segments of effect of area attack spells

[lortas]

Some times I get unsure who area effects/attacks works in Earthdawn.

For example if a character cast a fireball or blizzard sphere in a situation shown in this picture:

Effect segments: red, green, yellow, cyan, blue, pink

circlesegments.png (10.26 KiB) Viewed 6076 times

With the assumption that the black bars are massive non magic stone walls which are high enough. In which segments (red, green, yellow, cyan, pink, blue) a character is effected off the area attack and in which sections a character is not effected? Is there a different between the multiple area attacks (eg. fireball vs. blizzard sphere)?

[arma]

Things to consider on a per spell basis:
1) targeting requires sight, in case of something like fireball you couldn't target someone on the opposite side of the wall (this usually solves all your problems)
2) spells that create physical effects follow the laws of physics to some extent (physical vs. mystic armor), and see point 4
3) the earth isn't flat (in case of medium height walls or somesuch - also there is Cover), aka point 3D (many spells could be placed in the air)
4) spells that extend their AoE "from center" actually may expand, it's not an entire area that suddenly becomes subject to the spell. non-physical ones that count targets individually, even in an area, will home in.
5) use common sense. It's like a grenade exploding. What effect does a wall have on that? What effect does it have if it's a gas grenade? etc..

[Telarus_KSC]

I agree. Make sure your spell isn't a "name targets within line of sight" thing (like fire-ball, which uses this to get around the D&D fireball volume problem).

Apart from that, use the Cover rules to your advantage (they apply to Spell Defense as well). In this way, certain characters within the area of effect won't be effected if they have adequate cover. If, for example, the caster was standing off the image to the top left and had no way to target around/through the cover, and the spell was a "expand to fill a sphere" deal.. then yellow would have partial cover (+2 SD), cyan would have full cover (+4 SD), and the others would have Complete cover (unaffected).

If the bonus to SD brings the SD above the Effect Tests, that character is unaffected.

[lortas]

It seems I was a little imprecise in my picture. So I updated the picture by inserting centre of AoE and cater position.

Of course, in a 3D scenario with a limited high for the walls, it may be possible to place the centre of the AeE to reach all segments. But that was not by point. I choose this “simple” 2D-example to get a better understanding how area spells work in Earthdawn.

If I have understood arma right, there is no general rule and it depends on the nature of the effect/spell.

So let take fireball and blizzard sphere as examples.

Fireball: Only chars within the red segment can be effected?

Blizzard Sphere: Only chars within the green segment will be safe?

But I also like the idea for partial cover and full cover.

Are there spells which could effect all segments including the green one? e.g. spells with mystic damage?

[arma]

Well there's no real general rule that takes the area as the base to fiddle with (we didn't want to put you through some of the trouble, say, some versions of DnD put you through by drawing lines across the battlemap to see which side some line touches from what point of origin), but the main rule that takes care of this is really line of sight and targeting. Also, because these effects are not entirely physical, even though they behave that way because they mimic natural phenomena.

For example Blizzard Sphere mimics a natural blizzard, but it is still targeted, and still a magical thing and not a real blizzard. You choose who is affected, and you could well choose that your buddies remain unaffected. That means that while they are standing within a blizzard that freezes opponents, they don't suffer from it. The AoE component of spells like that is more like "you can pick a number of people who're standing close together" mechanics wise. Any obstacles usually affect who you can pick. And for areas you can't actually see, you can't usually make these a target.

You'll find spells where something that blocks an area doesn't really have an impact by looking at the ones that don't actually have targeting when casting, e.g. it is not applied to "people in an area" but to an actual area.

For example, Alarm. The casting is applied to an actual area, not someone who enters it. It is just the effect that causes someone entering the area for an alarm to sound. The area is the target, not the person.
Now, you may still say that this doesn't stretch through a solid wall, because you can't see the other side. If you imagine this spell to apply to the ground, you can't cast it on the ground you can't see. Now, if there isn't a wall when you cast it, and you then quickly build it, it will apply to the other side, because you saw it when you cast it. And if someone walks into the area on the other side of the wall, he will trigger the alarm.

[arma]

I've just discovered over in another thread where galafrone copy-pasted the whole spell (it is split to two pages in the book, so I simply skipped over some of it I guess, but I've stopped complaining to layout about those things ;D ) that you can also place this spell on objects, not just areas (you had the choice between object or area in ED1 explicitly, we just use "target" in ED3 which could be both).
The explanation above still fits if you choose area, in any case.
If you choose object, targeting isn't an issue any more for seeing the area, and this would then also be an example spell with a "mystic" effect that wouldn't be blocked by a non-magic wall.

[lortas]

So just for my understanding a fireball in this situation

line of sight & area of effect

LoS+AoE.png (13.45 KiB) Viewed 6037 times

would only effect the segment red and pink. Even yellow which in line of sight of the caster is "protected" by the stone wall from the centre of AoE.
Are only the spell defenses of characters which could be effected (red+pink) relevant that the fireball works (PG.170: ... spell casting test against the highest spell defense ...) or are all characters in all segments relevant.

If the spell in the figure was not a fireball but a Ethereal Darkness all segments (even the green segment) will be effected (while the walls are non magical)?

[arma]

Again: it's about targets, not who is in an area.
Go with what you target, not what is in the area.

In detail:

Casting fireball, you determine an area, and then you pick a number of targets within that area. At this point, you may well stop thinking about any area, because your targets have been determined. This is what the spell description tells you to do. Determine a point of impact, from there outwards determine an area, now pick targets from within that area. Now resolve the spell against these targets.
If you have a situation where there's obstacles, you may add cover or decide the spell is blocked, but the main thing is if targeting is resolved, the targets can be affected.

Casting Ethereal Darkness, this works the other way around, as the description tells you. You determine a target, cast the spell, and then the effect is in an area.