One bit required a network of circular rooms that looked perfectly identical, so that intruders could not, for example, mark trapped locations (at one point, a trap would send intruders back to the first room, so they'd be confused). I figured this called for some imaginem. But how to ensure that? I figure adding 1 magnitude for moving images, as well as one more for intricacy would probably fit the bill, but I doubt myself, so I'm calling upon your collective wisdom.
Have the identical illusion in each room be recast either periodically, or on a trigger like touching a wall?
That would work with enchanted items causing the illusions - but people investigating the room might look through simple repeat illusions in the end.
A spellcaster controlling the illusion by concentrating can also restore it, or adapt it to changes like that stick brought in and now pointing to a trap at the wall.
Moving illusions are either preprogrammed or controlled by a caster. The former are quite limited.
What it would be is that, no matter what happened, all the species of the room would revert to their "pristine" state. Of course, you could still use people as markers, but what's a poor maga to do?
This you would have first to define for your saga and the room. Which light, which shadows, which positions of objects, images in mirrors and so on are 'pristine', and then how to reset all images to that state without touching the changes of the underlying objects. Would all beings in a room turn invisible on 'reset'?
That could be a powerful ReIm spell, which might look very unnatural and disconcerting to onlookers in the room and give the illusion away soon.
That's not a bother. But, if it's just a CrIm being imposed over the "real" species of the room? I mean, if you've got a real stone floor, with the illusion of a stone floor cast on it, whap happens if someone puts paint on the floor. Would it be visible through the illusion?
I think it all boils down to this: can an illusory wall hide what's behind it? and the same goes for olfactive and tactile species
You don't worry what happens, if somebody puts an object onto the floor? Wouldn't your illusion have to cover that as well, if you wish to prevent traps getting marked?
Also note, that
are tricky. Masking those emanating from an object does not prevent that object from tripping people walking over it, or otherwise affecting them.
Without poo-pooing your suggedtions, if the trap will transport the PCs anyway, why not have each room transport anything not present at the casting of the spell to another room? You could have this "programmed" to a set rotation. So then, when the PC is transported back to room 1, the stuff they left there to mark it is transported to room 2 (or whatever).
You would probably also want an Imaginem component, as you say, to refresh the image so that PCs can't just alter or damage parts of the room itself to mark it.
