Slaughter within an illusionary area (or: Screen, a nightmare spell?)

[Dark Dragon]

Hi folks,

yesterday session was quite funny, but also with somewhat unexpected ideas...

Long story short: The party (all 5 PCs are at level 18) wants to occupy two important bridges to allow an allied army an easy march towards a hostile city. These bridges are about 3 and 6 km east to the city. The city has at least ten capable wizards for defense, so the PCs want to take the bridges without being noticed by the wizards until the army has marched through.

One of our party wizards had the idea to cast Screen on the first bridge, creating an illusion that duplicates the bridge, the 25 guards, and installations for defense (trenches, wooden walls). The party members positioned themselves under an Invisibility Sphere, the wizard then cast Screen, Will save DC is 27...The PCs attacked according to their planned strategy (all PCs succeeded their saves against the illusion) and slaughtered the 25 guards within two rounds. No alarm was given, no guard (most were fighters of level 3 to 5) escaped.

Same happened to the 60 troops at the second bridge, although fighting lasted for about 5 or 6 rounds, because some guards were positioned on two small towers close to the bridge and the party wizards decided to use non-flashy spells to bring the soldiers down.

I adjusted the Will save for the guards each round, giving them a +1 bonus for each following round, or a +4 bonus (and an additional save roll) when they were attacked (by a spell effect or in melee combat). It didn't help them much, although 6 guards surrendered when they succeeded in disbelieving the illusion (seeing most of their comrades dead and facing two large silver dragons (the party druid and a wizard had cast Shapechange) in melee range).

I was wondering about the power of Screen, granting the effects of an improved invisibility, negating any combat noise and foiling Scry attempts for 24 hours.
Any ideas how to handle NPCs being attacked under the effects of an illusion? Have you made similar experiences with the Screen spell? Ideas to prevent extensive use of the spell?

 

[Nifft]

As written, Screen only fools Scrying attempts and outside observation. "Even entering the area does not dispel the illusion..." implies that you need to have been outside the illusion when it was cast. I'd NOT allow it to fool the senses of those within the area when it's cast. I'm not sure if those in the area should immediately know that there's an illusion or not -- they could see nothing, or they could see the illusion (but automatically disbelieve it).

-- N

 

[Dark Dragon]

As written, Screen only fools Scrying attempts and outside observation. "Even entering the area does not dispel the illusion..." implies that you need to have been outside the illusion when it was cast. I'd NOT allow it to fool the senses of those within the area when it's cast. I'm not sure if those in the area should immediately know that there's an illusion or not -- they could see nothing, or they could see the illusion (but automatically disbelieve it).

-- N

Screen
Illusion (Glamer)
Level: Sor/Wiz 8, Trickery 7
Components: V, S
Casting Time: 10 minutes
Range: Close (25 ft. + 5 ft./2 levels)
Area: 30-ft. cube/level (S)
Duration: 24 hours
Saving Throw: None or Will disbelief (if interacted with); see text
Spell Resistance: No
This spell combines several elements to create a powerful protection from scrying and direct observation. When casting the spell, you dictate what will and will not be observed in the spell’s area. The illusion created must be stated in general terms. Once the conditions are set, they cannot be changed.
Attempts to scry the area automatically detect the image stated by you with no save allowed. Sight and sound are appropriate to the illusion created.
Direct observation may allow a save (as per a normal illusion), if there is cause to disbelieve what is seen. Even entering the area does not cancel the illusion or necessarily allow a save, assuming that hidden beings take care to stay out of the way of those affected by the illusion.

Hmm, following the rules, there is a save if you interact with an illusion, no matter if the PC enters an illusionary area or the illusion does something with the PC.

The last sentence states that beings could be indeed affected when entering the area and even ignore those who are unaffected by the spell.