How to determine surprise when only part of a side is stealthy?

Question

Here’s the basic rule for Surprise (Player’s Basic Rules, p. 69):

If neither side tries to be stealthy, they automatically notice each other. Otherwise, the DM compares the Dexterity (Stealth) checks of anyone hiding with the passive Wisdom (Perception) score of each creature on the opposing side. Any character or monster that doesn’t notice a threat is surprised at the start of the counter.

I’m not sure how to interpret that last sentence.

For example, suppose that the players try to sneak up on on some monsters, so they roll Dexterity (Stealth) checks. The thief and the champion both roll 14, but the evoker only rolls 9. The DM compares this to the monsters’ passive Perception: a cyclops with 8, a dire wolf with 13, and a giant owl with 15.

The cyclops doesn’t notice any threat, so it’s surprised. The owl notices all the threats, so it’s not surprised. But what about the dire wolf? It notices the evoker but not the rogue or the champion. Which is correct:

• The dire wolf noticed a threat (the evoker) so it’s not surprised.
• It didn’t notice a threat (the rogue and champion) so it’s surprised.

If the former is true, could the rogue and champion take advantage of the group check rule to help the less-stealthy evoker hide from the dire wolf? Group Checks (Player’s Basic Rules, p. 59):

To make a group ability check, everyone in the group makes the ability check. If at least half the group succeeds, the whole group succeeds. Otherwise, the group fails.

Group checks don’t come up very often, and they’re most useful when all the characters succeed or fail as a group.

An earlier question covers a couple of related situations, where a rogue sneaks up separately from the rest of the players, or where all of the monsters use a single group Dexterity (Stealth) roll, but not this case where all of the players try to sneak with different rolls.

Answer 1

There are two ways to interpret that sentence, and it hinges on a weirdness of how English uses the indefinite article.

Any character or monster that doesn’t notice a threat is surprised at the start of the counter.

The usual interpretation of "a threat" here is that it means "one threat". If that is the correct reading, your question is the result. Is it correct though? This meaning would require that surprise is a relationship between two individuals, so that the dire wolf could be surprised by the rogue but also not surprised by the enchanter.

Is this how surprise works? It turns out, no:

If you're surprised, you can't move or take an action on your first turn of the combat, and you can't take a reaction until that turn ends. (PBRv0.2, p. 69)

Surprise is not a relationship between two entities, it is a state of a single entity. It's impossible to be surprised by one opponent but not surprised by another.

Is there another way to read that sentence about "a threat" that makes surprise sensible as a state? As it turns out, yes.

"English is funny that way"

Another use for the indefinite article, which looks identical to the "one threat" meaning, makes the sentence in question

Any character or monster that doesn’t notice a threat is surprised at the start of the counter.

mean any threat at all, not just one. If this meaning of "a threat" is how it's being used, then that means only creatures who notice no threat are surprised.

Because this reading is perfectly normal English, but ambiguous, we need to confirm the reason by looking for clues in the surrounding text. That confirmation is in the definition of surprise we looked at above: being surprised means being completely surprised, which only makes sense if it happens when no threat is noticed.

So the dire wolf is not surprised, because it did notice a threat, as opposed to not noticing a threat. (See how that makes sense put that way?)

On the plus side, the champion and the rogue don't need surprise to have advantage on the dire wolf, because that doesn't rely on surprise, but rather on being unseen, and being unseen is a directional relationship, not a state.

Answer 2

RAW: Your first bulletpoint is correct, the 2nd is wrong.

There are two ways to play this, the first is RAW as I understand it and the second is a houserule which I believe supports the spirit of the rules.

Option 1, RAW: If a creature can detect any enemies it is not surprised

As the surprised section states:

Any character or monster that doesn’t notice a threat is surprised at the start of the encounter.

I can see where the confusion might come it, you are possibly interpreting "a" as meaning a specific threat, whereas I believe "a" is used in this case to mean "any" threat. Even if they can't see the Rogue or the fighter, they noticed other guy and are on guard for attacks. As such they are not surprised.

Option 2, Houserule: Treat all stealth rolls as partywide checks.

The DM decides who might be surprised.

This simple sentence preceding the explanation of comparing passive perception vs. stealth checks leads me to believe that DM Fiat is supported in this case. As such I suggest partywide stealth checks.

If the majority of the party would beat the passive perception of the monster's passive perception then the party would get a surprised round against said monster. For this to work though it needs to cut both ways and monster stealth checks should equally work if they beat the majority of the party's passive perceptions.

Answer 3

The whole rules passage is important to gain an understanding of what I believe the RAW intend. Points 4 and 5 in the notes below the rules quote are the key ones.

Player's Handbook p189

A band of adventurers sneaks up on a bandit camp, springing from the trees to attack them. A gelatinous cube glides down a dungeon passage, unnoticed by the adventurers until the cube engulfs one of them. In these situations, one side of the battle gains surprise over the other.

The DM determines who might be surprised. If neither side tries to be stealthy, they automatically notice each other. Otherwise, the DM compares the Dexterity (Stealth) checks of anyone hiding with the passive Wisdom (Perception) score of each creature on the opposing side. Any character or monster that doesn’t notice a threat is surprised at the start of the encounter. If you’re surprised, you can’t move or take an action on your first turn of the combat, and you can’t take a reaction until that turn ends. A member of a group can be surprised even if the other members aren’t.

Splitting it up into bullet points:

1. The DM determines who might be surprised
2. If neither side tries to be stealthy, they automatically notice each other.
3. Otherwise, the DM compares the Dexterity (Stealth) checks of anyone hiding with the passive Wisdom (Perception) score of each creature on the opposing side.
4. Any character or monster that doesn’t notice a threat is surprised at the start of the encounter.
5. If you’re surprised, you can’t move or take an action on your first turn of the combat, and you can’t take a reaction until that turn ends
6. A member of a group can be surprised even if the other members aren’t.

Point 1: Whatever else, in the end the DM decides who might be surprised and has the rules below applied to them.

Point 2: If no one is stealthy everyone automatically notices that there is "a threat". No one is surprised, everyone gets to act on their first turn of combat. See Point 5 below for the required interpretation of "a threat".

Point 3: If at least one person tries to hide then everyone on the opposing side has to compare their passive Wis(Per) to the hide skill roll(s). It does not have to be everyone in a group trying to hide for this step to be important and necessary as surprise is not the only outcome of a successful hide roll. For instance it would determine who a rogue is successfully hidden from at the start of initiative, even if they see a fighter who is not hiding.

Point 4: Anyone who does not notice "a threat" is surprised. See Point 5 below for the required interpretation of "a threat".

Point 5: If you are surprised then you can't move or take an action in your first turn of combat. This means that "a threat" must mean any threat at all or the RAW are nonsense (which they aren't). If you see "a threat" of any kind you can and will react and do things, so "a threat" referred to in Points 2 and 4 must mean any threat at all. Therefore you are only surprised if you see nothing of the opposition, whatever that is (it could be a load of traps rather than people). But as noted in Point 3 just because you aren't surprised does not mean you have noticed every threat.

Point 6: Each member of a group can be independently surprised. Bummer.

The key thing here is that the term surprised used in the rules here is a "condition", not an adjective. A character has the surprised condition if Point 4 is the case, i.e. they have not noticed "a threat", any threat. If they have noticed "a threat", any threat, then they are not surprised. It does not matter how many threats there are, someone only needs to notice one not to have the surprised condition.

Used as an adjective, i.e. not RAW just a story description, they might be surprised by the rogue jumping out of the tree but that is not the surprised condition unless Point 4 is the case.

In addition to the above there is a phrase used in the rules "If you’re surprised, you can’t move or take an action on your first turn of the combat". The key bit is "your first turn of the combat" meaning that it is possible for someone to be surprised even after the fight, or whatever, has started. They would somehow need to be unaware of any threat for some reason. Perhaps an illusion, deafness and blindness, reappearing from a benignly cast "disappearing" spell? I've not tried to create exact examples of this (anyone?). I can see possibilities around teleportation too...

Answer 4

Hmmmm tricky, BUT - if you follow the exact letter of the wording, it seems extremely clear the rule (whether it was intentional or not).

the rule does not say "Any character or monster that doesn’t notice ALL threats is surprised at the start of the encounter."

It does not say: "Any character or monster that notices a threat is NOT surprised at the start of the encounter.

It says: "Any character or monster that doesn’t notice a threat is surprised at the start of the encounter."

Thus you can ask a very simple clear yes or no question.

In the case of a mixed stealth party where some are noticed and some are not.

1. Was there a threat? Yes. (several actually)
2. Was a threat not noticed? Yes, the stealthed rogue was a threat and it was not noticed.

The condition is fulfilled, (a threat was not noticed) and therefore the opponents are surprised. There is nothing in that rule that says, if ONE threat was noticed but othter threats WERE noticed then there is no surprise. Its actually a very efficient sentence.

I just did some research and this has been argued extensively in other forums. They get very situational and try to describe why an opponent would be surprised just cuz it couldnt see one out of 5 targets. I think the concept the designers were going for was distraction and ambush. When you are focused on one opponent and another comes at you sideways, you are surprised and now even the one you were focused on gets to take advantage.

Just my thoughts.