Need help with darkness/invis in combat

[Hawkshere]

My problem basically boils down to a simple question of targeting invisible opponents (although, technically a bit more complex than that). I could have sworn that, in addition to the miss-chance rules for 100% concealment, there are some kind of rules for determining what square an invisible enemy is in and/or a to-hit modifier other than the 50% miss-chance.

I couldn't find anything last weekend during the game, and didn't want to hold things up about it. As a result I'm left with the feeling I let my players off easy. Here's the situation in detail:

A villain NPC is ambushed by the PCs. The NPC has an item giving off darkness for the entire encounter, so when the PCs first initiate the encounter, they attempt to dispell the darkness, unsuccessfully. As soon as the NPC becomes aware of the PC's presence in the room, she attempts to escape outdoors by activating her cloak of the bat and making a 40 ft. move out the door.

The PCs can see the 20 ft. sphere of darkness moving through the room and out the door, and can hear the screeching of the bat (and thus have a pretty good idea what's going on). One of the PCs in the room gives chase by moving into the darkness and attempts to grapple the bat. The PC has enough movement to do this, no problem.

Both the PC (an elven ranger) and the retreating bat are now in the darkness effect. What do you think should be required of the PC to successfully grapple the bat under these conditions?

 

[AuraSeer]

There is no AC modifier or attack penalty for concealment. If you're targeting the correct square, and you pass the 50% miss chance, you make a normal attack on the invisible opponent.

You can pinpoint the square of an invisible opponent by making a DC 20 Listen check. The DC can be modified by distance, and by the amount of noise the opponent makes (DM call).

Your PCs should have had it easier, since they're outside the darkness effect. Since it's an obvious sphere, and they can see the outer edges, they can figure out where the center is. If the bad guy is standing in the center, they can pinpoint his square with no trouble.

AFAICT, the ranger should have had a perfectly normal grapple check on the bat, with the addition of a 50% miss chance. If you want it to be harder, you can always add circumstance penalties to the attack roll; it might be appropriate in this case, especially if the ranger didn't expect his target to be tiny or flying.

 

[Hawkshere]

Thanks for the quick reply!

Can I get a reference on the Listen check to locate the target square? I couldn't find that Saturday to even consider whether to use it or not, but I knew there was something like that. A page number or SRD reference would be great.

Actually, I ran it pretty much as you stated. Despite the fact that this took place at night, the elf PC's nightvision would clearly showed him the outline of the spell effect. I considered requiring a simple INT check for resolving the geometry, but ended up saying the hell with it, and just gave him his normal attack. So, 50% miss-chance aside, it was pretty much cake for a 7th level ranger to grab the bat.

Not an auspiscious beginning of the day for the bat, I can tell you.

 

[AuraSeer]

Check the description of Invisibility on this SRD page. It has the DCs for pinpointing unseen creatures.

FTR, I misremembered the rule. There's a given DC for hearing a creature "somewhere in that direction", and beating that DC by 20 allows pinpointing of the square. For a creature that's not actually in combat, the base DC depends on its Move Silently check, so pinpointing it could potentially require a very high number.

 

[Hawkshere]

Yeah, I see that - thanks!

Still, I feel better about how I ruled that encounter - it wasn't really invisibility, and I agree it should be relatively trivial to locate the target square in the center of a darkness spell.

 

[Legildur]

Don't forget that moving in complete darkness reduces you movement rate to half and...
From the SRD:

Blinded

The character cannot see at all, and thus everything has full concealment to him. He has a 50% chance to miss in combat, loses his positive Dexterity bonus to AC (if any), and grants a +2 bonus on attack rolls to enemies that attack him, just as if all his enemies were invisible. He moves at half speed and suffers a -4 penalty on most Strength and Dexterity-based skills. He cannot make Spot skill checks or perform any other activity (such as reading) that requires vision.

Pinpointing with Listen check at DC20 would be feasible (screaching bat noises), but as I noted above, movement rate is halved (unless Ranger has the Blindfight feat).

Does Cloak of the Bat grant Blindsight? If not, then the Ranger gets a +2 attack bonus for being 'invisible' - but still suffers the 50% miss chance.

[EDIT]added the Blinded quote[/EDIT]

 

[shilsen]

Can I get a reference on the Listen check to locate the target square? I couldn't find that Saturday to even consider whether to use it or not, but I knew there was something like that. A page number or SRD reference would be great.

DMG, pg.78. has all the information and the DCs you need.

 

[Spatzimaus]

See, situations like that are why I love Psionics: cast Vigilance at the start of the day, run into the sphere, and play whack-a-bat.

The rules have always seemed a bit iffy to me on this. If you're outside the sphere of darkness, you should be able to figure out more or less where the center is, but probably not well enough to aim an individual arrow or something. Why? Because from your point of view it's just a half-circle of darkness; the only way you'll know how far away it is is if you know its radius or can get parallax on it. Or, I suppose, if you managed to get some elevation, which'd make it more than a semicircle.

Either way, I'm somehow guessing that most Barbarians can't do the three-dimensional geometry needed to accurately aim. Ergo, the 50% miss chance for full concealment seems closer to me than saying "I can figure out where the middle is, I'll target that point." I don't know, maybe allow an INT check to drop the concealment to 30% or something?

 

[jlhorner1974]

I would say that observing the size of the circle and being able to locate the center point would help you determine which square to aim into, but it should not be allowed to reduce the miss chance due to concealment.

I know what you mean -- if the darkness is a 20' radius, you should be able to locate exactly where it's center point is, which is presumably inside of the creature it is affecting. However, is darkness is cast on an item, the item could be carried in either hand, fastened to your leg. This method of pinpointing the creature holding it is inaccurate and unreliable, at best.

Also, said creature could duck down or even get on hands and knees and crawl around so arrows aimed at his torso go over his head. You may see the darkness sphere sink into the ground a bit, but now you cannot even see half of the sphere so it is even harder to judge where to aim by visually estimating where the center of the sphere is.

After all, you don't have to tell your DM where you are aiming on the z-axis (up and down) within the 5' square, just which square you are aiming at. It is a pain to try to figure out exactly where within the 5' square the target is. The 50% miss chance reflects an average probability of hitting the target when they have total concealment.

Besides, it is assumed that all characters are constantly moving and making minor adjustments that do not change its position -- for example, dodging to the left 6 inches to avoid a spear thrust , ducking to avoid an arrow -- this does not count as movement in the D&D sense.

But even more than that, you are trying to implement something that basically pinpoints the location of a creature within a square, and I say that the whole ruleset was not designed for this. After all, in terms of targeting things, the smallest unit in the game is one 5' x 5' square.

With that in mind, I would say that the small movement of the sphere of darkness is noticable, but that it is not enough to improve your targeting to be able to aim more accurately without being able to see the target, due to the constant tiny movements made by the target. Due to the abstract nature of AC, even a movement of a half inch could make the difference between an arrow hitting a vital area, hitting a reinforced area of the armor, or missing completely..

Anyway, the rules are pretty clear. You pick a square and there's a 50% miss chance due to concealment. If you let characters reduce the miss chance just because of trying to pinpoint/triangulate the center of the area, darkness becomes weeaker and it makes feats, class abilities, and weapon enhamncements that reduce miss chance due to concealment much less powerful.

 

[Hawkshere]

Does Cloak of the Bat grant Blindsight?

The cloak allows you to transform into a bat, among other effects. Bats have blindsight. Thus, the attempt on the part of this NPC to combine the effects of darkness and the cloak.

He moves at half speed and...

Hmm. I did not consider the reduction in movement. However, we weren't using minis on a grid at this point, since it didn't seem that important. Under the circumstances, I remain willing to give the player the benefit of the doubt in terms of movement. In the future, though, I will definitely keep that reduction in movement in mind...