Do characters always know when they are threatened for an AoO?

[gadren]

I'm sorry if this has been asked before - it seems like something someone would have asked, but I couldn't find it.

Does a PC or NPC always know if they are threatened for an opportunity attack? For example, say an enemy is invisible, or has some sort of non-obvious ability that increases their reach, should I let a player know every time they are in a threatened square (and should NPCs always act as if they know)?

[Seward]

They know if they are in reach of an enemy if they have a way to detect that enemy.

I don't think they can know if they are threatened.

Certainly I've never seen anybody do that in play. What we do is make assumptions. We assume a dire wolf only threatens 5', where a hill giant threatens 10' etc, and act accordingly. It is common knowledge what reach a given body type and armament provides.

These assumptions sometimes bites you in the ass.

example1

Enemy is standing with a longspear. I have surprise, so I don't respect the threat and move through its threatened zone. That will usually work, but if longspear-guy has combat reflexes or uncanny dodge, he gets an attack, if he can perceive me.

Example 2

Enemy is standing with a longspear and has braced for a charge (so is not surprised). Not being an idiot, a high AC guy double-moves past him instead of charging and draws an AOO. His less armored but faster buddy now double-moves to flank the spearman, both inside his reach. Unfortunately for Mr Light Infantry, the Longspear guy has combat reflexes and takes a 2nd AOO

Example 3. I'm invisible and I move past the dire bear figuring my invisibility will keep me safe. Unfortunately the dire bear is actually a druid with listening lorecall and 5+ ranks of listen. The druid swats me with a paw and after the improved grab has an invisible cuddle-buddy.

Example 4. Rogue tumbles past the longspear at half speed, but to get to the flank needs to continue at full speed. Lucky that a longspear doesn't threaten 5' from enemy. Except said enemy has improved unarmed strike and kicks him in the face. (note that something like armor spikes are visible and would prevent this particular mistake)

Example 5. Mage steps back from the dire wolf and doesn't bother to cast defensively as he's out of reach. Unfortunately the dire wolf is actually a warshaper with extraordinary reach (reach that is explicitly not visible until it is used). Mage gets bitten, tripped and spell disrupted. Sucks to be him.

Example 6. Longspear dude is wearing a monk outfit instead of armor, has a shaved head, a holy symbol of a deity with improved unarmed strike as the deity's favored weapon. Rogue decides he probably has unarmed strike and tumbles both through the 10' reach and 5' reach and doesn't get a flank this round. Actually longspear dude is a sorcerer who dresses up like a monk to fool people - his AOO is pathetic but they guessed wrong. As the rogue readies till a teammate gets into a flank, he eats a color spray and is stunned.....

You get the idea.

[Rynjin]

Pretty much what Seward said.

Every character (and players) should be expected to know the default assumption. Creatures threaten adjacent to them, Large creatures have 10 ft. Reach, Reach weapons have increased Reach, etc.

But (without a relevant Knowledge check anyway) a character isn't going to know if it's a nonstandard monster who is Large with 15 ft. Reach for instance. Or if a creature has another ability that lets them threaten when they normally wouldn't.

[gadren]

They know if they are in reach of an enemy if they have a way to detect that enemy.

I don't think they can know if they are threatened.

Certainly I've never seen anybody do that in play. What we do is make assumptions. We assume a dire wolf only threatens 5', where a hill giant threatens 10' etc, and act accordingly. It is common knowledge what reach a given body type and armament provides.

These assumptions sometimes bites you in the ass.

example1

Enemy is standing with a longspear. I have surprise, so I don't respect the threat and move through its threatened zone. That will usually work, but if longspear-guy has combat reflexes or uncanny dodge, he gets an attack, if he can perceive me.

Example 2

Enemy is standing with a longspear and has braced for a charge (so is not surprised). Not being an idiot, a high AC guy double-moves past him instead of charging and draws an AOO. His less armored but faster buddy now double-moves to flank the spearman, both inside his reach. Unfortunately for Mr Light Infantry, the Longspear guy has combat reflexes and takes a 2nd AOO

Example 3. I'm invisible and I move past the dire bear figuring my invisibility will keep me safe. Unfortunately the dire bear is actually a druid with listening lorecall and 5+ ranks of listen. The druid swats me with a paw and after the improved grab has an invisible cuddle-buddy.

Example 4. Rogue tumbles past the longspear at half speed, but to get to the flank needs to continue at full speed. Lucky that a longspear doesn't threaten 5' from enemy. Except said enemy has improved unarmed strike and kicks him in the face. (note that something like armor spikes are visible and would prevent this particular mistake)

Example 5. Mage steps back from the dire wolf and doesn't bother to cast defensively as he's out of reach. Unfortunately the dire wolf is actually a warshaper with extraordinary reach (reach that is explicitly not visible until it is used). Mage gets bitten, tripped and spell disrupted. Sucks to be him.

Example 6. Longspear dude is wearing a monk outfit instead of armor, has a shaved head, a holy symbol of a deity with improved unarmed strike as the deity's favored weapon. Rogue decides he probably has unarmed strike and tumbles both through the 10' reach and 5' reach and doesn't get a flank this round. Actually longspear dude is a sorcerer who dresses up like a monk to fool people - his AOO is pathetic but they guessed wrong. As the rogue readies till a teammate gets into a flank, he eats a color spray and is stunned.....

You get the idea.

"They know if they are in reach of an enemy if they have a way to detect that enemy."

Is that an actual rule, though? I couldn't find anything about that, and that idea doesn't always make sense.

For example, while it makes sense to me to know that I am threatened by a reach weapon, I imagine I wouldn't know automatically that an unarmed enemy has improved unarmed strike or that an enemy with only a bow has the Arrow Mind spell or the Ranged Threat feat (from Dragon #350 that lets them threaten with a bow out to 15').

Like I'm prepared to just rule what makes sense to me as DM, but I wanted to know if there was an actual rule about this first, as I know the rules don't always make sense.

[Seward]

But (without a relevant Knowledge check anyway) a character isn't going to know if it's a nonstandard monster who is Large with 15 ft. Reach for instance. Or if a creature has another ability that lets them threaten when they normally wouldn't.

Depends how obvious it is. A clockwork creature with arms that varied in size (some going to normal reach, some approximating a reach weapon) would be pretty obviously dangerous at both reach weapon and normal weapon ranges. So would a giant squid, it is basically all tentacles, but you'd assume its beak has normal reach. You might not know how far a giant squid's tentacles reach without a kn check but you'd probably guess more than 5'.

An Otyugh? Less clear, and more up to the GM. Their tentacles have an extra 5' reach but if they're not extending them it might not be obvious and I'd have no issues with a GM requiring a Kn Dungeoneering check (or maybe scouting them without being seen and watching them for long enough to see them use their tentacles at full extension).



"They know if they are in reach of an enemy if they have a way to detect that enemy."

Is that an actual rule, though? I couldn't find anything about that, and that idea doesn't always make sense.

I worded that very carefully. You know you are in reach if you can detect an enemy. That says nothing about whether or not you know if they can take an aoo (ie threaten you).

I was describing what you can see, and this comment and a prior one (and my examples) can show how you might or might not be threatened even though you can see the reach of the enemy just fine. And sometimes the reach might be ambiguous if the enemy has unusual anatomy or concealed abilities that extend its reach.

And yes, to take your example of an archer or an unarmed person, you'd know that if they CAN take an AOO, their reach is probably 5' for a medium creature, 10' for a large humanoid creature etc. You would probably ASSUME they can't take an AOO unless they have some kind of marker that makes them different (visible natural weapon or spiked gauntlet or armor spikes for the archer, or all those monk "markers" my sorcerer example gave, or spellcrafting you casting arrow mind etc). But any assumption you make about that archer might be wrong (a hat of disguise could give fake natural weapon etc)

-----
To get back to your first question. No, there is no rule that says you know for sure if you are threatened. All you know is what you can perceive, but it is common knowledge what will NORMALLY threaten. After that what you know is based on what else you have learned (an Orc attack wave will learn who has combat reflexes the hard way. A wizard might know about arrow mind if she sees/hears you cast it and makes spellcraft roll. A ranger with favored enemy Aberration and some Kn Dungeoneering might know about Otyugh Tentacles etc etc)

[Khedrac]

I'm sorry if this has been asked before - it seems like something someone would have asked, but I couldn't find it.

Does a PC or NPC always know if they are threatened for an opportunity attack? For example, say an enemy is invisible, or has some sort of non-obvious ability that increases their reach, should I let a player know every time they are in a threatened square (and should NPCs always act as if they know)?

The way the Living Greyhawk campaign played it (which was supposed to be RAW with a few modifications) was that you only know obvious reach.

Something like a squid's tentacles or a dragon's neck I would say are usually fairly obvious, but something like a Boneclaw's reach is not going to be known without a successful knowledge check (or experience).

[loky1109]

One AoO feat, I don't remember what one, has specific clarification that enemy know that he is in danger of AoO. This specific clarification means in all other situations he doesn't.

[sleepyphoenixx]

One AoO feat, I don't remember what one, has specific clarification that enemy know that he is in danger of AoO. This specific clarification means in all other situations he doesn't.

Mage Slayer?

[loky1109]

Mage Slayer?

I think no, but can't find. Sorry.

[KillianHawkeye]

There's nothing saying that a character automatically knows they're being threatened, although it's usually pretty clear. It mostly comes down to what a character can perceive and a degree of common sense; beyond which requires special knowledge.

The most obvious, is you can't know what you can't see or perceive somehow. You can't know you're threatened by an invisible foe unless you can detect them somehow. Likewise, while many creature's reach can be determined by their size and their weapon choice, any non-obvious effect (such as a feat or a natural ability which allows one to extend their reach, or a weapon that can suddenly grow longer, or a spell that allows opportunity attacks with a ranged weapon) will probably not be known without special knowledge or experience with that particular foe.

It's totally okay for some situations like these to catch players by surprise. There's no rule saying you always have to do what the players expect. Some enemies have unusual abilities, while others make use of deceptive tactics. It's no different from using an illusion or disguise to hide a monster's true nature from the players.

[gadren]

Ok thanks all. It sounds like my initial “common sense” approach was the correct one, and that there are no specific rules on this otherwise.

[loky1109]

Found. It isn't feat, it's maneuver - Defensive Rebuke.

[gadren]

Found. It isn't feat, it's maneuver - Defensive Rebuke.

Ah yes, I remember that one.