Does ranged magic that requires line-of-sight also require line-of-effect?

Question

This came up during a combat last week. The party had barricaded themselves behind double doors and the wizard was peering through the keyholes, dropping Scorching Bursts on anything foolish enough to enter his vision. While I readily admit that the "Sorcerer Tim" aspect of this scenario is entertaining and did make for a good encounter, I wonder what the rules are for ranged magic and its necessity for line-of-effect.

Is there a hard and fast rule on how to determine whether a spell requires line-of-effect or not? For instance, I wouldn't have allowed a Fireball or an Acid Arrow to have been cast that scenario simply because my understanding of how the spell manifests would not allow it to function in that fashion. Some of this is vaguely addressed in the PHB section on combat regarding cover and concealment, but none of it is explicitly laid out.

Answer 1

From the compendium entry on the area keyword (used in Scorching Burst)

You choose a square within an area attack’s range as the attack’s origin square, which is where you center or start the area of effect. You need line of effect from a square in your space to the origin square. For a target to be affected by an area attack, there needs to be line of effect from the origin square to the target. You don’t have to be able to see the origin square or the target, and concealment between the origin square and the target doesn’t apply.

So, Scorching Burst doesn't require line of sight, but it does require line of effect.

As ranged powers, the other spells require both.

Teleportation requires line of sight but not line of effect, so I think scrying should work.

Answer 2

I seem to recall them covering a lot of your questions in a podcast a couple years back. Ranged attacks require both line of sight and line of effect.

Try page 273 of the PHB and the portions on Line of Sight and Line of Effect.

I think its safe to say that a door blocks line of effect which is required for all attacks. I'd say scrying would fall into the same category. Although I suppose if you were scrying around a cloud of darkness, this wouldn't be the case.