This was originally published in April of 2014. Hack & Slash compendium III is available in print in from Lulu and in PDF from DTRPG, and contains this series of articles on illusions, as well as many other class ideas.
A FLAILSNAILS and Campaign guide
Illusionists are the most powerful class in the game bar-none, but you won't play them because your Dungeon Master will screw you.
Well, it's 2014, and it's past time for illusions to be screwing over players and dungeon masters. It's powerful, but it's not nearly powerful enough to unbalance a campaign, any more than any other kind of wizard. Illusionists have their power limited by locality. An illusion has to be seen, after all, to be believed. And in order to be one, you're giving up the fireball/teleport/ real ultimate power path of the traditional mage.
Shouldn't you actually be good at illusions?
The cardinal rule of the illusionist is this: An Illusionist can be more flexible, but not more powerful than a Magic-User of his level.
There are literally hundreds of spells to use as guidelines for power levels. What the illusionist gains in battlefield control and target influence, they give up in utility and raw damage. ("I can summon an illusionary ladder you can't climb?")
An Overview of Illusionist Magic
Example Spells: Phantasmal Force, Audible Glamer, Spectral Force
These use light and force to trick the senses. They may create sensations of light, heat, sound, or touch. However, they are not real. It is like a hologram. They are images and cannot be touched. They cannot change the nature of something -- A real sound cannot be altered, though a figment could make noise.
In order to produce a figment you must be familiar with the creature, object, sound or whatever you are producing. Familiar means you've experienced it with the sense you're trying to trick in real life.
Being unreal, means that they cannot damage creatures, support weight, feed people, or various other effects. This does not mean people cannot believe they are hurt, but any damage they think they have taken is simply subdual damage.
Example Spells: Change Self, Invisibility
Glamours use light and force to affect an object, making it somehow look, feel, or taste differently. Otherwise it works as a figment that appears to change the nature of an object. Like figments, they are not real. It changes appearance and sensation only.
Example Spells: Color Spray, Hypnotic Pattern
Patterns create visual displays of light and color, but these directly affect the mind. Belief is a non-factor in these spells -- they are handled much like charms.
Example Spells: Fear, Phantasmal Killer
A phantasm creates an illusion that exists only in the mind of a target. It is a magical effect targeting their mind and is not perceivable to anyone in the real world, other than by the effects it has.
Example Spells: Shadow Monsters, Shadow Magic
These spells are not entirely illusions, but are partially real! They have real effects just like normal magic user spells, as noted in their description.
Concentrating: Some spells last as long as you concentrate on them. This prevents you from casting spells or making attacks [Standard Actions], but allows you to move or take other actions [Move Actions].
Adjudicating Illusions (Figments and Glamours)
Most illusions are simple to adjudicate. Shadow spells, phantasms, patterns, and more traditional magics all have their results spelled out in the spell.
But the pièce de résistance of the illusionist is the Figment and the Glamour: The spells most open to creativity and most likely to be shut down by the Dungeon Master. What is a fair way to adjudicate these spells? (Figments below refers to figments and glamours in every case). Super simple guidelines and rules follow:
Figments look real: Any creature (player or monster) that can perceive a figment or glamour receives no saving throw and believes that it's real and acts accordingly. If a player casts a phantasmal force of a 20' x 20' pit that's 20' deep in a room, and then a bunch of hobgoblins enter the room, each hobgoblin will treat the pit as if it is real.
Figments can't do real damage: If one of those hobgoblins is knocked into the "pit", that hobgoblin would receive a saving throw versus spells to disbelieve the illusion. On a successful save they would disbelieve the illusion. On a failed save, they would take 2d6 subdual damage from the "fall" and then realize after that the pit was an illusion, because even though they can see it, they are still clearly lying on the 'floor' level.
Figments continue to exist after being disbelieved: All the other hobgoblins see the hobgoblin "fall" and just hit the floor, they don't need a saving throw to disbelieve. At this point, every hobgoblin can clearly tell that the pit is an illusion. The figment is still visible as a translucent outline to those that know it is false.
Often people might descend into arguments like "The hobgoblins were fighting! They wouldn't see!" or trying to get very specific about the fictional reality. The important fact is we are playing a game. Figment spells are usually low level (generally 1-3) and exist primarily for the purpose of battlefield influence and control or trickery. Generally they are not expected to last much beyond their first interaction. The trick is in creating a situation where their influence won't be tested and will continue to assist the party.
Figments and Glamours inhibit behavior: If the figment is believed, then the subject will act as if the figment is real. If there is some question about taking a risk versus an illusion a morale roll is a good method for adjudicating the subject behavior. This is especially useful because this method means that undead and constructs are generally unlikely to let illusions modify their behavior.
Figments are not mind control: If a figment does not successfully duplicate the effects of its representation, then it is disbelieved without a saving throw. I can use Phantasmal Force to create the illusion of a wall of fire across the room, but anyone approaching within 10' will instantly disbelieve the illusion because there is no thermal component. Creating an illusion of a pit falling open in front of a monster with no sound? Instant disbelief for everyone in hearing range of the pit. Pits don't fall open with a clatter or bang.
Figments can trick the target: You can create an illusion of a wall over a hallway, and unless touched the illusion will be believed. If your illusion of fire is a Spectral Force, then getting close enough to feel the heat forces a save, not automatic disbelief. On a failed save, passing through the fire causes subdual damage from the imagined pain. If you fail a save versus a figment, you believe it, until you are provided new evidence to the contrary or told that it's an illusion, both forcing new saves.
Figments are expected follow normal rules: A Spectral Force of a fire subject to a deluge of water will be automatically disbelieved if the fire continues to burn.
Figments cannot duplicate spells: You cannot create a figment of a 'fireball', for several reasons -- primarily because fireball is instantaneous, consisting of heat and force (which figments cannot produce). Figments and glamours produce primarily images, along with sounds, smells and temperature changes. The illusionists ability to mimic magic user spells are covered by the shadow spells. Attempting to use a Figment to do so will fail.
Interacting with Figments provides a save: Whenever you have an opportunity or chance to interact with a figment a saving throw is made. This saving throw may be modified by a number of factors, but is usually only modified from -4 to +4. Factors that may modify a save include:
- +1 for every hit die the subject has higher than the level of the illusionist
- -1 for every level the illusionist is higher than the subject
- +4 (or more) if the illusionist is not familiar at all with the image produced by his illusion
- -1 to -4 for the degree of familiarity the illusionist has with the image produced by the illusion
- No modifier at all if the illusion is familiar (i.e. has seen or studied for a turn) the subject of the figment.
- Situational modifiers that may increase or decrease the likely-hood that the illusion is believed.
- Dumb or gullible creatures are more likely to believe illusions. Smart, genius, canny, or skeptical individuals may be less likely to believe illusions, though they are not immune. (reference wisdom defense bonus)
Illusionists are skilled at producing figments: This means that, in general, reasons that the DM might think of that the illusion won't work outright are also things that the illusionist is aware of. The illusionist is assumed to be skilled. When the illusion is being described, the players and DM should discuss any obvious problems or issues with the illusion. The object is not to 'trick', stymie, or remove the power of the illusionist -- the goal is to understand what is being produced so it can be adjudicated fairly.
These should provide clear guidelines for adjudicating illusions fairly.