Spells with random effects

[Magus]

I'm looking into spells with random effects. In particular, the attached one is "random spell I" from wild mage additions. In my installation, it seems to fire every single spell possible, instead of only one, as it's supposed to. I checked, and I don't see anything wrong with it. Did I miss something?

 

By the way, I found that IESDP uses rather poor wording when describing Feature Block's "probability" fields. They aren't really probablilities, but rather the boundaries of an interval of values in 1-100 (or, 0-99) range.

 

wm_rnd.spl.zip

[Jarno Mikkola]

Well it should cast only one of the spells as a result of the whole thing... so if there's 5-50 spells going off at the same time, then something is horribly wrong, but otherwise it by my eyes should be ok. So what exactly does it do in your game ? Yeah, the wording is kinda tricky to set in stone for everything possible.

[CamDawg]

This sounds like the bug we had in Fixpack with the Friends spell. We split it to have 25% chance each for four possible durations but certain players would get double/triple/etc. effects. I think we eventually determined it was the auto-pause on spell cast option, or some other gameplay option. Basically the engine rolled d100 for effects, applied one, then re-rolled and applied again. I can't seem to find the thread at the moment though.

[Magus]

This sounds like the bug we had in Fixpack with the Friends spell. We split it to have 25% chance each for four possible durations but certain players would get double/triple/etc. effects. I think we eventually determined it was the auto-pause on spell cast option, or some other gameplay option. Basically the engine rolled d100 for effects, applied one, then re-rolled and applied again. I can't seem to find the thread at the moment though.

This one? It doesn't seem to have anything said about game options.

Also, I disabled all autopause and tried, the result is still the same.

 

But this implies that spells/items like Sphere of Chaos are inherently broken and can't be fixed? Well, it's hard to say about SoC, since it's area effect, but at least Wand of Wonder seems to work fine for me.

[Mike1072]

I remember reading that thread when it was new.

[Demivrgvs]

When I tested it ages ago for SR my results were odd. On one hand they seemed to indicate that each % chance is rolled separately (e.g. if you have 0-50 and 51-100 you have 50% chance for each to trigger, but you may also get both - albeit that doesn't seem to happen 25% of times like math would tell me), otoh multiple effects with the same interval (e.g. all effects with 0-50) always trigger simultaneously which would seem to implicate the chance isn't rolled for each effect but somehow for each interval.

 

Within SR I just live with that, and the description of Chromatic Orb, Prismatic Sphere, (Sphere of) Chaos, etc. explicitly mention that you can get struck by multiple colors, rays, effects, etc.

[Magus]

Perhaps @CamDawg could check the code and say what's really really going on there?

 

In any case, the particular spell that I attached doesn't even have any random element - it just fires everything, always. I find that even more strange.

[Jarno Mikkola]

In any case, the particular spell that I attached doesn't even have any random element - it just fires everything, always. I find that even more strange.

Sorry, but unless you have something that gives you a +97 luck bonus, I cannot think a way the spell would launch all the 50 effects at the same time. As that could by default allow the random roll fill in all the effect fields.

[Magus]

So no answer? I see.

[lynx]

I didn't bother to check what ranges you set in the spell, but just an addendum to what was already said: yes, the random roll is the same for the whole effect block and can propagate even further in some opcodes. One couldn't have alternating effects otherwise (think summoning with x% chance to summon more).

[Magus]

Damn, this gets even stranger. I discovered that my initial results - getting ALL effects at once - are caused by using a container as a target (which I did to avoid too much ruckus). When casting on a creature, I get same result as @Demivrgvs: one effect most of the time, and a few effects rarely. But if targeting a container, they all fire.

What's more, they fire in improper way. All effects in this particular spell are "cast spell on target". They are supposed to be cast instantly. Instead, they're cast normally, but without interruption, as per improved alacrity.

[Avenger]

If containers as a target work differently, then you found a bug and a very good explanation.

 

Btw, containers are not a very good target, they take only 4-5 opcodes and ignore the rest.