Hitchhiker's Guide to the Planes
Myre grinned as the party ranger tracked the demon. He had seen this demon kill one of his friends – a foolhardy fighter – in a hellish manner. The demon had said several words and a wall of rainbow appeared and destroyed his friend in a way Myre hated to think about, but now the demon was going to feel the same pain. Myre’s group turned the corner to the demon and its lackeys. Myre repeated the words he’d heard at their last meeting. The demon laughed as he heard the beginnings of the incantation. The laugh cut off suddenly as a cone of rainbow spewed from Myre and subjected him and his minions to burns, shocks, poison, and petrification. The last Myre saw of the demon, he was turning to stone as he was banished to one of the other Planes.
As most people are aware, color has magical properties. The culmination of the research of the magical properties of color was at one point the Prismatic Wall, which creates a wall of rainbow that causes various effects to anything that passes through it.
Prismatic Spray is a reworking of the Prismatic Wall. Rather than a wall, it releases a cone of rainbow colors from the caster. The cone causes a variety of effects to every creature inside of it; sometimes an unfortunate target even suffers two different effects at the same time. Unlike the wall, Prismatic Spray can be Counterspelled, but it’s extremely difficult to do. Only a very talented sorcerer or well-versed wizard can even attempt to counter it. Prismatic Spray sends several rays of seven different colors into a cone in front of the caster, affecting the creatures in the cone in different ways.
It is theorized that Prismatic Wall was the greatest work of a great wizard. Prismatic Spray is the effect of another wizard taking the theory and playing with it. After the discovery of a Prismatic Wall in an ancient battleground, a few wizards took the spell apart and learned the theory behind it. Through their combined efforts, they figured out how to shoot the effects of the wall straight out from themselves. Better yet, casting the spell in this way actually requires slightly less power, making it more accessible as well.
Each color created in the casting of Prismatic Spray sends out a ray and affects different targets in the cone. Some targets are even affected by two different rays at the same time.
Learning the Spell
Prismatic Spray is a rather difficult spell to learn. The spell is easiest to learn if you already understand the theory behind Prismatic Wall, but the road to learning the the spell can also begin with Color Spray, an illusion spell that incapacitates creatures with the powers of color. However, instead of focusing on wall spells, the learner follows up with spells such as Burning Hands or Conjure Barrage that create a cone effect, especially the creation of multiple objects in the latter.
Casting Prismatic Spray requires an incantation of several specific words related to each color in the spray in a quick succession. It is suggested that the order of the incantation in each casting of the spell be different because a wizard who’s grown too comfortable and says one of the words incorrectly risks the spell falling apart and blowing back on himself. The hand movements are similar to that of Prismatic Wall, but instead shapes the spell into a cone.
Red: The first color is created by a word spoken in the tongue of the Efreeti and is the easiest of the colors to create. Creatures affected by the Red rays are burned terribly.
Orange: The second color requires a word “donated” by the Duergar. Orange rays draw from the acidic creatures of the Plane of Earth, causing creatures in the cone to literally have acid eat away at their skin.
Yellow: A word of the Drow must be spoken to send out the yellow ray. Creatures affected by the yellow ray are shocked by a series of lightning strikes.
Green: Speaking the name of an infamous green dragon creates the green ray. This ray evokes the poisonous breath of the dragon, causing afflicted targets to become extremely poisoned.
Blue: An Illithidic word creates the Blue ray. The blue ray channels the coldness of the Illithid’s society into a frigid ray.
Indigo: The word for this ray was taken from the Medusae. This ray slowly turns its targets into stone statues.
Violet: The seventh and final color is the greatest of the Prismatic Spray. The final part of the incantation is not from any language known to sentient life, but rather two syllables stolen from the gods themselves. This ray blinds its targets, and several of the poor blinded creatures are transported to an entirely different plane of existence altogether.
There are some advantages to using Prismatic Spray rather than Prismatic Wall. While the wall is relatively safe to cast, the order of the incantation and hand movements for the spray is actively different every time instead of being catastrophic when out of order. However, the blow back is much worse if the spell is done incorrectly. Due to the fact that the spell was made from the reverse engineering of Prismatic Wall, the spell will not only fall in on itself, but it will also collapse on top of the caster. Some inexperienced wizards who try to cast this spell have had all 7 color rays fall onto them, immediately destroying them. Usually, the bodies are teleported to another Plane and never recovered.
While uses of Prismatic Spray on different Planes are not well documented, a wizard who once visited Barovia in the Shadowfell claims the the colors of the Prismatic Spray were grayscale when cast in the Shadowfell, but the effects were the same as if it were the Material Plane, so there are no survivors to back up his claim. It is also theorized that casting the spell on one of the Inner Planes could strengthen the ray associated with that plane, such as the Red ray on the Plane of Fire.