Diffuse

Diffuse is form of Injury Tolerance that includes all the benefits of No Blood, No Brain, and No Vitals.Basic Set: Characters, p.60 Creatures with Diffuse take only 1 HP from impaling and piercing attacks, and 2 HP from other attacks (such as crushing and cutting). Area-effect, cone, and explosion attacks cause normal injury.Basic Set: Campaigns, p.380
Base cost: 100 points 
Creatures with Diffuse are usually fluid or particulate, composed of a swarm of smaller entities, or perhaps made of pure energy. Diffuse creatures are usually immune to grapples,DFRPG: Monsters 1, p.10 although there are some natural exceptions--for instance, grabbing a ghost with special ghost-grabbing gloves, or using Pecos Bill's lasso on a cyclone.Story here Furthermore, diffuse objects that can be readily grabbed, such as nets and mattresses, are grappleable.DFRPG: Exploits, p.55 
== Countering ==
Creatures with Diffuse are difficult to injure with most attacks, but they are vulnerable to most "area" attacks. In magical settings, this may be as simple as casting Concussion.See also, Elementals -- even if not vulnerable to a particular element, they are always damaged by spells that destroy or manipulate their element! 
In non-magical high-tech or utlra-tech adventures, Diffuse enemies will mainly be swarms (such as bees, ants, or tiny robots). Thesedealt with via explosives, high RoF weapons (birdshot in a shotgun, for instance), or "areas of damage"--it can be very effective to trick a swarm of beetles into a pool of flammable oil, or a swarm of microbots across a sabotaged, electrified floor!
==Special Modifiers==
*Infiltration (+40%)Horror, p.14-15
*Body of Swarm (+0% or +40%)
**Flying Swarm (+30%): Requires Body of Swarm (unclear why 30% of 80 point ability, since flight costs 40)
**Humanoid Form (+50%): Requires Body of Swarm
**Scatter (+40% or +120%): Requires Body of Swarm
*Swarm (+80% or 160%) note: includes Infiltration so could be thought of as +40 or +120 if wanting to list it separately
H14 clarifies that Powers' Swarm is the combination of Scatter and Infiltration.
Since Scatter has the new prereq of 'body of swarm' (it did not in Powers) this is assumed to be the +0% version since the total is exactly that of S+I.
The +40% "with full infiltration" is probably just getting Infiltration.
"dispersed by injury equal to your HP" is the new rule for BOS which apparently should retroactively apply to Powers' Swarm too. This is now a disadvantage since 0 HP = unconscious, not a guarantee for non-swarms.
"enough to kill" at -HP is probably implying normal rules of HT rolls though, which could be avoided with Unkillable.
H15 has limitations:
*Misty
*Tenuous Form
Misty apparently includes Infiltration so it's more like a metatrait, much like Affects Insubstantial is a net limitation which includes the Affects Insubstantial enhancement. This means if taking into account Scatter's 40/120, the -20/-40 of misty is a much bigger minus. The "if not" is basically +40% -60% = -20%. Mag/psi is a limited form of ability (normally could do physical attacks) so has unequal comparison.
==ITs it does not include==
Blood/Brain/Vitals are the only thing Diffuse explicitly lacks and doesn't need to buy off...
Things it does not explicitly include are:
*No Eyes
*No Head (it has it partially via No Brain, but lacks No Skull and No Face)
*No Neck
*Homogenous (they take reduced damage from AE impaling/piercing, Diffuse does not)
*Unliving (they take reduced damage from AE impaling/piercing, Diffuse does not)
===Hills Have Eyes===
The Shadow template from PK at http://www.sjgames.com/pyramid/sample.html?id=5583 purchases No Eyes distinct from Diffuse taking the approach it is not included.
*"Immune to Crippling injuries" from B60 would mean they could not be blinded
Things which would still apply:
*DR: it doesn't apply to eyes unless you take a force field, so if you have DR, you still have an "eye location" which can be targeted to ignore that DR
**this includes Skull DR as usual, unless a Diffuse character also takes No Skull.
***there isn't actually much reason to target the skull (since there's no brain under it) since any penetrating damage (it still has DR) is treated like face hits
****but see below for motive via hit locations
===Swarms Have Necks===
Diffuse and No Neck are paid for separately by PK at http://www.sjgames.com/pyramid/sample.html?id=5583 which implies you can have a character who is diffuse but still strangle them
*there appear to be problems with grappling diffuse characters though: if it's at all possible, it may create problems for trying to do SPECIFIC grappling for things like necks
**note however that Body of Water is Diffuse and Slippery, and a major value of that is anti-grapple, so the points would be wasted if you could not
***a better explanation is "can't be grappled" applies just to the new Swarm enhancement which emulates Insubstantiality
****"I don't know what to grab" for "swarm of flies" and similar might also be explained as Obscure
===Books Have Spines===
The spine as a hit location should still exist for Diffuse characters. So there would still be a 3DR targetable location.
Keep in mind for characters who specialize in stuff like Backbreaker or Wrench Spine.
*as with necks though, the ability to "grapple" a diffuse character is questionable, but setup for this only requires a TORSO grabble, which is the most basic location to grapple if it was allowed
One benefit to targeting the spine is there is no "excess is lost" like when using Wrench Limb or Wrench Neck, and those might not even be options for some diffuse characters who are Legless or who ALSO have No Neck
The downside is the usual benefits of surpassing the Spine DR (crippling) do not apply to diffuse characters (who sort of have Indestructible Bones maybe without being bones at all) who are immune to that. So it's only useful for injuring them, and that as usual is capped to 1 or 2.
===Rolls Have Joints===
Diffuse Limbs would still have joints on their limbs and extremities, there's just not much incentive to target them unless you just happen to specialize in that as a Targeted Attack anyway.
You may not KNOW a character is diffuse (it may not be obvious) and choose to target those places.
It would still be possible for a Diffuse character to buy DR (Joints Only) or something along those lines, expecting such attacks, as a cheaper option than buying all-around DR.
There's no actual benefit to injuries dont to joints though, because lowering the crippling threshold doesn't help when you can't cripple their limbs anyway.
===Rivers Have Veins===
Veins and Arteries would still be existing hit locations too. As above, if someone specializes in that technique, they should still be able to use it if that might be more appealing
*for example "Leg Artery" is -4
*for example, "Neck Artery" is -7 to hit, TA can buy it down to -3 which is easier to hit than the usual -5 to hit the neck as a whole w/o veins
There's just no obvious benefit from targeting them because it can't change the wound multiplier applied to Penetrating Damage.
==Don't Get A Head OFFUSE==
===Walls Have Ears===
No Nose is included in No Face (MA says No Head removes nose) but Diffuse characters aren't headless
This would make Ear Clap a possible attack to try and induce Deafness (which is not the same as slicing off the ear and crippling it)
If/when it is possible to grapple, having ears makes it easy to LEAD THEM AROUND BY THEM per Technical Grappling
===Thumbs Have Noses===
No Nose is included in No Face (MA says No Head removes Nose)
===Cliffs Have Faces===
Diffuse does not include "No Head", so Diffuse characters still have a "face" hit location. They technically have a SKULL too (unless they take the No Skull disadvantage baked into "No Head"), there's just little incentive to target it from the front at -2 because Penetrating Damage against the skull just counts as a normal face hit due to No Brain
Targeting the skulls of Diffuse characters from behind could be preferable due to how the penalties change in Martial Arts: it's merely -5 to hit, easier than reaching around to hit the face at the -7 it suffers from rear attacks.
The incentive for targeting the face or skull of diffuse characters still exists, though a major motivation is removed:
*B400 "Ignore all knockdown or wounding modifiers for hit location" means that there is no change in standard knockdown rolls for major wounds
**Diffuse essentially has a PARTIAL version of "No Face" by ignoring the most major drawbacks of faces (knockdown rolls without a major wound, penalized knockdown rolls on major wounds) and other problems, like Corrosive Attack doing more damage to it.
On a naked diffuse character, it's generally simpler to just target the torso at -0 (chest at -0 as of Low-Tech) because all you're ever going to do is 1 or 2 damage.
FOUR vulnerability remains (and why a diffuse character MIGHT want to take "No Face") is:
*faces can be bit: MA115 unlike skulls. You can bite a torso too, but maybe the diffuse character has torso armor but not face armor: having a face means needing to buy more armor!
**grappling might matter too if it's possible because if you grapple the head then you'd get full Active Control penalties against any dodges to attacks against it, instead of half penalties if you attacked the torso
***in some cases you can only attack the head but not the torso, like if you do an aggressive parry against as bite or headbutt, though Diffuse characters could avoid that by not using thsoe attacks
*B405 Liquids to the Face at -5 is possible, which hits the eyes too on a critical success. It allows targeting the eyes at a lesser penalty.
**this also might be interpreted as how Eye-Rake or Eye-Gouge work in some regard
***if not then Technical Grappling has rules for getting bonuses to adjacent locations by expending CP so grappling face would definitely give bonus to hit eyes with following attacks
*a Corrosive Attack targeting your face will damage your eyes, which otherwise cannot be targeted or damage by Corrosive Attack
**this is bad news if you enjoy Eye DR from Nictitating Membrane
*having a head means different results on the critical hit location table per 556. None are 'wound multipliers' or 'knockdown modifiers' which are the only things Diffuse says is off limits, so they would all apply
**one of the results is COMPLETELY ignoring DR.
**another is hitting the eye, even if an attack normally could not (like crushing)
**another is knocking off balance
**another is deafening or scarring
**halved DR and major wound as a single result instead of separate
==Contradictions==
http://forums.sjgames.com/showthread.php?t=16768 highlights
*Page 60, under IT: Diffuse “This makes you immune to crippling injuries”
*Page 400, under Injury Tolerance and Hit location: Diffuse and Homogeneous “(Eyes and limbs can still be crippled)”
alleged Kromm clarifier at http://forums.sjgames.com/showpost.php?p=253282&postcount=19 
:What happened is that a further qualifier was clipped from within the parentheses on p. 400. That should read, "(Eyes and limbs can still be crippled, if Homogenous.)"
=== weakness relative to Homogenous ===
One major vulnerability to Diffuse is that Area/Cone/Explosion attacks do NORMAL INJURY.
Although this is identical to Homogenous for Crush/Cut/Burn/Fatigue/Corrosion attacks, this makes Homogenous the best way to lower injuries from AE impaling/piercing attacks.
One way to lessen that impact is via the Swarm enhancement, which if you spread out, reduces % damage taken to % of your swarm in the AE.
This still makes Homogenous the best way to avoid damage against wide-scale AEs from those types though. Aside of course from Insubstantiality, which can be overcome with Affects Insubstantial.
Shadow Form is a lesser known countermeasure since it is NOT overcome by Affects Insubstantial: there is absolutely no way around B83's halved damage from physical attacks. This makes it better than F128 taking Illusory Form on insubstantial.
=== pricing breakdown precursor ===
"No Brain or Vitals" can be collectively considered a 10-point metatrait.
Combined with Unliving's 20, this is 30 points.
This means the extra 10 points Homogenous is worth compared to them covers the respective difference in injury multipliers going from UL>HG:
*impaling or huge piercing drop from x1 to 1/2 (50% reduction)
*large piercing drops from 1/2 to 1/3 (less than 50% reduction which would be 1/4)
*piercing drops from 1/3 to 1/5 (less than 50% reduction which would be 1/6)
*small piercing from 1/5 to 1/10 (50% reduction)
HOWEVER: 
By comparison: P53's Damage Reduction has a base cost of 50 points for 1/2 injury: it would require -80% in limitations to reduce cost to 10 points. It can benefit from DR type limits but "standard damage type" is only worth -40% and that would only apply to the 4 piercing types and not impaling!
Part of the reduced costs might have to do with one lesser-known disadvantage Homogenous has in respect to Unliving: reduced Cover DR for purposes of Overpenetration which per B408 is 1/4 HP instead of 1/2 HP. This reduces Homogenous' targets ability to protect allies behind them using Sacrificial Dodge.
This is also a disadvantage Unliving has in respect to those without IT: 1/2 HP cover instead of 100% HP cover. Which probably also account's for Unliving's inexpensive cost of 10 points while nearly also giving 50% Damage Reduction to all piercing AND impaling.:
*specifically it reduces Impaling/Huge by 1/2 (x2 to x1) and Large Piercing by 2/3 (x1.5 to x0.5) and Piercing by 2/3 (x1 to x1/3) and Small Piercing by 60% (from 50% to 20%)
=== pricing breakdown final ===
Diffuse has all the benefits of Homogenous (except possibly Cover DR, which is never defined for Homogenous but is assumed to be max 1 HP regardless, based on the pattern of it suffering whatever injury divisor that impaling does) plus the benefits of No Eyes (can't be crippled) and No Blood.
"No Blood or Eyes" is effectively a 10-point metatrait
B60 subtracting that 10 and the 40 point value of Homogenous (50) from the 100 value of Diffuse leaves 50 points representing the remaining benefits.
Due to immunity to limb crippling, the value of P53's Unbreakable Bones (10 points) can also be subtracted, leaving 40 points. Diffuse is actually better since UBB actually only makes it harder to cripple (and impossible to permanently cripple).
Since the neck (read: spine) can also be crippled, some aspect of "No Neck" is also included in Diffuse. B61's 5-point value may not entirely be present though, because since Homogenous also "ignores all injury multipliers" meaning that the "3 Cs" effect of the neck (increase crushing/cutting/corrosion injury) is absent already in Homogenous (similarly since no multipliers are used for a Homogenous face, elements of No Face are also present: no increase from corrosion)
Since 400 also specifies that Homogenous "ignores all knockdown modifiers" this also means that hits to the face/brain/eyes this means that there is no automatic HT roll if shock is caused, nor a -5 on the knockdown if a Major Wound, just the standard unmodified HT roll on major wounds in general. This is effectively having elements of "No Face" already incorporated into it.
*No Face has a hypothesized value of 4 points due to "No Brain or Skull" basically having a 3 point net value (5 for no brain -2 for No Skull) and No Head having a 7 point value.
*No Face presumably includes the No Nose perk and No Ears perk from The Weird, meaning the face remainder would only be worth 2 points.
*No Jaw (despite being a face sublocatin) has never really been addressed. It may be impossible. There isn't even a No Mouth option anyway. However presumably if someone lacks a face, the jaw would be instead on the torso and thus suffer torso wounding multipliers, not face multipliers.
==Cover DR==
GURPS Low-Tech pg 59 regarding the Net
:as it’s Diffuse (p. B380), it will only stop 1-2 points of damage if used to block
Alternatively, some precedent might be found on Animation for TK per H19
Level required to animate is HP for Unliving, HP/2 for Homogenous, HP/4 for Diffuse.
Given that in the first two cases, this is double the normal cover DR (HP/2 unliving HP/4 homogenous) one could derive from this that Diffuse gives cover DR of HP/8.
That approach allows it to scale, unlike a fixed 1-2.
==Powers==
:Injury Tolerance (Diffuse) might let Talent aid resistance rolls against Affliction (Advantage, Insubstantiality)Powers, p.158
Since Reliable works like talent, this basically allows people to buy an enhancement on this to resist the affliction based on the trait it adds, rather than resisting power sources.
+5% per +1 effectively costs 5 points per +1 to resist that Affliction though, Talent could possibly be cheaper depending on what power modifier Diffuse is bought under, but Talent is often limited to 4 while Reliable is limited to 10.
== Examples ==
* A swarm of locusts (or a mummy in locust-swarm form)
* A water elemental
* A cloud of swarmbotsSee Ultra-Tech, p.35
* A monstrous gel, from beyond the starsSee Monster Hunters 5: Applied Xenology, p.27-29
==See Also==
* Compare to Homogenous.
* Humanoid Form
* Humanoid form only
* Injury Tolerance
== Notes ==
== References ==
Category:Advantages