affect active defenses: I add +1 AD per full 5 points of MSP above 10. This makes MSP a powerful subattribute; it’s the type of quick-thinking “smarts” that a warrior needs even if his IQ is abysmal.

I didn’t include Will as a subset of IQ, as many have suggested; I don’t care for Will as part of IQ.

New Attributes

A delightfully controversial topic. As with subatts, you can devise any number of new attributes to thrill and annoy GURPS gamers.

My two fave candidates are currently incorporated into GURPS IQ. There’s nothing wrong with the way IQ includes everything and anything related to the mind: memory, will, learning ability, creativity, artistic talent, logic, intuition, social skill, spiritual or psychic strength, etc. IQ is defined as an amalgamation of all of those, and that’s a perfectly fine (and simple!) way of doing things.

But I’d like to see (in particular) social ability, will, and spiritual aspects distanced from the “memory”, “reason”, and “intellect” aspects of IQ. With that in mind, here are my potential new atts (with optional subatts):

PR/WIL Presence/Will

AW/SAW Awareness/Self-Awareness

The explanations:

PR: This is force of personality. PR replaces the Charisma advantage, and forms the base for Social skills and general reaction rolls. It’s expensive, but includes an important subatt. And social skills can be the most powerful skills of all: Broadsword can take down a troll, but Diplomacy can build or topple a nation.

WIL: GURPS Will score, made separate from IQ. It’s sensible that this be closely tied to Presence. Someone with the forcefulness to influence others will likely have the will to resist their opposition and counter-attempts at influence. Someone with an iron will and steely confidence will likely possess the presence to force that will onto others.

Presence and Will are two sides of the same coin: force of personality. Presence is outward-directed force of personality to influence others, and Will is inward-directed force of personality to resist outside influences.

AW: A new attribute to measure “spiritual” strength, replacing IQ as the base for the mystical, “chi”-based skills in Martial Arts. Awareness (for lack of a better name) is perception of the outside (including “unseen”) world, affecting “mystical” abilities such as Intuition, Empathy, and magical powers and skills. AW would be a better roll than IQ for use with abilities like Intuition.

It may also link to creativity, affecting artistic skills, and as a measure of perception, affect Sense rolls somewhat. (I haven’t experimented that far.) 

SAW: Similar to AW, but inwardly-directed; this is one’s perception of, or harmony with, the “self”. Affects powers based on “chi” or of the mind (psionics); along with AW, might even denote “enlightenment”.

I haven’t defined and developed the AW/SAW combo much, which is one reason why I’m not using them. But if I were to start a campaign heavy on magic or mysticism, I’d give these more effort. In particular, I think the combo might help in linking together the many oddball new “attributes” found in the GURPS World of Darkness books, such as Humanity, Gnosis, and Arete.

New Skill Bases

One can concoct new new bases for skills, to better represent the actual talent that aids a skill and add a bit more variety and interest to the question “what would this character be good at?”.

Instead of Craft skills falling arbitrarily into either the Mental or Physical categories, the average of IQ and (Manual) DX could form the base. This reduces the value of any one attribute in the skill, meaning super-IQ characters will not be quite as naturally gifted at potterymaking and weaving as they will be at spells and astrophysics. Modest-IQ characters will find that they can better compete with the geniuses at crafts than at advanced mathematics.

A base other than IQ is good for mystical skills like Zen Archery or Power Blow. This keeps the game’s rocket scientists from proving born adepts at controlling “chi” and divining spiritual mysteries. The average of HT and IQ-based Will models “chi” much better than IQ, in the absence of something based on AW/SAW (above).

That said, basing all skills on either DX or IQ alone does have one wonderful advantage: simplicity. And there’s already a simple method above for skills influenced by more than one attribute: attribute modifiers, similar to the IQ bonus GURPS gives Guns. Skill Bonus traits (GULLIVER for 3e; also Talents in 4e) further fine-tune characters: a PC with modest IQ, combined with a scientific ability advantage, can be an inventor genius who isn’t necessarily a natural at Diplomacy, Pottery, Pressure Secrets and Animal Handling.

While new attribute bases are an interesting idea, the above options make them probably not worth the time – and thus, an untested X rule.