House Rules

for GURPS Adventures


The motivation behind the rules below is, in general, the improvement of playability. We have no focused our attention on realism, although we have attempted to avoid outright fiction. When it was necessary to make a call between realism and playability, however, we chose the latter. The game's the thing.

In some cases, we modified rules that we feel are obviously in error. (Example: Mute is -25, Deaf is only -20. But hearing is far more useful than talking.) In others, we attempted to simplify what we considered to be rule kludges. Some GURPS rules are, while perhaps realistic, a bit 'tweaky' in the sense that they apply a series of special cases to specific situations. Where possible, we have unified the rules into a single framework. The most obvious example of this is our expansion of Encumbrance.

It should be noted especially that for some of the rules presented below, it is important that they be taken together, so a GM wishing to adopt some of them should devote careful thought before picking and choosing.

Character Creation


Cost Progression below 9: Continues to decrease by 10/level, so that 8 costs -20, 7 costs -30, and so on. (Old Rule: 8 costs -15, then -10 per level below that.)


Artistic Talent: Costs 5, and allows character to double points spend in any artistic skill, as per Eidetic Memory. Also provides +2 to default skill use. (Old Rule: none.)

Common Sense: Costs 5. (Old Rule: Costs 10.)

Craft Talent: Costs 5, and allows character to double points spend in any craft skill, as per Eidetic Memory. Also provides +2 to default skill use. (Old Rule: none.)

Eidetic Memory: Costs 20. Doubles points spent in any mental skill based on knowledge. These skills include all Artistic, Language, Medical, Professional, and Scientific skills, in addition to others as the GM sees fit (Diplomacy and Savoir-Faire are two that might be considered). A skill such as Fast-Talk should almost definitely not be included (but see Empathy, below). Note that there is only one level of Eidetic Memory available now, except perhaps in cinematic games. (Old Rule: Costs 30, allows double points in any mental skill, second level allows quadruple points.)

Empathy: Costs 15. Gives +2 to social skill rolls if Empathy roll is made. (Old Rule: Costs 15, allows IQ roll to determine true loyalties and so on.)

Language Talent: Costs 10, and allows character to double points spend in any language skill, as per Eidetic Memory. Also provides +2 to default skill use. (Old Rule: Costs 2/level, direct add to any language skill.)

Musical Talent: Costs 5, and allows character to double points spend in any musical skill, as per Eidetic Memory. Also provides +2 to default skill use. (Old Rule: Costs 1/level, direct add to any musical skill.)

Peripheral Vision: Costs 5, only available as a racial advantage. (Old Rule: costs 15 points.)

Resistance to Disease: Costs 5, confers +5 to all disease-related HT rolls. (This provides a finer level of Immunity to Disease, which no one takes because it's too expensive.)


Bad Sight: Farsighted or mildly nearsighted (double distance penalties but no melee penalty) costs -10 points. Severely nearsighted costs -20. Half cost for correctable vision. (Old Rule: Either nearsighted or farsighted is -25 points or -10 if correctable.)

Berserk: Lose +4 bonus to death rolls at -2xHT. (Old Rule: Get +4 bonus to all death rolls until at -5xHT, character dies.)

Color Blind: Costs -5 points. (Old Rule: costs -10 points.)

Deafness: Costs -25 points. (Old Rule: costs -20 points.)

Fat: Costs -15/-20 points for the two given levels. (Old Rule: costs -10/-20 points.)

Lecherous: Costs -10 points. (Old Rule: costs -15 points.)

Mute: Costs -20 points. (Old Rule: costs -25 points.)

Overweight: Costs -10 points. (Old Rule: costs -5 points.)

Paranoia: Costs -15 points. (Old Rule: costs -10 points.)

Pyromania: Costs -15 points. (Old Rule: costs -5 points.)

Weak Will: Costs -4/level. (Old Rule: costs -8/level.)


Animal Handling: Mental/Easy, only covers basic care and treatment of Animals. (Old Rule: None, skill renamed to be more intuitive with what we think of as "animal handling".)

Animal Training: Mental/Hard, allows for training of animals. (Old Rule: Renamed from Animal Handling.)

Bow: Physical/Average. (Old Rule: Physical/Hard.)

Physical Skill Point Cost: Progression goes 1/2, 1, 2, 4, 8, 12, 16, 20, and so on, at +4 per level. (Old Rule: same to 8 points, but then +8 per level.)

Spear/Staff: Spear defaults to Staff-2, but Staff defaults to Spear-3. (Old Rule: Staff defaulted to Spear-2, allowing abuse of the differential between P/A and P/H skill costs.)

Specialization: Taking an optional specialization allows you to double points spent within the specialization, and take a penalty of -1 outside it (in addition to not doubling points). So spending 3 points on Astronomy (Supernovas), a M/H skill, would allow an IQ 14 character to have skill level 15 in the specialization (doubling points to 6 gives IQ+1 in a M/H), but 12 outside it (3 points gives IQ-1 in a M/H, plus the -1 penalty). Spending one more character point would raise the specialized skill to 16 and the general skill to 14. (Old Rule: bonus within specialization was +5, penalty outside it was -1.)

Character Development

Change in Stat Point Costs

Old Rule: Point cost to raise a stat is doubled after character creation.

New Rule: Point cost no longer doubled, on the grounds that otherwise starting characters tend to maximize DX and IQ in order to get skills for the cheapest values possible. Allowing characters to upgrade DX and IQ at base cost allows stat upgrades during character development without penalty and disincentivizes maximization of attributes. Note that to avoid the problem of stat-hoarding, the GM should require that points spent in stats be explained by the character story and should require that points be spent in skills that use that stat as well (see GM Notes, below).


Attacking the Weapon

New Rule: You can't do it. We don't like the current rule, don't have good ideas for replacement, and don't think attacking the weapon should play much of a role anyway. Disarm the guy, if you must.

Close Combat

New Rule: 1-hex weapons are at -2 to skill in close combat. Close reach weapons (knives, etc) are at no penalty.

Defense Rolls

Old Rule: Each active defense is rolled for once, the rolls being against PD + (Active Defense) + modifiers.

New Rule: Active and passive defense are separate. First, an active defense may be made at (Active Defense) + 3 + modifiers. If that fails, then a passive defense may be made at PD + 3. Notes: PD of shields is added to Block.


Old Rule: Disarming is a Contest of Weapon Skill, with the attacker at a penalty to hit based on opponent's weapon size (-4 for weapons of length 2+, -5 for weapons of length 1, -6 for close combat weapons).

New Rule: Defender may substitute ST for Weapon Skill in the contest, if desired. (This removes the silliness of a fencer disarming an Ogre with a Club.) Note that all non-fencers have -2 on rolls to disarm (this is not technically a New Rule, however).


Old Rule: Unknown.

New Rule: Fatigue up to ST/2 gives no penalties, but for each point in Fatigue over ST/2, there is a penalty of -1 to ST, DX and IQ. This properly accounts for the difficulty of, say, solving a calculus problem immediately after combat, but doesn't hurt you quite as badly as assessing full Fatigue penalties would.


New Rule: To grapple requires a Contest of DX to hit (modified as usual by location modifiers, etc), followed by a contest of ST to hold on. If both contests are successful, the defender is grappled. If a limb is grappled it is immobilized. If the head is grappled, the defender is at -4 DX until he breaks free. The other effects of the grapple are that (1) the victim is restrained in the current hex; (2) both fighters are at -2 to Dodge; (3) there is an additional -2 to attack with 1-hex weapons (they cannot momentarily step back to proper range as they normally could). All maneuvers made to continue grappling or to break free count as actions (attack or defense, depending).

Hitting the Head

New Rule: Aimed attacks to the head may be made at -4. If a hit succeeds by 3, the attacker may choose to hit the Brain (DR +2 and final damage multiplied by 3), or, if a thrusting attack, to hit the Face (which bypasses DR for open-faced helmets (i.e., most of them)). All head shots that do 0 or more damage require a HT roll to avoid Stun; head shots that do HT/3 or more damage automatically Stun and require HT to avoid knockout. A brain shot that does 0 or more damage automatically Stuns and requires a HT-damage roll to avoid knockout.


Old Rule: Pain equal to hits of damage taken is assessed in the turn after the damage is taken, and goes away entirely the turn after that.

New Rule: The pain calculation is the same, but is reduced at 50% per turn (rounded down). So a 3-hit shot would cause 3 pain in the first turn, 1 pain in the second turn, and nothing thereafter.

Parrying Missiles

Old Rule: Thrown missiles may be parried at -1, or -2 for small weapons.

New Rule: Large missiles (e.g., spears) may be parried at -2, normal missiles (e.g. axes) at -4, and small missiles (e.g. knives) at -6. Fencing weapons get -2 to Parry missiles.


Old Rule: Retreating adds 3 to any active defense.

New Rule: Retreating adds 3 to Dodge, and 1 to Block or Parry.


Old Rules: The wielder of a shield in close combat takes skill penalties equal to the PD of the shield. A large shield gives -2 to weapon skill in melee combat.

New Rules: No additional penalties in close combat. Medium shields give -1 to skill and large shields give -2 to any DX-based skill. Any successful Block results in the damage being taken by the shield, but Passive Defense by a shield does not result in damage being taken by the shield (clearly this is only relevant if optional shield damage rules are in effect).

Unarmed Combat

Old Rules: Boxing and Brawling give a Parry of 2/3 skill and confer a damage bonus of skill/10 for Brawling and skill/5 for Karate and Boxing.

New Rules: Boxing/Brawling Parry reduced to 1/2 skill. Boxing gets a special Dodge computed as (1/8 Boxing skill + Speed, rounded down) only against thrusting melee attacks to the upper body (defined as anything but the legs or feet). Brawling confers a damage bonus of +1 at level 15 and +2 at level 20. Boxing and Karate give a +1 bonus at level 10, +2 at level 15, and +3 at level 20.

Boxing and Brawling can parry thrusting weapons at -3, while Karate and Judo can parry thrusting weapons normally and swinging at -3. (All penalties assessed against Parry, not skill level.)

Unbalanced Weapons

Old Rule: Most could only be wielded over a certain minimum ST, and required at least one turn to ready.

New Rule: Reduction in Min ST by 2 for each weapon. We felt the old minimum ST were too high compared to other weapons, considering that they are being wielded by both arms. Allow one "Instant Ready" per turn for those with ST at least 4 higher than Min ST, or if character spends a Fatigue point. This allows a character with an awkward weapon to attack each turn, but not attack and parry.

New Rule: If a one-handed weapon is used two-handed, Min ST is reduced by 2. A very strong creature could use a two-handed weapon one-handed if he has ST at least 4 higher than the Min ST required to Auto-Ready (see above) for a net of Min ST + 8.

Other Game Play


Old Rule: Encumbrance reduces Move, but little else. It has some effect on certain skills (e.g. Karate, Fencing) which may only be practiced at Light or below.

New Rules: Encumbrance Level is subtracted from skill level for any DX-based skill, and this effect is doubled for skills currently flagged as requiring Light or below (so Karate in Medium Encumbrance would be at -4 to skill, while Broadsword is at -2). This has at least two positive effects: it makes "point-juggling" harder by confusing the breakpoints on certain skills; and it balances out armed vs. unarmed combat.

Sense Rolls

Old Rule: Senses are based on IQ, modified by Acute Senses.

New Rule: Senses are based on 10, +1 for IQ or HT of 12+ and -1 for IQ or HT of 8-, for a range of 8-12. This is then modified by Acute Senses.

Spell Casting

Old Rule: Cost to cast reduced by 1 at skill 15, reduced by 2 at skill 20, and so on. Time to cast halved at skill 21, halved again at skill 25, and so on.

New Rule: Reduce cost to cast by 1 for each 4 points of success. Take a -4 skill penalty for each halving of casting time. Spend an extra Fatigue to get +1 skill. Double casting time for +1 skill. Cast with no words or no gestures at -2 skill each (so -4 if using neither words nor gestures). Note that this helps to alleviate the breakpoint system that does not reward skills between 15 and 20 equally. It's also much harder for mages to rely on Iron Arm for unlimited parries.


Old Rule: Various. There are different rules for Leaders, whatever those are, and Combat Reflexes conferred a special bonus for Leaders.

New Rule: Surprise is equivalent to Mental Stun.

Wounds and Recovery

Old Rule: After combat, bandaging automatically restores 1 hit. A First Aid roll may replace bandaging and may restore more hits according to TL. First Aid always restores at least 1 hit (as per bandaging) except on a critical failure. Every day, make a HT roll (possibly modified by the level of medical care). On a success, 1 hit is healed. Recovery is only possible when completely restful.

New Rules: Each wound is treated separately and may be bandaged separately. First Aid may be attempted on any ONE wound taken during a combat (rationale: once First Aid has been applied to a wound, the others have had a chance to bleed and worsen, so First Aid doesn't help).

Infection: A HT roll is made for each wound (assuming it was bandaged properly and inflicted with a clean weapon, this roll is unmodified; GM's discretion on penalties in worse conditions). On a failure, infection sets in. The result of infection is to double the damage caused by the wound. Note that the character may die as a result of infection. Additionally, if hits are reduced to -HT or less as a result of infection, the character becomes delirious and diseased. Each day during this disease, a HT roll must be made to recover. Failure means death. Once any disease is cleared up, recovery proceeds normally.

Recovery: A HT roll is made for each wound each day. Success reduces the wound by 1 hit. There is no special provision for critical failure or success, although the GM may optionally rule that wounds may become infected again on critical failures during recovery. The HT roll is unmodified if the character rests completely, and is at a maximum of -4 if the character pursues normal activity. GMs are encouraged to adopt a continuum of modifiers between these two extremes for in-between cases.

GM Notes


The rules presented above, especially the changes in costs for attributes during character development, do present some possible complications for the GM. The primary rationale for GURPS to double point costs for attributes after character creation appears to be that it is unbalancing for characters to load points into attributes. It is certainly desirable to avoid this unbalancing effect, but we feel that the solution of doubling costs is just as unbalancing the other way (since it penalizes attribute spending to the point where it is simply never done).

Therefore, we have two suggestions for GMs that use these house rules, regarding the spending of earned XP. First, earned XP should be spent immediately upon earning it. If the points spent are not sufficient to raise the skill, stat, or attribute, or to buy off a level of a disadvantage, then there is no value gained therefrom (that is, a character with two points in Alertness still has no Alertness). For game balance purposes, this character should not be considered to have these points (thus, if the character above was based on 100 points and the player spent his first two points on Alertness as described, then the character would still be 100 points, not 102 points). The effect of this rule is to limit the "starving and bingeing" pattern that a player trying to raise an attribute or other large-point-cost item will often assume, as savings of points for the item are superceded in importance by lower-cost items.

Second, we propose that GMs should limit points spent in attributes to no more than the number of points spent on skills based on that attribute, thus avoiding the problem of spending points on nothing but attributes. Furthermore, the GM may impose spending caps on attributes or any other single item to further slow advancement.

Default Skills

We had a fairly large argument over the way the book uses skill defaults. While the general concept seems sound, some players may be able to abuse the system by buying one 'key' skill from which many others default at only a small penalty. Then every defaulted skill may be raised by spending points only in the 'key' skill.

In the end, however, we decided to leave the book rules alone, with the following caveats: physical skills that default from mental ones are dangerous and should be watched carefully for abuse (one might even drop the default altogether to avoid this problem), and, in general, any cross-stat default is an open door to abuse; even same-stat defaults can be abused, but we trust that GM control over XP awards should go far to reduce the abuse. Note that one rule which might be adopted to curb the problem would be to limit skills known only by default to the base stat of that skill.

Ad/Disad Package

An idea posed by the GM of the Methoria campaign, that we think is just terrific, is to require that all PCs take a Sense of Duty to friends and companions, coupled with 2 levels of Hard To Kill. This combination is worth 0 points and has the combined effect of improving player unity and player survivability. This is such a laudable goal that we intend to use this rule in all applicable campaigns.