GURPS House Rules

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Fourth Edition not only streamlined GURPS, it fixed a lot of rules and exceptions that were unbalanced or otherwise broken. Of course, even an unashamed fanatic like myself has to admit that a few things can still use some tweaking. All of my house rules here have been extensively playtested and have had a positive effect on the system. Click on the rule if you want to know the details, or the rationale behind it.

Many of these house rules are available in GCA Files if you want to incorporate them into your own game.

The indented section beneath each house rule is the detailed explanation; feel free to skim or skip it.

Perception and Will are separate from IQ.

Both Per and Will are their own attributes. They start at 10, and can be raised or lowered for 5 points/level. IQ is unchanged, at 20 points/level.

This is a big change, but an important one. As written, if you lower your character's Per and Will, you'll see that IQ (just IQ by itself) costs 10 points/level. Compared to the price of Talents, Magery, and even skills, that's just too little. Now that mental skills cost more per level, it's unbalancing to make IQ cost less.
In addition, it makes themetic sense for Will and Perception to be divorced from IQ. Intelligence certainly doesn't affect alertness -- look at any animal to see that. And your strength of will isn't related to how smart you are, otherwise nerds would intimidate jocks, not the other way around.
This does slightly change the cost of building characters, so you'll want to mentally add about 10-15% to the starting character points suggestions in the books.
(Note that Affliction (Attribute Penalty, IQ) no longer reduces Per and Will. Instead, the Attribute Penalty enhancement may be bought for each at +5% per level. Similarly, Steal Will and Steal Per are +100% enhancements for Leech.)

Reducing the value of "flavor" traits.

The values of all age-related traits (Extended Lifespan, Longevity, Self-Destruct, Short Lifespan) are halved, except for Unaging, which costs 5 points. Terminally Ill no longer exists, except when granted via an Affliction.

These are what I call "flavor" traits. It's neat to say that your elf is 1,500 years old, but that's about it. In all but the most unusual campaigns, the game is unlikely to go on long enough that age comes into play. And Terminally Ill is a horrible example of a disadvantage. It does nothing to inconvenience your character in any way, shape, or form, until one day when you just die and make up a new character. Adding a Mitigator is one step towards fixing the problem but a equally large step towards making it worse (since now your timetable is indefinite).
If you have a horrible disease that's going to kill you, buy appropriate disadvantages. If the only thing keeping you alive is an experimental drug, take a Dependency. If you're morose over your situation, take Chronic Depression. But you shouldn't get any points for something that doesn't affect you until it's too late. I'd call that a Quirk ("At some point, I'll be replacing this character with a new one.")
Note that Destiny is unchanged, but there should be an emphasis on ensuring the destiny comes into play before the campaign ends.

Arm DX, Arm ST, and Regrowth are cheaper.

Arm DX costs 9 or 12 points for one or two arms. Arm ST costs 3, 4, or 6 points for one, two, or three arms. Regrowth costs 10 points.

Arm DX appears to be priced in comparison to DX at 20 points per level. That is a mistake, however, as Arm DX does not affect Basic Speed and should thus be priced comparably to "just DX" (i.e., DX +1 and Basic Speed -0.25), which is 15 points per level. Otherwise, you'd be better off spending the 15 points to improve your overall DX instead of spending 16 points to only improve your two arms. The easy way to fix this is to make the price comparable to "just DX" at 15 points per level and adjust the value of Arm DX proportionately.
Arm ST has a similar problem in that it appears to be priced in comparison to ST at 10 points per level, while it really should be compared to "just ST" (ST +1 and Hit Points -1) at 8 points per level. The simple solution is to again reduce the values proportionately. Unfortunately, only "Two Arms" can be reduced evenly by 20% (to 4 points), and I'm not willing to have fractional values for a basic advantage. From experience, I can say that the utility of "One Arm" versus "Two Arms" versus "Three Arms" is about the same, really; players will always use their strongest limb(s) unless forced not to. Therefore, I rounded towards the value of "Two Arms", to err on the side of keeping their prices similar.
Regrowth is a different issue. Essentially, it gives you a weaker version of Injury Tolerance (No Eyes [5], No Vitals [5], and Unbreakable Bones [10]) -- you do take the injury, but can grow it back over a long period of time. Considering that for 20 points you can be absolutely immune to dismemberment, it makes no sense to charge 40 points to be able to recover from dismemberment over a long period of time. I think -50% is a conservative value for "Loses the limb/organ but grows it back weeks/months later", which sets a fair value at 10 points.

Control can be used normally to provide DR.

Each level of Control can be used to give people in your area of effect DR 1 versus appropriate attacks. A successful, IQ-Based Power Block will double any defensive use of Control for one attack.

Per GURPS Powers, using Control to provide DR requires a special "stunt" known as a Power Block. But to me it seems logical to make it a normal use of Control. If each level of Control can give you +1 to resist an Affliction, +1 to ignore a combat penalty, or -1 on an opponent's combat penalty (depending on the substance or energy being controlled), adding +1 DR doesn't seem very far-fetched or overpowered. And, with this rule in place, it then makes sense to allow a Power Block roll (instead of the normal IQ roll) to try to double the defensive effects of this ability.

Costs Fatigue is worth -10%/level.

Costs Fatigue is worth -10% per level, to a maximum of -40%. If you have an advantage that would normally remain on indefinitely, you can take "Costs 1 FP per 10 seconds" for -20% or "Costs 1 FP per second" for -40%.

In my years of gaming, I have noticed that abilities with no energy cost whatsoever are immensely more useful than those with even a minor cost. Take a super with a laser eye-beam. If he gets into a fight, there's no reason he can't use it 20 or 30 times in the span of a combat. Add even a 1 FP cost to it, and suddenly he can't use it more than 7-8 times without seriously imparing his ability to fight -- and that's if nothing else fatigues him (or already has)!
Note the -40% cap, however, to prevent this from becoming a free ride. Otherwise you find the munchkins buying their FP up and then adding "Costs 40 FP, -200%" to bring down the cost of their 500-point ability with a ton of enhancements. Also note that there is no "Costs 2 FP per 10 seconds" limitation. This rewrite gives a fair point break while preventing the worst instances of abuse.
Optional Complications: "Costs Hit Points" is worth 1.5 times as much -- hit points are harder to recover and more dangerous to lose. If you have any abilities that allow you to recover at least 1 FP or HP (as appropriate) per second, this limitation is worth 1/5 as much. If you can recover faster than that (e.g., Extreme Regeneration), it's worth 1/10 as much. The fact that you have to pay the energy cost is still a minor limitation, on about the same level as a Nuisance Effect.

Armor Divisor (100) is available.

Armor Divisor (100) is available as a +300% enhancement. This is a fair price in comparison to Cosmic (Irresistable Attack), which is more effective but is also stopped by Cosmic DR. Hardened DR reduces both enhancements normally.

Per recent clarification, the Cosmic (Irresistable Attack) enhancement is reduced by the Hardened enhancement exactly as if it were a higher level of Armor Divisor. In addition to that, the Cosmic enhancement on DR allows it to completely stop Cosmic attacks -- in a sense, it acts as "Hardened 6, Only Versus Cosmic Attacks".
So, the only "missing" level of Armor Divisor (looking at the Hardened enhancement) is Armor Divisor (100). It seemed fairest to make it +300%, as dividing DR by 100 is almost as good as ignoring it. It's not quite as effective as Cosmic, but it also isn't affected by Cosmic DR, which seems like an even trade.

Various new modifiers for traits.

While building characters and helping others to do so, I've come up with several new "special modifiers" for various advantages, as well as a new advantage (Indefatigable). Unlike the other house rules, this will load as a separate page -- it's too long to do inline.

Enthrallment skills require an Unusual Background.

For balance purposes, an Unusual Background is required to learn and use the four Enthrallment skills. This costs 5 points, plus 5 points for each level of Charisma (maximum 30 points.)

Even with a mere Charisma 1, the Enthrallment skills act as an easy Charm Person. Sit down with someone at a bus station, tell him the story of your life, and suddenly he's robbing the ticket window. This adds a surcharge which brings its cost inline with that of restricted Magery or limited, area effect Mind Control.
This house rule does not apply to Madness Dossier games or other games where Enthrallment is not Charisma-dependent.

Temporary Enchantment fixed.

When using the Temporary Enchantment spell (from GURPS Fantasy and Magic), multiply the energy cost of the enchantment by (Uses)/(Uses+6), rounding up. So a wand that can cast Fireball 30 times costs (30/36), or 84% of the normal energy cost to enchant.

The idea behind Temporary Enchantment is a good one, but why make it impossible (or ridiculously expensive) to make an item with a dozen or more charges? This makes a one-shot item cost the same (15%), while allowing for as many uses as you want.

Slams use the Dungeon Fantasy RPG rules

See the Dungeon Fantasy box set for details.

(Psi) Static comes in two levels.

Resistible is no longer a limitation. Instead, it is the first level of Static, with a cost of 15 points. The normal advantage, as written, is the second level.

The difference between, "You cannot use your power on him (or in this area) at all, period," and, "It's very difficult, but possible, for you to use your power," is a significant one. In my experience, complete static is easily worth twice as much as resistible static. GURPS seems to agree, at first glance. Simulating this with a -50% limitation works by itself, but when you throw a couple of enhancements on there (such as the Area Effect which is de rigeur for building a "screamer") the cost difference quickly changes to a flat 15 points.
I posit that if the ability to completely shut down every psi within 128 yards, no matter how skilled or powerful they are, is worth 150 points, then the ability to merely make it difficult for them to use their psi should be closer to 75 points than to 135 points. The way to achieve this is to change the base cost, so Static (Resistible) is 15 points and Static (Complete) is 30 points.

Changes to Trading Points for Money and Signature Gear.

The starting cash you get by trading in points now scales up (using a similar progression to Wealth) and is based on your starting wealth, not the campaigns. This makes it a fair deal for wealthy characters while reducing abuse from poor ones. Signature Gear no longer provides funds; it simply adds plot protection to gear that you've already purchased. Because there's a table involved, this house rule is located on its own page.

Streamlined Languages for Modern Games.

In games set on modern Earth, 99% of the people will speak one of the following languages: Arabic, Bantu (Southern African), Berber (Northern African), Cantonese/Wu (Chinese), Dutch/Afrikaans, English, Farsi/Kurdish (Iranian), Finnish/Hungarian, French, Gaelic/Welsh, German/Yiddish, Greek, Hebrew, Hindi-Urdu (Indian/Pakistani), Indonesian/Malay, Italian/Romanian, Japanese, Korean, Latin, Mandarin (Chinese), Navajo, Norwegian/Swedish/Danish, Polish/Czech, Russian/Ukranian, Spanish/Portugese, Thai/Burmese, Turkish/Mongol, or Vietnamese/Cambodian. A slash means that the languages are closely enough related that, for simplified game purposes, they count as a single language.

The real world has thousands of active languages, but that doesn't mean that a game should. In my experience, most players avoid investing heavily in languages (even in a globe-trotting game) because they realize that even if they learn a dozen languages, they can still only talk to a small fraction of the world.
This change attempts to fix that issue. Combining similar dialects broadens the scope of many languages. But more importantly, this rule is an agreement on the part of the GM that these languages are going to be the ones that come up in the game. This isn't a statement that (e.g.) other dialects of Chinese don't exist! It just means that if the party encounters a Chinese NPC, he will speak Cantonese, Mandarin, or Wu.
Obviously, hidden or secret languages are not on this list. Also, there may be a valid in-game reason to intentionally give an NPC a different language, but if so, that automatically becomes a plot point -- players should think, "Huh, that's interesting that he speaks Lakota -- I'll have to make a note of that," not, "Damn, that lying GM never told us that we had to learn Lakota, too!"
(And if your particular language or dialect is not on this list, sorry! It's chosen from an American point of view; no offense is intended.)

Combat, Combat Art, and Combat Sport Skills Are Techniques.

When you learn a Combat skill, Combat Art skill, or Combat Sport skill (see p. B184 for details), you may buy up the other two versions as an Average technique defaulting to your skill-3. For example, if you know Karate Art at DX+2, you know Karate at DX-1 and can buy it up to DX+2 level for 3 points.

This change is due to equal parts game-balance and realism. As the rules are written now, if you know (e.g.) Broadsword at DX+4, it costs 12 points to buy just your Broadsword Art up to the same level. That's a game balance issue because you're wasting points -- not just due to the lack of utility, but because you'd be nuts not to just spend the 12 points on Broadsword (raising Broadsword Art and Sport by +3, from default, simultaneously). While that issue comes up with other defaults, it's especially bad here, as many martial arts styles require you to, e.g., learn both Judo and Judo Art. And it's a realism issue, because fighters and athletes do transition between (e.g.) tournaments and MMA fighting without spending a full year training non-stop to adapt. A technique is a fair compromise; at 3 points per skill, it costs 6 points to raise all three variants to the same level -- exactly half of the 12 points mentioned above.

Cheap Firearms.

Cheap guns are -60% to Cost (-0.6 CF). They have -1 Acc, -1 HT, and -1 Malf. If you aren't using Malfunctions (p. B407), treat this as "16 is always a failure, and 17 is always a critical failure."

Alternatively, if you don't mind extra detail, the firearm's HT is unchanged. However, whenever it would normally get a bonus to a HT roll -- like the HT+4 roll to resist Slime, Sand, and Equipment Failure (p. B485) -- it rolls against straight HT, no bonus.
With all of the love for high-quality firearms, it's weird that we haven't come up with official rules for low-quality ones. These three drawbacks focus on the problems usually cited in real-life for cheap guns.

Note for My Players

I also have a minor house rule about Dependents and Enemies. They may be only taken with a Frequency of "6 or less" or "9 or less" without special GM permission.

Retired House Rules

Several of my house rules have been retired due either to them being incorporated as official rules or to new rules which solve the same problem in an acceptable way. I'm glad that this section exists! It means that the system is being constantly improved as it grows. Retired house rules include those for Gunslinger, Magery 0, and Off-Hand Weapon Training.

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