textfiles/rpg/invisi.txt

***********[ DE RE INVISIBILITAS: A DM'S ENCYCLICAL ]*************

"That I might drink, and leave the world unseen,
 And with thee fade away into the forest dim."
                       - Keats, TOde to a NightingaleU

Recently, questions have been raised in my campaign concerning the role 
of invisibility, especially when combined with spells and items which 
hinder magical detection. This treatise is designed to serve as a final 
ruling and an advisory, in order that characters in my campaigns may 
conduct themselves accordingly. It is being posted to CompuServe in an 
effort to assist DMs who may be experiencing similar difficulties.

The rulings herein draw heavily from the PHB2 and DMG2 spell and 
magic item descriptions. An article in Dragon Magazine #105 also proved 
helpful in places, but the most useful sources (as always) were simply 
sufficient thought, some common sense, and concern for play balance. 
Naturally, this source is only an advisory and its status thus rests solely 
with its perceived elegance and persuasive power; having said that, I 
hope that you like it.

The 'Net being what it is, I would certainly encourage any thoughts, return 
posts, and debates concerning these rulings. They withstood the "Sean 
Copeland test," so I'm pretty confident of their soundness, but I'm always 
interested to see how others react and to listen to their opinions. My time 
is a little tight right now, but if you have a question, leave me a message 
via the Forum and I promise to respond.

--"Thalion Envinyatar"
  (Joseph Katzman: 72427,3033 / Joe_Katzman@mail.magic.ca)



& INVISIBILITY IN GENERAL:

Invisibility does not actually cause its recipients to disappear; for that, 
one must use dust of disappearance. Think of it instead as a more 
powerful form of the Sanctuary spell, which encourages others not to pay 
attention to some of the things which they do in fact perceive through 
their visual organs. If youUve ever driven through a stop sign or been 
asked what colour a pretty girlUs shoes were, you understand how this 
phenomenon works. Filtering for significance is a natural trait, inherent 
in all creatures; invisibility just gives it a helping hand.

Several logical consequences flow from this definition:

%	Invisible persons are not fooled, and can see themselves; ditto for a 
spell-caster who casts the spell on another being.

%	Invisibility is not proof against magical traps, etc., which have no 
TattentionU to divert. Sort of like Tthe camera never lies.U Ditto for mindless 
creatures like skeletons or automata (e.g. Golems).

%	Since invisibility relies on diverting attention and perception, detect 
magic spells will NOT reveal an invisible character. The spell imparts the 
data, but the caster filters it out as inconsistent unless the invisibility can 
be overridden somehow. The same is true for infravision and ultravision, 
but not for wavelengths which are higher or lower in the electro-magnetic 
spectrum.

%	Beings with more than 10 HD and 13 Int., however, have an automatic 
chance to detect invisible creatures, expressed as a saving throw vs. spell. 
Presumably, those beings which save successfully find that the spell is 
unable to completely override their inherent strength and mental acuity, 
though the spell still functions and may succeed against others. Note that 
this does not usually allow them to RseeS the character, however; instead, 
itUs sort of like the Ttip of the tongueU phenomenon with words - they know 
that something is there, but canUt quite place it. Hence the -4 to AC and 
+4 on saves.

%	Creatures who rely on other senses besides sight do not have their 
other sense data filtered, and may perceive invisible creatures more 
easily; indeed, in some cases (bats, scorpions, et. al.) they may not be 
aware that the creature is supposed to be invisible at all. Less powerful 
beings with great sensory acuity may also get saving throws, as noted 
above. Presumably, those who make their saves are paying attention to 
this other sensory data, and the cognitive dissonance this creates allows 
them to detect that something is amiss.

	Being attacked , however, is a pretty hard message to ignore, and will 
trigger certain deeply embedded defensive responses even if the attack 
does not register at the conscious level.  Engaging in such activities thus 
draws opponentsU attention to you in such a decisive fashion that 
invisibility becomes ineffective immediately thereafter. Overwhelmed by 
the metal backlash, the RscreenS then collapses.

Finally, it should be noted that Magic Resistance is no more effective 
against invisibility than it is against other forms of illusion. It confers NO 
benefits.


& IMPROVED INVISIBILITY:

A more advanced form of invisibility, whose greater power is aimed at 
the maintenance of the perceptual screen despite actions (like attacks) 
which would cause the less powerful version to collapse. Think of it as a 
steady barrage of reassuring suggestions aimed at a variety of conscious 
levels, rather than a single suggestion aimed at the conscious level.

Of course, this power has a price, in that the spell has a definite duration 
and will burn itself out much sooner (rounds instead of 24 hrs.). In 
addition, it is never completely effective, as the results of attacks and 
other sense data still register in the victimUs mind. As such, it is possible 
for suspicious opponents to partially override its effects in the same 
fashion as an active invisibility dweomer Rafter the invisible character 
has made his presence knownS [PH 2, 159]. 

The spellUs greater breadth and comprehensiveness also provide benefits 
against creatures which would normally be able to detect invisible 
opponents, reducing their saving throw categories by 2 HD.


& DUST OF DISAPPEARANCE:

The real thing. Actually bends the electro-magnetic spectrum around the 
individual, thus causing them to disappear from electro-magnetic 
perception entirely. Think of it as a sort of super-stealth technology, 
which unfortunately tends to Rflake offS with time (2-20 turns if sprinkled 
haphazardly, 11-20 turns if carefully applied).These properties give Dust 
of Disappearance several advantages which invisibility does not have, but 
there are limitations. While Detect Invisibility spells are ineffective, 
spells which actually augment perception instead of just enhancing it (i.e. 
Detect Evil, True Sight) will function properly. Furthermore, the recipient 
still gives off some information. If you roll in a dunghill and then sprinkle 
the dust on, you still stink. If you walk on dry leaves, you still make noise. 
If you walk at all, you still create vibrations in the ground which some 
creatures (esp. snakes and scorpions) can detect. Admittedly, all of these 
factors can be mitigated by prior preparation, but they are not conferred 
automatically.

One final note: a dragonUs ability to detect invisible creatures in its lair is 
a function of its deep attunement with its immediate environment. A 
creature using the dust would thus be detected as present, though the 
dragon may not be able to tell who or what it is. A similar principle holds 
true for those using Commune With Nature spells, unless the dust was 
applied within the spellUs radius; in that case, the act of application may 
well be revealed, and appropriate conclusions drawn thereafter concerning
any Runidentifiable effects.S



% DETECT INVISIBILITY:

This spell relies primarily on improving the recipientUs perceptual filters 
and concentrating their attention in order to enable them to notice 
invisible, out-of phase, or concealed creatures. As noted in the PH 2, 
pg.141, however, it does not confer the ability to see through physical 
objects such as a door or even a boulder, though hiding in underbrush 
would cause one to be revealed. Note that this allows the recipient to 
clearly see such creatures as if they were not invisible or hidden at all! 
Magic resistance offers NO protection, as this spellUs power is focused 
exclusively upon its caster.

It would appear that most creatures have some latent ability to perceive 
the ethereal, as evidenced by dreams and by some peopleUs stronger 
innate sensitivity to ghosts, spirits, and things supernatural. Except for 
these rare individuals, however, such abilities appear to operate below 
the threshold of  consciousness. This spell brings them to the fore, 
allowing its recipients to clearly see ethereal or out-of-phase creatures.

The parallel ability to detect astral creatures and even perceive their 
silver cords by means of this spell is a matter of some interest and debate 
among sages. Some theorize a subconscious innate ability similar to that 
which applies to ethereal things, though they have difficulty pointing to 
any analogous RcommonS experiences. Others argue that this dearth of 
analogies is proof that the spell must actually augment perceptions in 
certain limited ways. Research continues.


% DIVINATORY INVISIBILITY: NON-DETECTION

An extremely useful spell for those who value their personal privacy but 
have not yet achieved Mage-class status as a Master of the Third Circle; 
indeed, several wizards have been known to use this spell in combination 
with Extensions in order to provide continuous coverage.

Casting this spell provides complete resistance to scrying of all sorts, as 
well as spells like ESP and most other detection or divination-type spells. 
In my campaigns, it also prevents aura readings like know alignment (just 
as the amulet and many similar items are known to do), although the 
resulting Rnull readingS often does at least as much to provoke suspicion 
as any information which may otherwise have resulted. In general, 
therefore, it is most effective against spells like Detect Evil and Detect Lie, 
which normally provide information only if their conditions are violated.

Non-detection is not foolproof, however. Contact Other Plane may result in 
useful information if the being contacted is sufficiently powerful (5% 
chance, +5% per plane removed), and a Commune spell is always effective 
if the matter is one which concerns the religion. True Seeing/ True Sight 
spells are also effective (except with respect to aura readings), as their 
power is generally sufficient to overcome the spellUs barriers. Finally, 
Divinations and other prophetic spells may work if the non-detection 
caster fails a saving throw vs. magic.

Of particular interest, however, are this spellUs known interactions with 
Invisibility of all types. Since Detect Invisibility largely affects the caster, 
it remains effective even against a being cloaked by non-detection. 
Nevertheless, a subtle interaction between divinatory and perceptual 
invisibility appears to exist, as evidenced by the fact that such creatures 
cannot be clearly seen for what they are unless more powerful magics like 
True Seeing are employed. Detect Invisibility, therefore, will only reveal 
general details (rough size and build, biped or not, humanoid or 
monstrous, etc.). Rogues often find this result extremely convenient, as do 
assassins. Treat this special effect just like the natural detection ability of 
certain powerful creatures, therefore, albeit with a 100% chance of 
success.

One other extremely valuable aspect of this spell is its ability to foil 
magical traps whose triggers are based on inherent traits rather than 
effects. A glyph designed to detonate in the presence of good clerics or 
elves, for example, would remain inert, while one triggered by crossing at 
threshold without speaking its name would remain effective. This 
weakness can be alleviated somewhat by employing negative conditions 
(i.e. Rany non-evil beingS), though this has the disadvantage that cloaked 
creatures who do fit the requirements will then become vulnerable.

*********
JOE KATZMAN, 1994;