Order of Operations

[Celanian]

For area effect attacks, does the damage happen exactly simultaneously or does the damage occur in order from nearest to furthest away from the attacker?

A BCD

Suppose A casts a line spell towards B-D. Would B get hit first or would all of them get hit at the same time?

Sometimes the order of who takes damage does matter. If B had a contingency that a globe of invulnerability would pop up if hit by an area effect spell, C and D would be protected if the attacks weren't simultaneous. Similarly if D had that contingency, B and C would've been hit by the area effect first if the attacks are sequential.

[Cuuniyevo]

It depends on the spell. A 'burst' attack (such as Fire Breath) comes from one source and extends outward, while a 'spread' attack (such as Fireball) does much the same, but can be cast from a distance. Meanwhile, there are some other spells that seem to come into existence across the entire area at once. Wall of Fire, for instance says: "An immobile, blazing curtain of shimmering violet fire springs into existence." So Wall of Fire would effect everyone along the path at the same time.

What spell are you thinking of using?

[Celanian]

It would be logical that B gets hit first and then C and then D, but is there any rules support for that?

[Abraham spalding]

If the contingency is set for when you are hit by a spell you first have to be hit by the spell.

So no one would be protected for the first such spell.

If the contingency was set for the AOE being about to hit you then it would go off instantaneously protecting everyone the instant before they would have all instantaneously taken damage from the AOE.

Of course if it was a delayed blast fireball or Cone of Cold they would take damage anyways since those are over 4th level...

Long story short:

If the protection spell is preemptive it would protect anyone under its purview equally (or not) since the damage is literally instantaneous from the spell (meaning at the exact same time).

There is no "delayed order" -- everyone gets it at the same time, unless the spell specifically states otherwise.

[Celanian]

Let's say A casts lightning bolt.

B is not too bright and his contingency is set for "immediately after I get hit by a lighting bolt" the globe is triggered. The lightning bolt hits B who takes the damage and the globe is triggered. Does this happen before C and D get hit or do all 3 targets get hit by the bolt?

[Abraham spalding]

All 3 targets get hit because the spell doesn't trigger until after you get hit by the lightning bolt (meaning you've already taken damage).

All damage from lightning bolt is instantaneous meaning it all happens at the same time.

So B took damage at the same time C did who also took damage at the same time D did.

This is why you cannot sneak attack more than one person with scorching ray for example -- they are all hit at the same time and you can only focus on one to make the necessary aim to sneak attack more than one at a time (so the theory from the FAQ goes).

So with the case you just gave everyone would take damage and then the globe would go up.

[Byakko]

I was going to say that it hits everything in the area simultaneously, but there's considerable verbiage to suggest otherwise in the magic section. Thus, I'm going to say it's actually kinda ambiguous whether the damage is perfectly simultaneous or not.

Normally, this won't matter and the damage is effectively simultaneous, but there are some corner cases where it might.

Note, these could all be interpreted to simply be descriptions of which areas are affected, but it's not far fetched at all to believe the spell's effects also flow and extend outwards as specified when cast.

Quote:

Spread: Some effects, notably clouds and fogs, spread out from a point of origin, which must be a grid intersection.

Quote:

Area: ...Regardless of the shape of the area, you select the point where the spell originates,...

Quote:

Burst, Emanation, or Spread: Most spells that affect an area function as a burst, an emanation, or a spread. In each case, you select the spell's point of origin and measure its effect from that point.

... A burst's area defines how far from the point of origin the spell's effect extends.

An emanation spell functions like a burst spell, except that the effect continues to radiate from the point of origin for the duration of the spell. Most emanations are cones or spheres.

Quote:

A line-shaped spell shoots away from you in a line in the direction you designate. It starts from any corner of your square and extends to the limit of its range or until it strikes a barrier that blocks line of effect. A line-shaped spell affects all creatures in squares through which the line passes.

[Abraham spalding]

Valid stuff but consider:

Quote:

Instantaneous

The spell energy comes and goes the instant the spell is cast, though the consequences might be long-lasting.

So I offer:

The damage happens instantaneous, but if there is something in the path then the things behind would not take damage.

So three people with a wall between number 2 and number 3
lightning bolt along the line they are on

Lightning bolt is intercepted by the wall doesn't break it and number 3 won't take damage.

However Number 1 and number 2 will take damage and do so at the same time, which is also the same time the wall does.

This exact situation is why point of origin and direction of effect matter but that doesn't mean people are hit at different instances.

[Byakko]

Yeah, "Instantaneous"... although how can a fireball that is truly instantaneous actually affect anything? There's gotta be some time involved, even if it's really small. Anyway, that's starting to get into metaphysics, so I'll get on-board and say, yeah, it happens too fast for anyone to react to.

Non-instantaneous spells, however, could be reacted to, perhaps... (for instance, a Stinking Cloud or a Black Tentacles)

[Abraham spalding]

It's Magic!

smoke bomb

[Byakko]

But wait, can magic defeat magic?

[Abraham spalding]

Byakko wrote:

But wait, can magic defeat magic?

It's like an unstoppable force meeting an immovable object, the problem is your problem is ill defined.

[Celanian]

It doesn't make intuitive sense that it's simultaneous. With a spell, you can kinda handwave it away by saying MAGIC. With something like a breath weapon, the effect clearly starts from a distinct origin point and travels outward. There are some non-magical equivalents of breath weapons such as flamethrowers so you can't even claim MAGIC in such a case.

[Cuuniyevo]

I believe Abraham spalding's point was that if the globe was cast after the caster was hit, then it's too late to stop the bolt from shooting past and hitting the others.

If you get the globe up before the bolt reaches you, then yes, the Lightning Bolt would not hurt you. It specifically says that it "begins at your fingertips" and can be stopped by sufficient barriers. It's a 3rd level spell, which Lesser Globe of Invulnerability can block. However, this is very important to note: The globe only suppresses the spell, and says any spell can pass through the globe and out the other side. The globe has a 10ft radius, so your allies would need to be within range to be protected. Otherwise, the Lightning Bolt would seemingly disappear as it went through the globe, ignoring you, and then seem to reappear behind and hit any target remaining in its path. This means that a different warding spell may be a better choice for your contingency, depending on the situation. Wall of Force, for instance, though it is a 5th level spell, not a 3rd.

[Komoda]

There is no such thing as instantaneous in the physical realm. All time measured can be halved. Therefore, nothing can actually happen instantaneously. Instantaneous is a theoretical device.

As a game rule, it is played as if instantaneous actually exists. As such, all people are damaged instantaneously and not one after another. Cover can help due to the direction of the source of some spells, as others have pointed out, but the time taken is still instant.

If your trigger goes off before it hits you, your effect affects everyone before the triggering event. If it doesn't go off until after you are affected, then everyone else is affected also.