D&D 5E Knowing of a threat without noticing it

[Imaculata]

Which is great in theory, but in this case it's from a totally expected angle since the infiltrated PC is detected.

In that case, its pretty clear that no stealth checks are needed. They are not surprised.

 

[jaelis]

Okay, another tricky one:

The PCs know that enemies are coming and are ready to attack them the moment they appear. However, the enemies have the plan to ambush the PCs and they all succeed their stealth roll. Are the PCs surprised or does knowing that enemies are approaching already count as noticing a threat?

IMO, if the PCs know that enemies are present then they shouldn't be surprised, but it has to be a situation where they basically know who and where the enemies are, just not exactly where they are hiding. Simply being on guard isn't enough.

Alternatively, if there's an obvious place an enemy could be hiding, and the PC's specifically say they are watching it, then I wouldn't grant surprise either. Like if there's an arrow slit in the wall and the PCs say they will move past it carefully in case there is an archer.

In those kinds of cases, if the ambushers nonetheless hide successfully, I would instead grant them first place in the initiative order, since they control the start of combat.

 

[iserith]

Except, they can still hide in the darkness.

The question was whether or not they would be surprised knowing that their ally was leading the monsters to them, the uncertainty of which is resolved by Dexterity (Stealth) versus passive Perception. I would say there is no roll in this case given the context. If you want to rule that the monsters can try to hide to gain some advantage other than surprise and that the result is uncertain enough to call for an ability check, that's a separate issue.

 

[Hriston]

A PC (which the enemies consider a friend) lures them to the position agreed on. The PC actually failed his stealth role, so the PCs know of his position, but they don't know where any of the enemies are because they are all hiding successfully (though they could guess they are close to the PC).

The hidden PC counts as a threat to the other adventurers because he's trying to hide from them. There is no surprise after all.

 

[DEFCON 1]

For me, I'd look at the narrative story of the situation to figure out what the intent is, and then only apply any rules if there's a question.

So if the party of PCs have made the plan "So-and-so will go to the enemies and bring them back to us so we can ambush them..." the characters who stay back know that when So-and-So returns, he's going to have the enemies with him (unless of course he just walks back casually and calls out "It didn't work guys! They aren't here!" or whatever).

So no... when the remaining party sees So-and-So return, they have prepared their ambush for the enemies. They are not Surprised because the purposes of this encounter, So-and-So is a member of the other group. Now as was mentioned above... if the enemies were trying to sneak along as they traveled just in case, they would get to make DEX (Stealth) checks (either individually or as a group depending on how the DM chooses to rule it) and those are compared to the party's Passive Perceptions. By the same token... the party of PCs would probably also make DEX (Stealth) checks (again, either individually or as a group) and those would be compared to the enemies Passive Perceptions. Although in this case... if the enemies Passive Perception was less, then they WOULD be Surprised for the first round, because they weren't expecting So-and-So to be leading them into an ambush.

So in my ruling as the DM... once initiative is rolled, the PCs get to go in the 1st round regardless, because they are not surprised (having seen So-and-So and knowing he's brought the enemies with him.) Any enemies whose PP was higher than any party member's Stealth check are also not surprised, and would also get to go in the 1st round. And then finally... once each party member and enemy has chosen their target for the 1st round, I'd compare each Stealth check of the attack versus the PP of the target, and anyone whose Stealth was higher would get Advantage on their attack due to being Hidden.

(And as an addendum... when comparing Stealth checks to PP, because the PCs have more knowledge than the enemies do that ambushes are nearby-- because So-and-So is the red flag telling the PCs the enemies are here-- I probably would have the enemies receive Disadvantage on their Passive Perception to denote the difference. It's not necessarily necessary to do this, because the bonus the PC are already getting is that some enemies are going to lose their 1st round due to Surprise anyway... but if the ambush is really that good or So-and-So did a fantastic job in setting the enemies up (say perhaps a really good Deception check), then maybe I'd give that additional bonus to the PCs so that even more enemies will end up Surprised.)

 

[Caliban]

I know some DM's allow an unofficial "cheap shot" round - your opponent may not be surprised but you make an unexpected attack that takes them off guard. In this situation they'll allow a single action or bonus action, but nothing else. Then initiative is rolled.

Not in the actual rules, but it makes a certain degree of sense if you don't feel the situation warrants giving the PC a full round of actions.

 

[Blue]

Hmm interesting.

I read "Noticing a threat" as two requirements:
- You need to notice something
- That something is a threat

So noticing an ally or knowing of a threat both only meet one of the two requirments -> Surprise.

But of course you could see threat not just as a single person but actually an event. And the friend approaching plus knowing he is with enemies, could create a "area blob with some enemies in it" which itself could be consider a threat that is noticed.

Yes - the PC is a threat because they know he is accompanied by foes.

But either way, 5e isn't that mechanistic - rulings not rules.

Think of it like this - if one PC missed a perception check and another said "foes coming", you wouldn't discount it because the second PC wasn't a threat. Same here - a PC has done something to let them know the threat it here.

 

[clearstream]

Okay, another tricky one:

The PCs know that enemies are coming and are ready to attack them the moment they appear. However, the enemies have the plan to ambush the PCs and they all succeed their stealth roll. Are the PCs surprised or does knowing that enemies are approaching already count as noticing a threat?

I had the converse of this situation last night. The PCs wanted to ambush foes who knew they were there. I ruled that as the foes were alert, they couldn't be surprised by the PCs simply hiding in roughly the place that they spotted them. Perhaps if the PCs had been able to attack from a completely unexpected angle they might have achieved surprised.

Generally surprise for me isn't just making use of Stealth, it is making an attack when none is expected. There can always be exceptions of course.

 

[Rya.Reisender]

The question was whether or not they would be surprised knowing that their ally was leading the monsters to them, the uncertainty of which is resolved by Dexterity (Stealth) versus passive Perception. I would say there is no roll in this case given the context. If you want to rule that the monsters can try to hide to gain some advantage other than surprise and that the result is uncertain enough to call for an ability check, that's a separate issue.

Hmm, but I see being stealthy the requirement to even checking for surprise.
I mean if a group hides to surprise the enemies (under normal conditions), would you let them roll stealth twice? Once for hiding and once for checking if surprise is successful?

 

[iserith]

Hmm, but I see being stealthy the requirement to even checking for surprise.
I mean if a group hides to surprise the enemies (under normal conditions), would you let them roll stealth twice? Once for hiding and once for checking if surprise is successful?

No, that would be just the one Dexterity (Stealth) check. I don't see a reason to roll twice.

Your situation is different though because of the specific context. I would rule no surprise is possible (and there is no ability check), but gaining the benefits of hidden (to the extent the environment allows for it) might be an ability check. I would likely not separate it out this way though. I don't see any upside to the play experience for making things more complicated. Whether the PCs succeeded on the ambush they're trying to lay would, in my ruling, probably be tied to how the infiltrating PC did on his or her tasks with success meaning the PCs get the jump on the monsters later when said PC leads them into the ambush.