Question about burst

[scottchiefbaker]

His topic says burst, though his OP says blast. His example seems consistent with burst, too, so let's assume that.

Oh good point tale... I meant blast not burst. The topic is incorrect.

 

[Samir]

Oh good point tale... I meant blast not burst. The topic is incorrect.

There's no such thing as a "close blast 1." Are you sure you don't mean burst? If you did in fact mean burst, kerbarian's response is correct.

Depends where your origin for the blast is. It could hit the yellow guy if you set its origin one square down and to the left.

The origin square for a blast is your square. There's no way a close blast 3 from green, for example, could hit the yellow guy, because a blast affects a target only if there is line of effect from the blast's origin square to the target, which there isn't.

 

[Tale]

You did mean blast? Bugger, now I'm confused on blast/burst rules.

 

[Infiniti2000]

1) For the sake of bursts and blasts, cover is determined by the origin square. For a close burst (as you describe in this scenario) that is centered on the green dot, the red dot does not have any cover, while the yellow dot does have cover. The north-east corner of the wizard's square has direct line of effect to all four corners of the red dot's square. The south-west corner of the wizard's square has line of effect to two of the four corners of the yellow dot's square, giving it cover.*
<snip>
* This is how I rule cover. Other DMs might say that you cannot trace lines of effect along the edges of walls, but it's how I've interpreted the rules and its not caused any problems.

Is the wall two-dimensional? If you can place the origin on the north-east corner for one opponent, and the south-west corner for another...if I trace from the south-west corner, what obstruction does it hit? Doesn't it simply go down the (infinitesimally thin) wall? In other words if you move the green spot one square to the south west and yet pick the same corner, is it still cover?

 

[eamon]

To be clear; a close blast 1 affects precisely 1 square adjacent to the caster. It's a perfectly valid range for a power, but usually they call such powers "melee", since that's almost the same and everyone instinctively understands what that means.

 

[Samir]

Is the wall two-dimensional? If you can place the origin on the north-east corner for one opponent, and the south-west corner for another...if I trace from the south-west corner, what obstruction does it hit? Doesn't it simply go down the (infinitesimally thin) wall? In other words if you move the green spot one square to the south west and yet pick the same corner, is it still cover?

PHB 273 says

If every imaginary line you trace to a target passes through or touches a solid obstacle, you don’t have line of effect to the target.

Thus since every line you can draw from the SW corner of green touches a solid object (the corner of the wall), green doesn't have line of effect to yellow.

 

[Infiniti2000]

PHB 273 says ...

Thus since every line you can draw from the SW corner of green touches a solid object (the corner of the wall), green doesn't have line of effect to yellow.

Those lines are along the edge. Those don't necessarily go through the wall.

Move the green guy one square south and use the same corner for your adjudication. What's different in the rules text? Nothing I can see.

 

[Samir]

Those lines are along the edge. Those don't necessarily go through the wall.

Correct, but the text for line of effect says "touch or pass through," and every line you can draw from that corner will touch a piece of the wall. The rules for LoE are different that those for cover, which is determined by counting how many corner-to-corner lines are blocked.

Move the green guy one square south and use the same corner for your adjudication. What's different in the rules text? Nothing I can see.

If you move green one square south, you can draw some lines from green's SW corner that do not touch the wall at all. Thus, you have line of effect.

 

[kerbarian]

Those lines are along the edge. Those don't necessarily go through the wall.

Move the green guy one square south and use the same corner for your adjudication. What's different in the rules text? Nothing I can see.

Line of Effect: You can target a creature or a square if there’s an unblocked path between it and you—that is, if you have line of effect to it. If every imaginary line you trace to a target passes through or touches a solid obstacle, you don’t have line of effect to the target.

When you make an area attack, you need line of effect to the attack’s origin square. To hit a target with the attack, there must be line of effect from the origin square to the target.​

For line of effect, you don't choose a corner of the origin square -- that's only for cover. For line of effect, you trace every possible line from one square to the other, and you only have line of effect if you can find one that doesn't "[pass] through or [touch] a solid obstacle". From green to yellow, every possible line either touches or passes through the intervening wall. From green to red, there are plenty of lines connecting the two squares that don't touch any walls.

 

[Infiniti2000]

Ah, thanks for the explanation! I get it now and concur.