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

[jaelis]

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.

Indeed, my interpretation is that you're surprised when you are attacked by an enemy you weren't aware of, not just by an enemy you didn't see.

 

[DEFCON 1]

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?

Of course not, because you aren't rolling to "surprise" an enemy. "Surprising an enemy" isn't an action you can take. The action you take is a DEX (Stealth) check to Hide, and if the opponent's Passive Perception is lower than that, you gain Advantage on your attack against them because you are Hidden from them.

Surprise only results from the other person's POV. If you aren't expecting a threat or an attack AT ALL at that moment... and your Passive Perception does not allow you to notice the creature who is Hidden, then you are Surprised. You do not get to act in the first round of combat.

The only reason why in your example that the party of PCs are not Surprised is because they knew that the other PC was leading the enemies to them as part of their group. So for that encounter the PC was considered a member of the enemy group and was noticed by the party because his DEX (Stealth) check (if he rolled one) was lower than the party's Passive Perception. Thus the party noticed the threat of the opposing party (the PC) and was not Surprised for that first round.

 

[iserith]

The only reason why in your example that the party of PCs are not Surprised is because they knew that the other PC was leading the enemies to them as part of their group. So for that encounter the PC was considered a member of the enemy group and was noticed by the party because his DEX (Stealth) check (if he rolled one) was lower than the party's Passive Perception. Thus the party noticed the threat of the opposing party (the PC) and was not Surprised for that first round.

And if you're that PC, I don't even know why you're trying to be stealthy if the whole purpose is to lead the monsters into an ambush. If I were that player, I most certainly would hope the DM didn't ask me to roll... because what if I succeed?

 

[Rya.Reisender]

I told the player that it's up to him if he wants to be stealthy or not, but if he doesn't roll then the others might get suspicious of him. So he decided to roll (and rolled a 1, lucky).

My point with the rolls was that for me, the moment someone wants to be stealthy, he rolls stealth (unless I determine it's impossible or trivial to be stealthy, which is definitely not the case here). For me the result of this roll is also used to determine if surprise is successful, but a successful stealth roll in the context still does not lead to surprise being successful, which I think is reasonable. What I found weird is that iserith said he would not even roll for stealth, but I think hiding should be possible, even if surprise is impossible.

 

[iserith]

My point with the rolls was that for me, the moment someone wants to be stealthy, he rolls stealth (unless I determine it's impossible or trivial to be stealthy, which is definitely not the case here). For me the result of this roll is also used to determine if surprise is successful, but a successful stealth roll in the context still does not lead to surprise being successful, which I think is reasonable. What I found weird is that iserith said he would not even roll for stealth, but I think hiding should be possible, even if surprise is impossible.

I would not ask for a Dexterity (Stealth) check to determine surprise because of the specific context of one PC leading the monsters to the other PCs.

 

[DEFCON 1]

I told the player that it's up to him if he wants to be stealthy or not, but if he doesn't roll then the others might get suspicious of him. So he decided to roll (and rolled a 1, lucky).

My point with the rolls was that for me, the moment someone wants to be stealthy, he rolls stealth (unless I determine it's impossible or trivial to be stealthy, which is definitely not the case here). For me the result of this roll is also used to determine if surprise is successful, but a successful stealth roll in the context still does not lead to surprise being successful, which I think is reasonable. What I found weird is that iserith said he would not even roll for stealth, but I think hiding should be possible, even if surprise is impossible.

Oh, I agree with you that I think rolling Stealth for the enemies and the PC is the correct call... because as you say, even if the party isn't surprised by them, the enemies could still gain Advantage on their attacks for being Hidden.

As far as the PC rolling Stealth, I also agree that telling the player that he should roll just to try and appear as though he was moving stealthily was the right call... I probably though would allow him to decide to move stealthily poorly on purpose (and say let him roll with Disadvantage). Heh... heck, in this situation I might've even ruled that the PC rolling that 1 might've been SUCH a poor Stealth check that I would either have the enemies automatically NOT be Surprised because they realized the PC really f-ed up so badly that something must be up... or at the very least make the PC have to roll a DEX (Deception) check to try and cover up the fact they stealthed so poorly, or else the enemies got tipped off. As the DM, I'd do that if I just thought it would be funny and really cheese the player off.