Persistent image.

[Sepulchrave II]

The scope of this spell is less than crystal clear.

Persistent image is based off of silent image, which may create the illusion of 'an object, creature or force' (PHB, p. 279). In the explanatory text of persistent image, an example is given of an illusion of several orcs fighting. What's going on here? Just how much can you do with this spell?

 

[Viashimo]

You can't get it to react or interact with outside forces(ie, another intelligent creature), unless it's part of the script you set up when you cast it. You can use "visual, auditory, olfactory and thermal components."
It's quite a versatile spell, so you can do a fairly large amount of stuff with it.

 

[Someone]

If you ignore the examples (not only in the spell, but in other sources, like complete arcane IIRC) and go with the RAW you can create the illusion of only 1 thing, wich is quite limiting, and actually doesn´t clarify anything. Can you create the illusion of a a fountain splashing water, or someone bleeding? A bundle of rocks? A small hill with some grass? If you create the illusion of a person, must that person be naked? and if you rule you can do it, can said person get his clothes off and leave them on the floor? IMO, a strict interpretation of the rules make the spell near useless. Personally, based on the examples, I rule that the illusion spells can create a group of closedly related things that have to fit the volume limitation set by the spell. A squad of fighters would be fine, or a shower of sparks, but not both.

 

[azhrei_fje]

Hmm. How about an illusion of a wall of force (since that fits the "or force" part of the spell description).

Would you say that casting such an illusion would stop a pursuer because they'd hit the wall? Normally, a wall of force is invisible; so since the pursuer can't see it, they just run right through it, right? Or when they would hit it, they get a save for interacting with it, and then figure out whether they run right through it or not?

Double-hmm...

 

[Gez]

First, the SRD entry:

Persistent Image

Illusion (Figment)
Level: Brd 5, Sor/Wiz 5
Duration: 1 min./level (D)

This spell functions like silent image, except that the figment includes visual, auditory, olfactory, and thermal components, and the figment follows a script determined by you. The figment follows that script without your having to concentrate on it. The illusion can include intelligible speech if you wish.
Material Component

A bit of fleece and several grains of sand.

Silent Image
Illusion (Figment)
Level: Brd 1, Sor/Wiz 1
Components: V, S, F
Casting Time: 1 standard action
Range: Long (400 ft. + 40 ft./level)
Effect: Visual figment that cannot extend beyond four 10-ft. cubes + one 10-ft. cube/level (S)
Duration: Concentration
Saving Throw: Will disbelief (if interacted with)
Spell Resistance: No

This spell creates the visual illusion of an object, creature, or force, as visualized by you. The illusion does not create sound, smell, texture, or temperature. You can move the image within the limits of the size of the effect.
Focus

A bit of fleece.​

So, the rules are very clear. You can create the image of an object (e.g., a pie), a creature (e.g., an orc) or a force. I'm not sure what they mean by "a force", a manifestation of energy? Forces are usually not seen, but felt. Could you create the illusion of a reverse gravity field? With people in the zone feeling like they're falling toward the sky, while keeping their feet on the ground. (Woah... Trippy!)

OK, so you can create the illusion of a creature. You just have to be creative with the creature you choose. Instead of creating the image of an orc, create the image of the creature known as "orc mob" (see the upcoming DMG2 for the mob type, but in short, it's like swarm for bigger creatures).

(PS: More seriously, I'd consider as a house-rule that the important parameter is « Visual figment that cannot extend beyond four 10-ft. cubes + one 10-ft. cube/level (S) ». As long as you keep within that parameter, I'd let someone create the illusion of one thing/level instead. So a wizard casting persistent image would be able to show nine or more orcs fighting each others.)