Physical invisibility	Mind-Control invisibility	Illusionary Invisibility	Questions and answers about illusionary invisibility	New spells
Conclusions	-	-	Dragon 105	Dragon

Invisibility is a wonderful thing. It is used
in many adventures and is a basic power
that many characters depend upon. However,
despite how often it is used, it is one of
the most misunderstood spells in the
AD&D® game. This article explores invisibility
powers in depth.

A look at the invisibility spell as described
in the PH shows that the
spell is an "illusion/phantasm." This is
contrary to the way it?s understood to work.
In most game play, the spell is not treated as
an illusion, but rather as something that
affects the physical world. Many references
in the AD&D game books imply that the
spell somehow bends light waves around the
recipient, thus rendering him invisible. This
raises many questions. What causes us to
think of invisibility this way? What is the
correct way to deal with invisibility? What
was originally intended? What implications
does this have for AD&D gaming?
The PH and the DMG contain descriptions of many
spells and objects that confer invisibility.
They can be divided into three categories.

Physical invisibility is that bestowed by
an item or power which causes light waves
to be actually bent around the invisible
object. In this class we find only dust of disappearance.

Mind-control invisibility is a direct
mind-affecting power. It includes the minor
psionic discipline called invisibility as well
as the druid?s invisibility to animals spell.
The cleric spell sanctuary is assumed not to
confer any sort of invisibility as such; enemies
are assumed to be able to see the cleric
using such a spell, but the cleric?s deity (or
agent thereof) causes the enemies to believe
that the cleric is unimportant or harmless,
thus sparing the cleric any attack or attention
that might otherwise be directed toward
him.

Illusionary invisibility is the sort bestowed
by several spells used by magic-users
and illusionists, such as invisibility, invisibility
10' radius, mass invisibility and
improved invisibility The effects of most
magical items that confer invisibility, such
as a potion of invisibility or a ring of invisibility
are also in this category.

Some spells or magical items confer a
power similar in some ways to invisibility,
such as a cloak of elvenkind or robe of
blending. These powers are closer to a
chameleon's powers than to real invisibility,
and they will not be considered here. A
thief's hiding in shadows skill also falls into
this category, and will not be discussed.

Physical invisibility
As mentioned earlier, there is only one
known example of an item that bestows this
power: dust of disappearance. This magic
dust has the power to bend the rays of light
as they pass near it. This causes light not to
strike the object the dust is sprinkled over,
rendering it invisible because no light reflected
from it reaches the eyes of the viewers.
This is the only ?real? invisibility in
the game, and is also the only power that
can turn something non-living invisible.
The other spells only affect a single living
thing and any possessions being carried.
The DMG, p. 143,
says that the dust's effects are not negated
by a normal detect invisibility, but are
negated by dust of appearance. The dust
has an undependable and limited duration
(2-20 turns), but while it is in effect, invisibility
from it is not negated if its subject
makes an attack.
Apparently, detect invisibility does not
work against dust of disappearance because
the spell is potent against illusion-type
invisibility only, acting as a limited detect
illusion. The dust causes a physical change
in the world, so it cannot be detected as an
illusion.

Mind-control invisibility
Psionic invisibility is a power that affects
its victims through direct mind control; in
this sense, it is more of a charm than an
illusion. It forces the victim?s mind to disregard
what his senses tell him is going on,
without altering the real environment.
Illusions, on the other hand, change the
sensory information and not the mind itself.
Psionic invisibility is thus more powerful
than the illusionary spell form, despite its
limitations.

The power is interesting in that invisibility
will be conferred only upon the caster
himself, and only be effective against those
people or creatures he specifies. Thus, the
power is neither infinite in duration nor allinclusive
in scope. If another enemy walks
in the room, the caster may not have the
ability to extend his invisibility to affect the
newcomer (depending upon how many
creatures he's already affecting).
This power is so strong that it completely
neutralizes all attempts to see through the
invisibility. Even if the victim decided to try
a detection spell, his mind wouldn?t let him
believe the results. Therefore, detect invisibility
or dust of appearance will not show it
for what it is.

It must be possible to use a psionic discipline
while making physical attacks against
an opponent; otherwise, a power such as
body weaponry would be fairly useless.
What the PH does not say
about psionic invisibility is what happens if
the invisible character physically attacks
someone who cannot see him: The victim
will not realize the attacker is present, thus
granting the attacker an enormous advantage
in any combat situation, especially in
the first round.

An invisible attacker should be allowed
one complete surprise attack. The armor
class of the defender should be adjusted to
disregard any applicable bonuses for dexterity
and shield, and in most cases any other
directional bonuses (such as for cover). The
attacker can take his time and line up a very
accurate spell attack, weapon thrust, or
missile shot. The DM may want to grant an
extra bonus "to hit" in this case as well (+1
to +4, depending on circumstances), since
the defender has no idea he is about to be
attacked.

On all subsequent rounds, the defender
will have been alerted. However, if the
mind-control invisibility is still affecting
him, he will not know what is attacking him
or where it is. He will try to defend himself,
moving his shield toward the direction of
the last attack, and may possibly try to
escape. For subsequent rounds, he still
cannot use his dexterity bonus to AC, but
his shield (if any) should be usable if the
situation-allows. Attacks against the invisible
character are made at -4 ?to hit,? if they
are possible at all.

Invisibility to animals is classified as a
type of alteration magic in the Players
Handbook. The spell works like a selective
psionic invisibility It reaches into the minds
of animals and makes the caster totally
unseen to them, just as the psionic power
does to characters. The effect is similar even
though the cause is different (a spell instead
of a psionic discipline), but the spell is quite
different in some ways from the psionic
power. The effect of the spell is somewhat
weaker than psionic invisibility, since it only
works on dumb animals. Like most spells, it
has a finite and fairly limited duration.
And, as with all spell-induced forms of
invisibility, the spell "does not allow attack"
(DMG, p. 60); the magic is dispelled if the
druid makes an attack against a creature
that cannot see him.

Illusionary invisibility
Invisibility spells classified as illusion/
phantasms in the PH affect
the visual senses of the victims. There is no
saving throw allowed and no chance to
disbelieve. However, in something similar
to a disbelief roll, there is a chance for highlevel
and intelligent creatures to overcome
the spell.

There are many inconsistencies surrounding
illusionary invisibility spells. On
one hand, they are written as illusions; on
the other, they are referred to in ways that
imply that they actually alter the light waves
around the caster. For example, check the
description of psionic invisibility in the
PH, p. 113. The text says
that ?. . . only a mind bar is able to prevent
the power from operating with respect to
[the recipient of the mind bar], for this
power affects minds, not light waves or
similar physical manifestations.? This
clearly implies that normal invisibility is
physically oriented.

The DMG (p. 59) explains the problems
a caster may have with invisibility. It points
out that if others deduce that an invisible
person is in the area, they will take actions
to thwart him. For example: ?Think of a
door opening without any visible cause; this
will cause suspicion in the mind of the
viewer.? This is a very strange thing to say
about an illusion-class spell, as most illusions
are negated or at least compromised
when someone knows what?s going on. This
also implies that the power is something
other than an illusion.

Take a look at the next page (p. 60). It
says: "Dust of disappearance does not
negate sound or odor either, so it is basically
the same as an invisibility spell." This can
be interpreted in several different ways, but
it seems to imply that dust of disappearance
(a physical invisibility device) is the same as
the illusion-based invisibility spell.
While they do not affect the mind directly,
illusions certainly do not affect light
waves, either. An illusion spell should be
treated like a projection screen. The illusion
flashes something up on this ?screen,?
hiding something behind it. The senses of
the victim register what is seen on the
screen and can't see what?s beyond it. Note
that invisibility is a visual screen only; noise
and odors are still detected.

If the spell were truly an illusion, then the
realization that invisibility was afoot should
be enough to dispel the magic, or at least
greatly reduce its effect on observers. This
does not happen. In addition, illusions
usually do not affect the friends of the
caster. Again, the DMG seems to say the
opposite. (See p. 59: "Furthermore, the
associates of the invisible party are not able
to see him or her any better than foes are,
so this can cause problems, too.")
But let's not get carried away We should
not reverse the intent of the spell and call it
a physical manifestation; this would just
create other problems. The fact that the
spell turns itself off after an attack is made
suggests that it?s an illusion, and as such
would have no effect once the observer is
unmistakably convinced (by the attack) that
an illusion was present. Changing the invis-
ibility spell is certainly not the answer.
Much has been written that seems to point
either way. If we make any decision, we
have to contradict the written word, somewhere.
It?s a matter of deciding what makes
the most sense to the game, and trying to
figure out what definition was originally
intended.

Invisibility, as written, is an illusion/
phantasm spell, and this is undoubtedly
what was intended for it. What remains to
be done is to clean up the interpretations
made with respect to this spell, involving
some subtle changes in the way in which
most people play it.

In the next section is a list of questions
about the illusionary invisibility spell. None
of these are official game answers; they are
merely suggestions for play of the spell.
Following this, two suggestions for new
spells are presented. The first is based on
physical invisibility, and the second on
mind-control invisibility.

Questions and answers on illusionary invisibility

New spells
If the DM allows new spells to be researched
or discovered, here are a couple of
ways for magic-users to make use of the
other two types of invisibility. Illusionists
should not be allowed to research or use
these spells, simply because they have nothing
to do with illusions.

Physical Invisibility (Alteration)
Level: 5
Components: V, S, M
Range: Touch
Casting Time: 4 segments
Duration: 5 rounds/level
Saving Throw: Special
Area of Effect: Creature touched

Explanation/Description: This spell
causes the recipient to vanish from sight
and not be detectable by normal vision or
infravision. The spell works similarly to
dust of disappearance, which is described in
the DMG. It bends the
light waves in the immediate vicinity of the
recipient so that no light from his body
escapes; therefore, he becomes invisible.
The invisible creature is not magically
silenced with respect to noise, nor are his
smells or tracks masked.

Dust of appearance or a successful casting
dispel magic will negate this spell. Dispel
illusion or detect invisibility will have no
effect on this spell. True seeing or a similar
power will allow its caster to see the invisi-
ble person for as long as the true sight is in
effect. Any character may have a chance to
detect the invisible object or creature, but if
the invisible object moves or is moved,
successful detection attempts must be made
in each end every round to keep from losing
track of it again, because physical invisibility
is not permanently negated (for that
viewer) by a successful detection attempt.
The spell remains in effect until it is
magically broken or dispelled, or until the
duration expires. The recipient of the spell
may cause damage or take damage without
negating the magic. As with other types of
invisibility, attacks against the recipient are
at -4 ?to hit? in addition to any other bonuses
or penalties that apply. The material
components of the spell are a prism and a
small mirror.
 

Mind-Control Invisibility
(Enchantment/Charm)
Level: 5
Components: V, S
Range: 0
Casting Time: 4 segments
Duration: 2 rounds/level
Saving Throw: Neg.
Area of Effect: 4? radius of caster

Explanation/Description: This spell af-
fects the minds of one character or creature
per level of the caster (all of which are cho
sen by the caster) within a 4" radius of his
location. It causes the caster (and only him)
to become visually undetectable by the
victims. No matter what means are used to
locate him, the minds of the victims will not
believe the caster is there. Note that only
creatures within 4" of the caster are so
affected; the mind control is broken if
movement takes the caster and viewer more
than 4" away from each other. The caster
can attack a character or creature affected
by the spell, and the defender can only
attempt a futile defense; shield and dexterity
adjustments are not counted on any
blow. Victims may believe some arcane
spirit or other aberration is attacking them.

All whom the caster intends to affect by
the spell are allowed a saving throw versus
spell at -2 (plus any wisdom bonus or penalty)
to escape the mind control attempt.
Dispel magic will negate the spell if successfully
cast against the level of magic at which
the mind-control invisibility was cast. Detect
charm will pick out those people under
this spell's effects.

Conclusions
Invisibility is not a single power, but is
rather a set of very different powers with
similar effects. The distinctions between the
three types are very important for an accurate
simulation of the magical effects that
occur, and add depth to the playing of the
game.

Overall, everything is subservient to fun.
This look at a very basic AD&D power was
not meant to complicate the game, but was
an attempt to understand its foundations,
and to inject an element of freshness into
the play. The new spells will, I hope,
achieve this last goal.

Invisible Problems
Dear DRAGON, 
Brian Roessler
According to the author of the article "Seeing
is believing" (issue #105), ?About 2? is how far
the invisibility extends.? If the invisibility extends
in all directions, the floor below him would be
invisible for 2? down and over at an upward
slope. Isn?t there a special ruling that he [the
author] should have made about this? If not,
invisibility is useless because when a moving
patch of invisibility saunters into a room. it
would take a really dumb monster not to know
something was amiss.
    Brian Roessler
    New Providence, N . J .
    (Dragon #108)

Dear Sirs: 
Physical invisibility, as described by ?Seeing is
believing? (#105), is caused by bending light
waves around the object so made to vanish. Such
a method would undoubtedly cause the recipient
to become temporarily blind. This is because no
light could reach the one rendered invisible.

A similar problem is reached if one considers a
substance that renders the subject perfectly and
completely transparent, to the extent of eliminating
light refraction, as in The Invisible Man by
H.G. Wells. This is because light would pass
through the retina unless one considers the Detection
of Invisibility Table (DMG p. 60) is for
determining of you notice a pair of eyeballs
floating about the room. This does not matter if
the object is inanimate or if blindness would not
normally affect it, but a PC would usually suffer
even more than the monster he is attacking.
    Erik Burch
    Stuyvesant, N.Y.
    (Dragon #108)

These and other letters we've received about 
the invisibility article demonstrate how difficult it 
can be to describe an imaginary concept in concrete 
terms.  Brian and Erik have made good, 
logical points, and the only way I can see to 
address them is to make arbitrary and pragmatic 
judgments about how to handle those aspects of 
invisibility in the play of The Game.  We encourage 
our authors not to be arbitrary and pragmatic, 
which is why problems of this sort are sometimes 
not addressed in the articles themselves.  But if I 
was in charge of your campaign, here are the 
arbitrary and pragmatic rulings I would make: 

Invisibility extends in a 2’ radius around an
invisible creature, but only affects objects in that
area that are picked up, held, worn, or carried.
Invisibility does not extend through the floor
someone is standing on, nor through a wall he
may be touching.

Physical invisibility affects the viewer’s ability
to see an invisible creature, but does not work in
reverse. The invisible creature’s eyes work normally,
enabling him to see out although others
cannot see in; compare this to a one-way mirror,
if that makes sense to you. — KM