D&D 5E Phase Spiders and Surprise

[MerricB]

No because when the phase spiders emerge in the PC's area they are not hidden and thus automatically notice each other.

Surprise: 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.

Wrong.

They are stealthy by virtue of being on a plane where they cannot be seen or heard (but they can see the characters).

Consider an Rogue/assassin. He surprises a monster (having used Stealth successfully). In the first round of combat, he wins initiative and runs screaming at the monster in full line of sight and attacks. Is the monster still surprised? Yes. Unlike Hidden, the state of surprise does not end when foes become visible. It ends after the surprised creature takes its first turn.

 

[Plaguescarred]

You can certainly rule that the spiders can't start combat until they phase to the material plane, but there's nothing in the rules text that says so.

Sage Advice clarified that actions aren't taken just prior to initiative, but after. http://dnd.wizards.com/articles/feat...-november-2015

"If anyone is surprised, no actions are taken yet. First, initiative is rolled as normal. Then, the first round of combat starts, and the unsurprised combatants act in initiative order."

The situation is not really that different from a case where the spiders are invisible and have made excellent stealth rolls.

Wether it's invisible or not doesn't change the fact that it can't be interacted with.

Yes, because perception is not a direct interaction.

It is a direct interaction it's a contest directly between two creatures!

Imagine that the situation is reversed, the players have managed to become ethereal and want to abush a group of unsuspecting enemies on the material plane. You would not permit this?

It would work the same wether it's monsters or PCs.

 

[Imaro]

The ethereal plane, deep or border, is still a different plane of existence that doesn't allow interaction with the prime material plane even if sight is possible to it.

Even if it's the only form of interaction that can take place... Isn't sight a form of interaction?

Not because i can see you through walls or in the distance via clairvoyance or ethereal border when i take the Hide action and you can't notice me yet, that when we meet i will automatically surprise you because you couldn't notice me and i could when i took the Hide action is what i was saying.

PHB pg. 189
Any character or monster that doesn't notice a threat is surprised at the start of the encounter...

Since it's impossible for the characters to notice the spiders on the ethereal plane... but they can themselves be noticed by the spiders it seems that yes the spiders would have automatic surprise.

Note: It says encounter not combat...

I disagree with you creatures being on seperate plane of existence considered present. Like i said DM can always rule it this way if he want but automatic surprise with no chance of noticing enemies are just gotchas.

Huh? What does "present" have to do with it. If a combat can be initiated... then the various sides can be surprised or have surprise.

EDIT: You can claim it's a gotcha but I think that's the point... you do realize there are also some creatures who get automatic surprise usually through the false appearance trait...right?

 

[Imaro]

Sage Advice clarified that actions aren't taken just prior to initiative, but after. http://dnd.wizards.com/articles/feat...-november-2015

"If anyone is surprised, no actions are taken yet. First, initiative is rolled as normal. Then, the first round of combat starts, and the unsurprised combatants act in initiative order."

So... surprise is determined before actions are taken... I'm not understanding how this supports your assertion? If the spiders aren't noticeable before combat starts... they have surprise. Everyone then rolls initiative and the spiders act in the first round of combat...

 

[Mercule]

[MENTION=6701422]Plaguescarred[/MENTION], you're overthinking this. What makes narrative sense?

If the spiders are aware of the PCs and the PCs aren't aware of the spiders, then the PCs are surprised, regardless of fiddly wording. If one of the PCs had see invisible running, he wouldn't be surprised. If he could somehow alert the other PCs to the presence of the spiders before they phased in (not opining on how that works without actually starting combat, but players have a certain creativity to them) then there'd be no surprise.

Heck, if the PCs all had see invisible running, there's an outside chance they could turn around and surprise the spiders by using a Deceive check to make it appear they were clueless -- but only if your GM allows surprise for such things (which I do).

Regardless, surprise is an extremely subjective thing. You can paint broad strokes around it, but there aren't rules for every possible situation. I'd say that the spiders are likely to have surprise.

 

[Plaguescarred]

Consider an Rogue/assassin. He surprises a monster (having used Stealth successfully). In the first round of combat, he wins initiative and runs screaming at the monster in full line of sight and attacks. Is the monster still surprised? Yes. Unlike Hidden, the state of surprise does not end when foes become visible. It ends after the surprised creature takes its first turn.

I don't really see the relation with your exemple yes the surprise once established remain until your first turn even if stealth doesn't last it's not debated.

What's problematic to me is allowing Stealth to be contested against Perception of creature on a different plane and taking actions before initiative.

 

[Sorcerers Apprentice]

I don't really see the relation with your exemple yes the surprise once established remain until your first turn even if stealth doesn't last it's not debated.

What's problematic to me is allowing Stealth to be contested against Perception of creature on a different plane and taking actions before initiative.

How would you resolve the situation where an ethereal wizard is attemting to sneak past a sentry on the material plane who is wearing a Robe of Eyes?

And what actions is it you think are happening "before initiative"? in the spider surprise scenario?

 

[Plaguescarred]

So... surprise is determined before actions are taken... I'm not understanding how this supports your assertion? If the spiders aren't noticeable before combat starts... they have surprise. Everyone then rolls initiative and the spiders act in the first round of combat...

They are not noticeable because they can't even be perceived.

Yeah i guess an encounter can still occur between creatures on different planes but i still think it would need to take actions on it's turn and thus not be hidden anymore when phasing out so Stealth advantage would be lost.

 

[Plaguescarred]

How would you resolve the situation where an ethereal wizard is attemting to sneak past a sentry on the material plane who is wearing a Robe of Eyes?

I'd treat it just as if they were on the same plane since both can do the contest.

And what actions is it you think are happening "before initiative"? in the spider surprise scenario?

Ethereal Jaunt's bonus action.

But i agree with you if taken on it's turn it would simply loose Unseen & Attackers benefits unless it can remain hidden somehow upon emerging on the prime material plane.

 

[Imaro]

They are not noticeable because they can't even be perceived.

Yeah i guess an encounter can still occur between creatures on different planes but i still think it would need to take actions on it's turn and thus not be hidden anymore when phasing out so Stealth advantage would be lost.

But surprise has been determined prior to this... and the characters are surprised which means they do not get to act in the first round. Whether the creature is no longer hidden or not at this point is irrelevant because surprise has already been established. The spiders then can act in the first round while the surprised characters are unable to. It has nothing to do with the spiders staying hidden but that the reaction of the characters is slower (unable to move or act in the first round) because they were caught off guard.