Attacks of Opportunity and Cover

[Herremann the Wise]

Hi Everyone,

I think the rules as written indicate that no attack of opportunity would be allowed. However, it does not seem to make much sense and so our group had a "discussion" on it last night.

Cover and Attacks of Opportunity: You can’t execute an attack of opportunity against an opponent with cover relative to you.

So far so good.

When making a melee attack against a target that isn’t adjacent to you (such as with a reach weapon), use the rules for determining cover from ranged attacks.

OK. We're dealing with a Huge Fire Elemental 15 foot-square with 15 foot reach. Let's have a look at the ranged attack information:

To determine whether your target has cover from your ranged attack, choose a corner of your square. If any line from this corner to any corner of the target’s square passes through a square or border that blocks line of effect or provides cover, or through a square occupied by a creature, the target has cover (+4 to AC).

Oh. Well that makes things a little more difficult.

In our case, there was a three foot halfling directly in front of the 32 foot tall fire elemental. One of our mounted characters moves up behind the halfling to give the elemental a prod with the lance (reach weapon) - moving through a square within the elemental's reach. Technically speaking from the above quotes, it appears that the halfling is providing cover for the mounted character and thus no attack of opportunity results for either the horse or the character.

To me, this does not make sense. Am I missing something here? The mounted character and his horse to my thinking should have been swiped - it is my character by the way.
What is going on?

Best Regards
Herremann the Wise

 

[Hypersmurf]

"Low Obstacles and Cover: A low obstacle (such as a wall no higher than half your height) provides cover, but only to creatures within 30 feet (6 squares) of it. The attacker can ignore the cover if he’s closer to the obstacle than his target."

When the mounted attacker is 15 feet from the elemental, he's 10 feet from the halfling, and the elemental's 5 feet from the halfling. The halfling is less than 16 feet tall. Thus, the elemental can ignore the cover.

-Hyp.

 

[Liquidsabre]

If the character was mounted then they should be taking up a 10-foot square (large-size mount). I don't think the halfling would provide cover for either the mounted character *or* the fire elemental using the ranged attack cover rules now woudl it? *checks battle mat*

 

[Herremann the Wise]

"Low Obstacles and Cover: A low obstacle (such as a wall no higher than half your height) provides cover, but only to creatures within 30 feet (6 squares) of it. The attacker can ignore the cover if he’s closer to the obstacle than his target."

When the mounted attacker is 15 feet from the elemental, he's 10 feet from the halfling, and the elemental's 5 feet from the halfling. The halfling is less than 16 feet tall. Thus, the elemental can ignore the cover.

-Hyp.

So to further complicate things, what if the halfling was flying at an altitude of 20 feet? Cover would then be provided?

If the character was mounted then they should be taking up a 10-foot square (large-size mount). I don't think the halfling would provide cover for either the mounted character *or* the fire elemental using the ranged attack cover rules now woudl it? *checks battle mat*

The size funnily enough makes it easier for the mounted character to have cover - with the line having a greater chance to pass through the "obstacle".

And so, to take this to the extreme, could we have a summoned celestial owl flying at 20' providing cover because it is the creature in the "square" providing cover - even though as a tiny creature it only takes up a 2 1/2 foot space?

I'm still a little confused on the possibly boundaries of interpreting this rule.

Best Regards
Herremann the Wise

 

[Hypersmurf]

If the character was mounted then they should be taking up a 10-foot square (large-size mount). I don't think the halfling would provide cover for either the mounted character *or* the fire elemental using the ranged attack cover rules now woudl it? *checks battle mat*

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Yeah, good point - the elemental can choose which corner of which of his squares he draws his lines from, and he can choose which of the horse's squares he draws the lines to all corners of.

If he draws lines from his bottom right corner to all four corners of the horse's bottom left square, none of them pass through the halfling's square, so the horse has no cover.

-Hyp.

 

[Hypersmurf]

The size funnily enough makes it easier for the mounted character to have cover - with the line having a greater chance to pass through the "obstacle".

No.

Big Creatures and Cover: Any creature with a space larger than 5 feet (1 square) determines cover against melee attacks slightly differently than smaller creatures do. Such a creature can choose any square that it occupies to determine if an opponent has cover against its melee attacks. Similarly, when making a melee attack against such a creature, you can pick any of the squares it occupies to determine if it has cover against you.

... oh, wait. That's melee.

Hang on.

... looks like with ranged attacks (or non-adjacent melee attacks, which use the rules for determining cover from ranged attacks), you draw your lines to the corners of the horse's space, not just one square of his space. So yeah, the horse would be able to hide behind the halfling, were it not for the fact that the halfling isn't 16 feet tall.

-Hyp.

 

[ThirdWizard]

Is there any rules precedence for 3-dimensional facing? In other words, if the elemental is indeed 32 feet tall, and the horse/rider is more than 5 feet tall, could you draw a line from a square 5 feet above the halfling?

 

[Hypersmurf]

Is there any rules precedence for 3-dimensional facing? In other words, if the elemental is indeed 32 feet tall, and the horse/rider is more than 5 feet tall, could you draw a line from a square 5 feet above the halfling?

It's not really gone into anywhere, I think.

If you give someone a 3D face, does a ranged attacker need to be able to draw a line to all 8 vertices to avoid cover?

-Hyp.

 

[Liquidsabre]

The size funnily enough makes it easier for the mounted character to have cover - with the line having a greater chance to pass through the "obstacle".

No Hyper got it I think.

If he draws lines from his bottom right corner to all four corners of the horse's bottom left square, none of them pass through the halfling's square, so the horse has no cover.

I had to look at my battlemat to make sure the sizes worked out right. The Large-mount and character do not receive cover from the halfling against the Huge Fire Elemental using the ranged attack rules for cover. So your character should have gotten a smack from the FE when you moved through it's 15-foot threatened area afterall.

I'm guessing no one picked the right corner to determine cover for the FE? Though it's interesting to see that the fire elemental would have had cover from the halfling against the mounted character.

Edit - Wait a tic. The fire elemental is not using a reach weapon (though it has natural reach) so shouldn't the FE be using the rules for melee cover anyhow?

 

[ThirdWizard]

If you give someone a 3D face, does a ranged attacker need to be able to draw a line to all 8 vertices to avoid cover?

It does look that way...

We've always played it that "Big Creatures and Cover" apllied to the target of ranged attacks. It looks like we were wrong, and as long as a 20' creature has 5' hidden from you, he has cover?