Q: Is it possible to use the major image spell to emulate the effects of other spells? Most of us are aware of the three different types of illusions and that things like major image shouldn’t be able to deal real physical damage since that’s the realm of shadow spells, but we’re interested in your advice on just what kinds of effects can be done with major image. Would an illusion of a hail of arrows from an unseen source cause those who failed their saves to believe themselves pierced by multitudes of arrows and have them collapse in unconsciousness? What if you created a swarm of fireballs (as with the meteor swarm spell) through major image?
You cannot use a figment spell such as major image to produce any real effects. Damage—even nonlethal damage—is a real effect. You can use major image to create an illusory hail of arrows, but those arrows cannot harm anything. They cannot even stick into anything; though you can make them look like they’re sticking into something…
Assuming the spellcaster knows what a hail of real arrows looks like (and I expect that most adventurers do), the hail of illusory arrows from major image looks, sounds, and even smells like the real thing. Creatures can hear them zipping through the air and hear them striking home. Anyone caught in the volley likely notices the arrows aren’t dealing any damage. In most cases, that provides incontrovertible proof the illusion isn’t real.
You can adjust for the circumstances, however. For example, heavily armored creatures might believe they’re protected from the “deadly” arrows. Even in such a case, I recommend that being caught in the hail of illusory arrows count as interacting with the illusion, so the heavily armored creatures should gain Will saves to disbelieve the illusion.
The major image caster can make the area where the illusory hail of arrows struck look like it’s strewn with spent arrows. This lasts only for as long as the spell lasts.
If you make the arrows look like they’ve turned something into a pincushion and that something is mobile, keep in mind the illusory arrows remain only so long as they remain with the major image spell’s area, which the caster must choose at the time of casting. The spell’s area is not mobile.
Figments are better at fooling creatures. You could use major image to create a hail of arrows that neatly brackets a creature or group, landing just a hair’s breadth away and thrumming with (apparently) deadly potential. In such a situation, creatures should not gain a saving throw against the illusion unless they take a moment to examine the arrows (at least a move action). Since major image doesn’t have a tactile element, trying to touch the arrows reveals the illusion. Just looking them over merits a saving throw for disbelief.
An illusory meteor swarm created with major image would work much like a hail of illusory arrows. The swarm looks, sounds, and smells like the real thing—assuming the caster knows what a meteor swarm looks, sounds, and smells like, which might not be the case. You might want the caster to attempt a Spellcraft or Knowledge (arcana) check to duplicate the actual spell. Skip the check if the major image caster actually knows how to cast the spell being mimicked. If the major image caster does not know how to cast the mimicked spell but has witnessed someone cast the spell, I recommend a skill DC of 15 plus the spell level.
If the major image caster has never witnessed the spell being cast, make the DC 20 plus the spell level. If the check succeeds, the major image caster creates a convincing image. If the check fails, the major image caster creates a flawed image and saving throws to disbelieve the image gain a bonus equal to the failed check result subtracted from the DC.
For example, a spellcaster who has never seen meteor swarm cast tries to create an image of one. The skill DC is 29. If the caster’s check result is 21, Will saves to disbelieve the image gain a +8 bonus. You can use a similar procedure whenever someone tries to make an image of an unfamiliar force or object. Use the appropriate Knowledge skill.
No matter how accurate a figment of a meteor swarm is, it cannot damage or burn anything. The major image caster can make the area where the illusory swarm struck look and smell burned, though only for the duration of the spell.