100-precision area-effect spell targeting

[vfb]

There was a bunch of discussion in an EA Agartha guide about whether 100-precision area-effect spells can miss their target. In order to keep the Agartha guide on topic, I'd like to move that discussion here please.

I made a self-bless mod long ago because I was tired of my Dai Onis missing when they did their bless, but looking at some recent debug logs, I see the Dai Onis were actually targeting the square with their batsum wolves (which as thejeff says is a bug in itself).

Does anyone have a save file or a debug log where they have a single unit casting bless on themself, but missing, and no other friendly units are in the battle?

[chrispedersen]

Hmmm...

I wonder vfb... there used to be a bug where the armor of virtue would 'miss' if the wearer moved.

I wonder if the dai oni's are somehow missing because of the dom summon.

If you remove the battle summon - does the dai oni continue to miss. I bet... not.

[vfb]

TheDemon and Sombre both said that they think Bless can miss a self-cast by a solo unit, even for non-DaiOnis, for example Harbingers miss themselves, and Dis, and Yaksha.

But in my limited tests (just 20), I could not get a solo H1 to miss. MaxWilson says he thinks the miss rate for a solo unit is 1%, so I'm guessing I'd need 300 runs of a test without failure to be confident that it always hits.

[thejeff]

I was playing around with Jotun Jarls to test this and though I haven't yet got a solo Jarl to miss I did get one to cast a bless that only hit already blessed Woodsmen.

It looks to me like it might be an artifact of the AI determines which spell to cast and where.
It essentially runs multiple tries and picks the one with the best results, usually most damage, possibly most units blessed in this case. Then when it actually casts the spell it rolls all the dice again so the results can be different.
It targets units within range and rather than checking whether that unit can be blessed it just sees if casting bless on that unit results in units getting blessed. With the Dai Oni's wolf or my already blessed Woodsman, I suspect the test case hit a sacred unit, so it went ahead and cast on that target. With different random splash it missed all the unblessed sacreds.

This isn't necessarily a bad thing. If you had sacreds clustered around a non-sacred, targeting the non-sacred might actually get you more blessings.

It doesn't explain my strong memories of Jarls not blessing themselves, but I could be wrong. That may have only happened on defense when there was some PD around.

[chrispedersen]

I see blessings miss *all* the time, as mictlan, as ea agartha.

I agree it tries to maximize friendly damage. I believe this can mean it centers on a space with no creature - or with a non sacred.

I believe the template that takes effect thereafter also allows things to be missed.


Some interesting cases to test.

a. High HP and Low HP unit .. exactly 10 squares apart. What happens over multiple blessing.

b-e High HP and Low hp... 8, 4, 2 1 square apart.

f. Repeat A with 50 hip and 2x25
g. Repeat b-e.

[vfb]

Thanks, thejeff! That sounds like a reasonable explanation.

chrispedersen, I know the area effect is random and can miss units. What I'm trying to determine is if the targeted square is always hit as part of the blast. I think it's always hit (as the first blastsqr affected), so I believe a solo unit should always manage to bless itself.

If someone can provide a save game or debug log proving otherwise, I will change my beliefs immediately.

[TheDemon]

I'll try my best to reproduce solo self-bless failures. Usually it happens when I'm testing a thug strat, or simulating a solo battle, so in other words I run the same or similar battle dozens or hundreds of times. I may of course be misremembering, but I think I should be able to reproduce at least one case.

[vfb]

Thanks! I appreciate the effort.

[Lingchih]

Running tests with Niefel Jarls, for an an upcoming MP game, each with one sacred Niefel giant bodyguard, placed right on top of the Jarl. Seems like both get blessed about 80% of the time. There's enough of a miss issue though, that I usually script two blesses.

[vfb]

But a Niefel Jarl is size 6, so they can't fit in one square. Have you ever seen neither unit get blessed? I'm sure the spell will either target the Jarl or his bodyguard, the spell will hit the target, and that target square will get blasted by the bless.