Detect Illusion + SCS - Not working??

tedmann12

In my current playthrough I succesfully used detect illusions on the lich in the graveyard with the nether scroll to dispell his invisibility.

However, I am trying to do the guarded compound fight and I went up the stairs invisible and stood behind Sion for a long ass time detecting illusion (skill is at 80) and I keep getting the dialogue "Sion: Illusion Dispelled" but he is still invisible. Really trying to back stab this fucker because this fight is just wrecking me. Granted I am not very high level and only have a party of 4.

Anyway can someone explain why he remains invisible?

Thanks!

jmerry

Detect Illusion doesn't work on non-illusion invisibility, such as what many thieves start with in SCS. You can't reveal Ketta the first time with thief Detect Illusion; only something like the spells Detect Invisibility or True Sight will work.

However, Sion is a pure mage. His only source of invisibility is his spells. Detect Illusion should work on him. There is no good reason for him to remain invisible after that detection.

tedmann12

Weird...

Yeah Sion (and his simulacrum) both just sit there invisible after the chat reads "illusion dispelled".

jmerry

Wait, Simulacrum? SCS mages don't use that spell. None of them will ever memorize it. Do you have another mod that tweaks enemy mages?

tedmann12

Maybe it’s not his simulacrum, I just assumed it was. Theres 2 people invisible then, standing ontop of some aura. I think the same looking one that the cloak of mirroring gives.

Are you sure scs mages don’t use that? I feel like when I do Watcher’s Keep Statues fight I always battle one of the mages with his simulacrum?

jmerry

That visual effect you're noting is Spell Deflection. And that effect is visible even when the creature isn't, because the game is silly sometimes.

A complete list of BG2EE mages with clone spells (Project Image or Simulacrum) memorized, in my installation (game version 2.5, SCS version 33.7):
Elminster/"Terminsel". He has all the spells, but isn't hostile.
Korkorran (Hexxat's ToB quest). Not changed by SCS at all.
"Stannel Eibor" (Black Pits 2). Not changed by SCS at all.
At least one other mage from an EE character's quest uses a clone spell in a chain contingency. Again, that's a creature SCS doesn't touch.

All those normal mages, across two campaigns ... nope. None of them use clones. Maybe Mislead, but that's more of an advanced invisibility spell.

Another invisible creature next to Sion is pretty likely. Specifically, an invisible servant pre-summoned by Stalman. Detect Illusion won't reveal that, of course.

Aerakar

@jmerry is there a list somewhere of what thief Detect Illusion does dispel in vanilla and also with SCS installed? And what it does not?

With invisibility via spells and mirror image it is clear that it does dispel as I did this just last night fighting the Druid Grove rakshasas with 55% DI.

I assume a thief hiding via stealth will not have their stealth dispelled as it is not an illusion. But what about a thief invisible via items or potions?

jmerry

A thief's Detect Illusion skill dispels all effects with the "illusion" spell school and destroys all creatures of the "illusionary" gender within its area of effect. There is no defense.

Invisibility is almost, but not quite, always an illusion effect. It would be easier to list the exceptions than what it works on.

A thief hiding via stealth will not be revealed this way. This includes the invisibility effects many thieves get when first created. Other invisibility effects that won't go away ... the MAGE01 item some creatures like aerial servants get for initial invisibility, the "ethereal" effects certain Ascension bosses use. I can't think of anything else. In particular, if a thief drinks an invisibility potion after being revealed once, DI will reveal them this time.

VanDerBerg

Out of curiosity, besides revealing those hidden in shadows, is there any other situation where true sight is better than detect illusion? Does true sight work without breaking invisibility, like DI does?

jmerry

As a self-targeted spell without an explicit flag for it, True Sight/True Seeing does not break invisibility for the caster.
The rare cases of non-illusion invisibility are the only instance in which True Sight/True Seeing is a stronger effect than thief Detect Illusion. I'm not sure about the area of effect; subjectively, DI feels like a pretty small area, and True Seeing is definitely very large. On the flip side, the SCS component that makes Breach work on liches has what I have to consider a bug - with it, only the first round of priest True Seeing works on liches and rakshasas.

VanDerBerg

So, if their areas of effect are similar (or maybe even if they aren't), DI sounds like a more useful thing, if anything because it doesn't get blocked by SI: Divination and can also be used in no magic zones (I still have nightmares of that one encounter in SoD where you are ambushed by a horde of invisibility potion drinking thieves in a no magic zone).

There is one tweak mode that fixes True Seeing so that it has a constant effect, rather than just triggering once per round. That would make it far more useful.