How are prebuffs chosen?

[gatperdut]

I'm curious about how the buffs cast in advance for arcane and divine casters work. In Tactical difficulty, for example, the spells are elligible if the duration is 3 rounds/level or more. 2 rounds/level or more for Hardcore. And 1 round/level or more for Insane.

But take Mulahey - he's a 7th level cleric and in my installation he has memorized, among others:

* armor or faith: 3 + 1/level rounds

* spiritual hammer: 3 + 1/level rounds

* remove fear: 1 hour, or 50 rounds

So I confront him and...

* tactical: precasts nothing.

* hardcore & insane: precasts spiritual hammer & armor of faith.

Why though? Neither spiritual hammer nor armor of faith meet the "requirements" for tactical/hardcore, and remove fear is ignored in all 3 even with its long duration.

Is my installation broken? Is it because he's not expecting the party so he's a special case? Both approaches to confronting him (directly, or pretending to have been sent by Tazok) yielded the same prebuffs (or lack thereof).

[gatperdut]

Also, in line with this, Ctrl Q'ing some enemy mages shows that some have unused spell slots - the guy in the Nashkell carnival threatening to kill the woman had his single fourth level slot empty. Is this intentional?

[Palanthis]

In Tactical difficulty for pre-buffing, spells are only cast if their duration is "1 turn or more". So Mulahey won't cast armor of faith or spiritual hammer, except on hardcore pre-buffing, where indeed clerics can pre-buff with spells with a minimal duration of 3 rounds or more. That's what you described and it seems to work as intended.

The duration of 3 rounds for Tactical is only when mages " appear in sight of the party" which means, if i'm not mistaken, when they teleport in front of your party and basically ambush you (like the Cowled Wizards in Athkathla when you use magic outdoors). Mulahey is not ambushing you : instead, you are the ones who take him by surprise.

Also I'm not sure about the SCS wording "3 rounds / level" : in my experience, "3 rounds +1 / level" are included in this category. So it's working as intended, if i'm not wrong about the way it's supposed to work. I might be wrong here.

I suspect "remove fear" is not a buffing spell for the AI. Even though you can use it like a buff, i think the AI use it as the spells description implies : as a way to remove fear from allies. That's why it's not cast as pre-buff, or so i think. Maybe this could be changed indeed since it can work as a buff for you, so the AI should be able to use it as a buff as well.

Edited June 9, 2022 by Palanthis

[jmerry]

Mechanically, the scripts look for the designated buff spells in memorization. If they apply, the AI applies the "previously cast" clone of the spell and removes a copy of the original spell. For spells with a duration of more than eight hours, the AI applies the "previously cast" clone without checking for whether the spell is actually memorized or removing a memorized spell. In the case of summoning spells, there's no separate version of the spell; the AI just instantly applies it.

There is a "previously cast" version of Remove Fear. Here's a list of the spells which have precast versions from my (v33/2.5/no IWD) install:

Bless, Remove Fear, Shillelagh, Armor of Faith, Barkskin, Flame Blade, Spiritual Hammer, Draw Upon Holy Might, Protection from Fire, Animal Summoning 1, Free Action, Defensive Harmony, Death Ward, Holy Power, Animal Summoning 2, Iron Skins, Chaotic Commands, Magic Resistance, Righteous Magic, Blade Barrier, Shield of the Archons, Regeneration, Armor, Shield, Invisibility, Mirror Image, Haste, Non-Detection, Protection From Normal Missiles, Ghost Armor, Minor Spell Deflection, Protection From Fire, Protection From Cold, Fire Shield (Blue), Improved Invisibility, Minor Globe of Invulnerability, Stoneskin, Spirit Armor, Fire Shield (Red), Shadow Door, Protection From Electricity, Protection From Acid, Phantom Blade, Spell Shield, Minor Spell Turning, Immunity: Abjuration, Immunity: Divination, Globe of Invulnerability, Protection From Magic Energy, Improved Haste, Spell Deflection, Spell Turning, Protection From The Elements, Improved Chaos Shield, Spell Trap, Energy Blades, Energy Blades, Globe of Blades, Aura of Flaming Death, Storm Shield.

The issue here is that this isn't translated to the actual scripts. Remove Fear isn't being used as a prebuff because the SSL scripts that build the priest AIs don't include it (priest prebuff stuff is in priest/ssl/prep).

[DavidW]

The actual list of 'cast previously' spells is in caster_shared/prebuff.2da.

I can see the case for scripts treating remove fear as a prebuff. (But yes, conceptually I was thinking of it as an in-battle counterspell.)