Fireball targeting

[StreamOfTheSky]

I think touch AC 18 sounds fair for the level of difficulty involved. 4-5 is just crazy, anyone could make that on "not a 1."

If it were an arrow or weapon-like spell, instead of making the attacker roll twice, you could be "nice" and make him roll only once -- the attack would have to hit (or touch, if a ray spell) the enemy archer and beat the slit's touch AC 18. The enemy would still get cover bonus to AC, of course.

 

[irdeggman]

If an arrow slit is only ac 4,5 or 14 to shoot through, how does it give someone behind it +8 to ac?

That has nothing to do with a spell and spread effect.

Spread effects do not go through walls, they do go around them (if possible) though.

 

[irdeggman]

The target can duck behind the wall part, so you have to aim cleverly through the slot, not just hit the slot.

Yeah - what he said. That is why you need to be able to shoot through the slot to get the fireball to get to the other side and not hit the wall.

 

[Legildur]

Yeah - what he said. That is why you need to be able to shoot through the slot to get the fireball to get to the other side and not hit the wall.

Except an archer behind the slit would not occupy that position for the entire round. They would be ducking back and forth, optimising the cover available.

 

[irdeggman]

Except an archer behind the slit would not occupy that position for the entire round. They would be ducking back and forth, optimising the cover available.

Maybe I misunderstood.

I see shooting through the murder slot as a one way shot for the archer which is difficult and provides the target with at least partial cover since the angle of the shot is impaired.

Anyone trying to hit the archer must get past pretty much total cover, at the very least cover that blocks line of effect. Spread effects (like a fireball) can negate this cover but must make it through the slit (hence the ranged touch attack).

 

[Vegepygmy]

A 2 inch wide, foot long slot seems diminutive to me, so that would be 10+4 size = 14 AC touch attack.

I'm no expert, but most pictures of arrow slits I've seen look something like this:

That's a little more than 2 inches wide, and a lot taller than 1 foot. But if you decide arrow slits in your world are Diminutive, that's fine: it'd be +4 AC for size, making the touch AC 7.

I think touch AC 18 sounds fair for the level of difficulty involved. 4-5 is just crazy, anyone could make that on "not a 1."

Maybe it's not supposed to be very hard. I mean, how do we know what "level of difficulty" is involved in firing magical beads of exploding fire through arrow slits? The rules to figure it out are all right there in the books; why some people don't want to accept them is beyond me.

And by the way, a touch AC 18 is equivalent to a housecat using Total Defense to avoid you. I think you may be setting the bar a little high.

 

[Elder-Basilisk]

Thats true, but considering the modest penalties for failure (ie. the spell still, goes off, just at the new location and the enemies receive a bonus to their save) I'm just not willing to let it be so easy its just a 2+ on the attack roll.

Thanks for the rules help though folks, guess i'm just gonna divert off them a bit on this one

Fireball and arrow slits is an interesting question--mostly because, if you follow the rules as written, it may enable fireball to bypass the normal line of effect rules.

The line of effect rules require a one square foot opening in the five foot square--a total of 144 square inches.

On the other hand, historical arrow slits ranged from the type that Vegipygmy posted (I suspect that is probably an english arrow-slit designed for use with a longbow) at about six feet tall by three inches or so (216 square inches, only 180 of which are in a single five foot square) to ones that are much smaller--perhaps two to four feet by three to four inches (4 feet by 4 inches is 192 square inches, but anything smaller than 3"x4' will be less than 144 square inches), or crossbow slits that were often the same 2-4 inches by 2 feet in a cross shape (176 square inches if four feet wide, but only 135 square inches if 3 inches wide). So, in short, historical arrow slits varied between just larger than necessary to provide line of effect to just smaller than is necessary to provide line of effect.

In a fantasy game, line of effect is a big deal, so it would make sense that arrow slits not specifically designed to allow spellcasting from inside would be designed to hit that "just too small to provide line of effect" mark.

Consequently, if you read the fireball text as allowing the fireball to bypass the ordinary line of effect requirements with a successful ranged touch attack, the consequences of failure would be that it has no effect at all on the targets behind the arrow slit. A successful touch attack, on the other, would give it full effect (and no effect on the outside of the arrow slit).

And for the record, I think that an AC in the neighborhood of 15-18 is probably more in line with the rest of the system than 5-7. You can extrapolate the lower AC from portions of the rules, but whatever we use, it should be harder to fire through an arrow slit than it is to hit an ordinary flatfooted human at the same distance and the human is much bigger. (As for the housecat, we all know the rules haven't ever modeled house cats well--in second edition, they regularly killed commoners )

 

[Runestar]

I can't imagine arrow silts being diminutive. Seems like they would screw over the archers trying to fire out of them as much as it would offer protection (it would probably be as difficult trying to fire an arrow out of such a small opening and hope to hit anything as much as trying to shoot inside the hole), unless they are using crossbows or the medieval equivalent of sniper rifles (wands maybe).

AC14 seems fair. IMO, it shouldn't be too hard to shoot something through the arrow slit (especially if it is as big as suggested by Vegepygmy), just difficult to both shoot into it and hit someone at the same time.

 

[Jeff Wilder]

I can't imagine arrow silts being diminutive. Seems like they would screw over the archers trying to fire out of them as much as it would offer protection (it would probably be as difficult trying to fire an arrow out of such a small opening and hope to hit anything as much as trying to shoot inside the hole)

No. It's the keyhole effect: press your eye against a keyhole, see most of the room. Kneel and try to look through a keyhole from 10 feet away, you see a keyhole.

 

[billd91]

Here's a how I handle it:

Normally, hitting a grid intersection with a grenade weapon is like hitting AC 5 (AC 10 - 5 for Dex 0, I presume). That's the base I would use. Add +8 for the AC bonus of the cover and that would give us an AC 13 to hit. Make that ranged touch attack and the fireball erupts at the intersection as planned.

I would not apply the inanimate object penalty to AC since you are not hitting an object. You are hitting a point in space.
Personally, I'm not at all sure I see a point to the -2 AC for inanimate objects. They already have a -5 due to being unable to move, so the additional -2 seems odd.