Opportunity attacks vs. invisible enemies?

[Tellerve]

This is where it is getting too nitpicky with the definitions I fear. See is what they wrote, but you can "see" where the invisible guy is in the square. Would you not allow an AO for a human at dusk when a goblin moves by him? Of course you would, at least I hope you would. The goblin has partial concealment. The invisible goblin has total concealment but since he hasn't passed his stealth check you know what square he is in and where he was moving, and instead of the partial concealment of dusk, you take the total concealment of invisibility (-5).

On your turn you don't need to make a minor action for the perception check. In fact, as long as the invisible enemy isn't trying to be stealthy then there is no need as you can clearly tell which square he is in by the rules in phb2. Using the minor perception would be if you loose him because he uses stealth on you and you loose which square he is in. Either way it is still -5 to hit him, so save your minor action.

 

[Oompa]

Phb 273 Seeing and Targeting:

To determine whether you can see a target, pick a corner of your space and
trace an imaginary line from that corner to any part of the target’s space. 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.

--

So if i know where a creature is, i can effectively check if i can 'see' it..

 

[Regicide]

Phb 273 Seeing and Targeting:
So if i know where a creature is, i can effectively check if i can 'see' it..

No, you can check if there is any terrain blocking you from seeing it. This has nothing to do with invisibility.

PHB 281
INVISIBLE
-You can’t be seen by normal forms of vision.
-You have combat advantage against any enemy that can’t see you.
-You don’t provoke opportunity attacks from enemies that can’t see you.

In two places in the PHB, both OA and Invisibility rules clearly state that you can't OA people that you can't see. What the heck?

 

[AngryPurpleCyclops]

No, you can check if there is any terrain blocking you from seeing it. This has nothing to do with invisibility.

PHB 281
INVISIBLE
-You can’t be seen by normal forms of vision.
-You have combat advantage against any enemy that can’t see you.
-You don’t provoke opportunity attacks from enemies that can’t see you.

In two places in the PHB, both OA and Invisibility rules clearly state that you can't OA people that you can't see. What the heck?

Seems pretty clear to me as well. It might have been played wrong in our game though because heavily obscured is only -2 if you're adjacent.

 

[AbdulAlhazred]

Yeah, it is absolutely clear, invisibility makes you IMMUNE to OAs. Being hidden has nothing to do with it.

To make the other situations more clear, if someone is invisible and not hidden you know what square(s) they are in. Thus you can attack the square (-5 to hit), you don't need to make a perception check to do that. In fact there is NO benefit to making a perception check against a non-hidden invisible enemy.

If an enemy IS hidden and invisible then you can make a perception check, minor action, to overcome their stealth and determine which square(s) they are in. Once you do that you can attack them (again with a -5 to-hit penalty). At that point they ARE no longer hidden from you, although the hidden creature could subsequently move and hide again.

You can also ALWAYS target a square instead of a specific creature with an attack. It will be a -5 to-hit penalty. This is useful for playing "sub-search" with hidden invisible opponents, or opponents behind total cover. The DM should roll the to-hit in these cases and just tell the player if it was a hit or a miss so that the roll can't reveal whether or not there is even a target in the square (if not then the attack is an automatic miss, you don't want the player to know that).

Pretty much all the same considerations apply to being hidden WITHOUT invisibility. Enemies can always target your square, though in general they will be simply guessing if you are there or not. OA is also not possible against a hidden target since being hidden means you are "invisible to the enemy".

There is a slight ambiguity however. Suppose you are hidden next to an enemy and you move away. Moving more than 2 squares forces a new stealth check, but at the instant you start moving, you haven't yet moved (and might not even move 2 squares), so does the enemy get an OA? It isn't really clear. There are a few ways a DM could rule. 1) There is no possibility of an OA if you are moving less than 3 squares. 2) There is no possibility of an OA at all because you have not YET moved more than 2 squares. Furthermore does it depend on whether or not you are breaking cover? The gist of it is, at what point in your action do you become not hidden, and at what point in a move action where you move more than 2 squares do you become not hidden?

 

[AngryPurpleCyclops]

I think the context of this post has to do with an encounter with many city guards who surrounded both our rogue and our fighter during different points during the encounter. My wizard was behind a wall in a park and rather than let the guards just pummel our guys to death I moved stinking cloud on top of them thinking that taking damage from the cloud was way better than taking 4 OA. This allowed the rogue to get up from prone and move away(without the subsequent OA's) from the 4 guards and it allowed our fighter to stay on his feet in the middle of 6 attackers.

Upon reading the rules a couple times it looks to me like the rogue should have had to make a stealth roll in order to sneak out of the cloud without the OA's but the OA's should have been at -2 if they went off. part of me thinks how we played it makes more sense than having OA's because being partly blinded and inhaling poison would probably prevent you from being very effective at OA's.

 

[Zerakon]

I think the context of this post has to do with an encounter with many city guards

Haha, uh, no.

I posted the original question about 9 hours before that encounter.

I was simply prepping myself for your eventual doom when you face invisible enemies. Muhahaha.

 

[Regicide]

I was simply prepping myself for your eventual doom when you face invisible enemies. Muhahaha.

LOL! In your FACE Melee Training feat!

 

[GorTeX]

This is where it is getting too nitpicky with the definitions I fear. See is what they wrote, but you can "see" where the invisible guy is in the square..

No, you know where the invisible guy is, but you still do not see him, as he is invisible.

 

[AbdulAlhazred]

No, you know where the invisible guy is, but you still do not see him, as he is invisible.

Yup, exactly. And this is the main point of why invisibility is such a nice ability to have (well, besides making it a LOT easier to hide). Take away that advantage and really what all does invisibility do for you? It becomes just a debuff. Not BAD, but it was intended to prevent OA and balanced for that. Look at the difficulty in actually acquiring invisibility, especially invisibility that lasts anything past 1 round. This is also why monsters with special senses, like tremorsense, can be quite challenging, they aren't as restricted by visibility issues. If you nerf invisibility it would kind of reduce the value of those senses.