Sensory Signature
Another characteristic of spells is their sensory signature, or just how noticeable the effects of the spell are. A lightning bolt includes a blinding flash of light and a deafening clap of thunder; clearly, it is much more noticeable than a shocking grasp or an unseen servant. Many spell effects are completely undetectable; for example, a charm person, polymorph self, or feeblemind spell may wreak all kinds of havoc with the subject, but outside observers can’t see, smell, or hear anything when the spell is cast that lets them know that magic was just employed. Sensory effects fall into (naturally) five major categories: sight, hearing, smell, touch, and taste.
Sight: Spells that create matter, project energy, or create visible changes in the subject have a visual sensory signature. Any creature close enough to see the effect will be aware of the fact that a spell has been cast.
Hearing: Most spells with visible signatures also have an audible signature as well, even if it’s a weird hum, buzz, or ZOTTT! as the magic affects its target. A few spells have particularly noticeable audible signatures, such as lightning bolt, shout, and other such deadly enchantments. Very few spells have an audible signature without some form of visual signature as well.
Smell: Enchantments such as stinking cloud and cloudkill are the obvious offenders in this category, but other spells may leave olfactory signatures behind, particularly spells that start fires. The pungent fumes of a pyrotechnics or incendiary cloud spell may easily be the first thing an observer notices, even before he sees the smoke.
Touch and Taste: Usually, if a character’s close enough to notice a spell’s effect by these methods, he’s already quite aware of the fact that magic has been used against him. However, in some cases, this might be a character’s only way to detect a spell. For example, a character who has been magically blinded and deafened would still feel the warmth of a distant fireball on his face or feel the tremors caused by a priest’s earthquake.
Strength of Sensory Signatures
All sorts of conditions may influence the obviousness of a spell; a lightning bolt may be reduced to a dim, distant flash in a deep fog, but the crack of the thunderbolt will still be quite audible! The number of creatures affected by a spell can be used as a rough measure of the strength of a sensory signature, as shown in Table 40: Sensory Signatures.
For example, a fireball normally affects a 20 foot radius, so it would be considered a huge signature detectable at a range of 500 feet under good visibility conditions. On the other hand, polymorph other affects only one target, so it would be a medium signature spotted at a range of 50 feet. Obviously, the DM has a great deal of latitude here; spells break the rules of the game, and many defy classification.
If the visibility is poor, the ranges listed above could be reduced by as much as 50 to 75 percent. However, simple darkness may not conceal spells with brilliant or fiery effects; if anything, a fireball or lightning bolt is even more visible at nighttime than it is in daylight!
Spells can usually be heard or smelled at half the range they can be seen and felt at one tenth the visibility range. The roar of a fireball normally carries for 250 feet or so, even if the blast itself is out of sight around a corner or behind a hill. A deafened character who isn’t looking at the blast can still feel the heat of the fireball from as far as 50 feet away. However, sound and smells may not propagate in a perfect circle from the spell’s targeting point—if there’s a strong wind blowing, the faint stench of a stinking cloud may be noticeable a mile or more downwind, while stone walls and large areas of still water may reflect or bounce sounds to several times their normal carrying distance.
# of Targets Affected | Area Affected | Visible at Range (Size Category) |
Self | Caster | 20’ (S) |
1 Target | 5’ sq. or 2’ rad. | 50’ (M) |
2–9 Targets | 30’ sq. or 15’ rad. | 200’ (L) |
10+ Targets | 40’ sq. or 20’ rad. | 500’ (H) |
40+ Targets | 100’ sq. or 40’ rad. | 1,000’ (G) |
Sensory Signatures by School
While each school of magic includes a variety of different spells, it’s possible to make some general observations about each school. Both priest and wizard spells of the listed type share some common sensory signatures.
Abjurations: Spells of this type fall into three loose categories—those that create barriers, those that enhance the recipient’s resistance to attack, and those that directly attack the offending creature or object. Barriers include spells such as protection from evil, minor globe of invulnerability, antimagic shell, or prismatic sphere; generally, these spells have a normal visible signature for their size, but don’t produce odd smells or sounds. Spells that enhance resistance include sanctuary, nondetection, or protection from normal missiles. These enchantments have small signatures or no discernible signatures at all. Abjurations that attack the offending creature include fire trap, repulsion, or banishment; they may include sight and sound signatures as normal for their area of effect. The following are some specific examples:
- Protection from evil: moderate visual;
- Minor globe of invulnerability: small visual;
- Banishment: small visual, small audio.
Alterations: This broad school includes spells designed to accomplish a multitude of effects. As a gross generalization, all alterations have the signatures derived from their areas of effect with a couple of notable exceptions. Alteration spells that affect other spells (the so‑called “metamagic” spells, like far reaching or Rary’s mnemonic enhancer) and spells that imbue the caster with a quality that doesn’t change his appearance (comprehend languages, fly, or water breathing, for example) usually have no signature at all. Specific examples appear below:
- Burning hands: moderate visual and audio;
- Haste: no signature at all;
- Animal growth: moderate visual and audio.
Conjurations: Most conjurations involve visual sensory signatures since people on the scene notice whatever it is that just appeared, but audio signatures are unusual. Instead, olfactory signatures—strange smells and odors— often accompany spells of this school. Also, tactile sensations such as chills, goosebumps, or nausea may come into play when doors to other dimensions are opened in the vicinity. The following are specific examples:
- Unseen servant: small audio and tactile;
- Monster summoning: moderate visual;
- Power word: small audio and tactile.
Divinations: A great number of divinations have no sensory signature at all since they impart information directly to the caster’s awareness. However, some divination spells (such as detect magic) cause the items or objects in question to glow, so that anyone nearby can see them.
Enchantments: Spells of this type that directly manipulate the subject’s mental or emotional state have no signature to speak of, but a few spells of this type that relay compulsions or orders, or affect objects instead of people (command, bind, ray of enfeeblement, snake charm, trip, or snare, to name a few examples) have normal sensory signatures as appropriate for their areas of effect.
- Charm person: no sensory signature;
- Hold person: moderate visual/tactile signature;
- Ray of enfeeblement: small visual/audio signature.
Illusions: In one sense, illusions are nothing more than sensory signatures with no reality attached to them. The central spells of this school—phantasmal force and its various improvements and refinements—are designed to create the largest “signature” possible and may easily be observed from quite a distance away. A few illusion spells work directly on the mind of the subject and have a much smaller sensory effect; these include misdirection, phantasmal killer, or eyebite. Illusions that mask or conceal something else have no true sensory signature in and of themselves; if an invisible wizard was surrounded by a glow or gained a pungent odor, the spell would be worthless!
- Phantasmal force: visual signature by area affected;
- Wraithform: small visual/tactile signature;
- Eyebite: no sensory signature.
Invocations: Without question, the school of invocation/ evocation includes the most spectacular spells available to a wizard or priest. Like it or not, a wizard who throws fireballs and lightning bolts is creating a fireworks show that people can see and hear for quite a distance away. Blinding flashes of light and deafening peals of thunder leave no doubt in the observer’s mind that magic is at work here. Here are some classic examples:
- Magic missile: moderate visual signature;
- Fireball: huge visual, moderate audio/tactile;
- Cloudkill: large visual, large olfactory.
Necromancies: While spells of this school can be extremely potent, the flash and bang of a powerful invocation isn’t found in most necromancy spells. Most necromancy spells affect only a single subject at a time. Tactile sensations such as chills, nausea, or disorientation are somewhat more common in necromancy than thunderous detonations or weird haloes of light. The following are some good examples of necromancy spells:
- Enervation: small visual/audio/tactile;
- Animate dead: moderate visual/tactile;
- Cure serious wounds: small visual/tactile.