Cover and shooting - through a wall?

[hyphz]

Here's the situation:

   A
   ###
   B

A and B are characters, #'s are a wall. North is towards A.

A is able to draw a line from the southwest corner of his space, to the northwest corner of B's space. (Per PHB, a line which passes along the edge of an obstacle isn't blocked.). He is also able to draw a line to the southwest corner of B's space. Either of these lines can also be taken as line of effect.

Thus, A can shoot B at just a -2 for normal cover? Is this really right?

 

[Benimoto]

No, if you want to get technical about it, a line that passes along the edge of an obstacle does block line of sight, but it does not provide cover. See the diagram on PHB page 274.

 

[Hypersmurf]

While lacking Line of Sight is inconvenient (total concealment, pick a square, -5 penalty to attack rolls), it's not as much of a problem as the lack of Line of Effect. Since no line from your square to their square does not at least touch an obstacle, you may not make an attack into the square.

-Hyp.

 

[SableWyvern]

Either of these lines can also be taken as line of effect.

As per my responses on RPG.net and hypersmurf's comment above, no, they cannot. (PHB p273)

 

[Hypersmurf]

Yeah, I missed that the OP had incorrectly used the phrase "line of effect" in his post.

A line that touches an obstacle or runs along a wall is considered unblocked for the purpose of determining how much cover someone has, but it's considered blocked for the purpose of determining whether any line of sight or line of effect exists.

So if there were line of effect, your scenario would consider there to be two unblocked lines when determining cover, and the penalty would be -2. But the penalty is immaterial, since no line of effect exists, and no attack can be made to which the penalty might be applied.

-Hyp.

 

[hyphz]

Ok, if that's agreed.

The unclear bit is that the rule about "a line that runs parallel to an obstacle isn't blocked" doesn't say anything about applying only to that section of the rules. It seemed to me that it defined the term "blocked" for the whole book.

 

[Hypersmurf]

Ok, if that's agreed.

The unclear bit is that the rule about "a line that runs parallel to an obstacle isn't blocked" doesn't say anything about applying only to that section of the rules. It seemed to me that it defined the term "blocked" for the whole book.

Well, read 273 again:

Line of Sight: You can see the target if at least one line doesn't pass through or touch an object or an effect - such as a wall, a thick curtain, or a cloud of fog - that blocks your vision.

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.

Benimoto ponits you to the diagram on p274, which illustrates a line that barely kisses a corner does not permit line of sight. However, that same line would be considered unblocked for purposes of determining how much cover someone had - if one line is clear, two lines are blocked, and one line barely touches a corner, they only have normal cover, not superior cover, because the "barely touch" line doesn't count as blocked for cover purposes.

-Hyp.