D&D 5E Assassinate

[redrick]

why would you need to make a stealth check if you are magically concealed AND no one is looking for you?

Because being invisible only accounts for one of the 5 senses. Everybody knows exactly where the invisible knight clomping through a room in a suit of plate armor is.

Being invisible through magic is no better and no worse than being totally concealed by mundane means when it comes to determining whether or not you are hidden.

 

[epithet]

why would you need to make a stealth check if you are magically concealed AND no one is looking for you?

If you're invisible, you can make a check with advantage to see if you're quiet. If you're concealed by an illusion of someone else, however, you should use charisma (Deception) with advantage, opposed by 'passive' insight. It has the same effect--you're undetected, you get surprise.

 

[GMforPowergamers]

Because being invisible only accounts for one of the 5 senses. Everybody knows exactly where the invisible knight clomping through a room in a suit of plate armor is.

Being invisible through magic is no better and no worse than being totally concealed by mundane means when it comes to determining whether or not you are hidden.

in a room full of people, or an open air market you would not hear a single person, and if you have no reason to expect an invisable person than it as you said 'like a perfect natural concealment' I rule if you are behind a rock and out of sight completely there is no roll either... after all if they can't see you and aren't looking for you, you are hidden

 

[GMforPowergamers]

If you're invisible, you can make a check with advantage to see if you're quiet. If you're concealed by an illusion of someone else, however, you should use charisma (Deception) with advantage, opposed by 'passive' insight. It has the same effect--you're undetected, you get surprise.

but if no one is listening for you, or ambient noise is greater why do you have to be silent?

 

[redrick]

If you're invisible, you can make a check with advantage to see if you're quiet. If you're concealed by an illusion of someone else, however, you should use charisma (Deception) with advantage, opposed by 'passive' insight. It has the same effect--you're undetected, you get surprise.

There's no inherent advantage conferred to stealth by invisibility. Who is harder to notice, the invisible person walking across a room in front of you (making footprints and footsteps, knocking things over, breathing, rustling fabric, etc), or the "visible" person hiding around a corner?

Total concealment is, under most circumstances, a prerequisite for hiding. How you achieve that total concealment is irrelevant, unless noted by a particular special feature or ability. The advantage of being invisible is that you can always attempt to hide, because you are always, visually, concealed. (And you get advantage on your attack rolls and impose disadvantage on attack rolls against you, which is also pretty damn useful.)

As for the case of [MENTION=67338]GMforPowergamers[/MENTION]'s bard and surprising a warlord by appearing to be somebody that he trusts? Absolutely. The warlord is unaware of a potential for combat. Whether this obtained through "stealth" or through other, more devious means is irrelevant. Of course, the bard has to keep the illusion up until the last possible moment.

As for multiple attacks? The way most people seem to be ruling surprise here, yes. You are no longer surprised at the end of your turn on the round in which you were first surprised. So, until that point, you are surprised, which means you'd yield Assassinate to a bard-Assassin, and, of course, you can't move that round.

Of course, the bard-Assassin would have to win initiative, otherwise, the warlord is no longer surprised once his turn is over and the bard is able to act.

(As I run things, which not all agree with, if the bard was able to strike from hiding, and in no way give up the game until the blade actually strikes or misses the warlord, that attack would be allowed to go first, but any further attacks do to multi-attack would happen in normal initiative order. But that's kind of my house rule, I guess.)

 

[redrick]

in a room full of people, or an open air market you would not hear a single person, and if you have no reason to expect an invisable person than it as you said 'like a perfect natural concealment' I rule if you are behind a rock and out of sight completely there is no roll either... after all if they can't see you and aren't looking for you, you are hidden

In this case, any advantage or automatic success is being conferred not by the invisibility, but by the obstruction of the other senses. It all comes down to the situation. And, sure, if you think there is no reasonable way for anybody to notice your invisible character, have it.

In my opinion, an invisible person walking across a crowded market is more likely to draw attention than a visible person. There's nothing unusual about somebody bumping into me in Grand Central Station, but when something bumps into me and I don't see anybody there? I'm gonna make a commotion. There are plenty of things that could go wrong in that scenario, and success is by no means guaranteed for a player character.

 

[Paraxis]

why would you need to make a stealth check if you are magically concealed AND no one is looking for you?

Because you still make noise, leave foot prints, have an odor, are moving around possibly bumping into things, all kinds of things that make it so unless you take an action to be sneaky people can tell you are in the general area.

 

[Hriston]

You're conceptually off there. Sound drops by the square of the distance, not doubling of the distance. While the dB scale is logarithmic and so takes that into account (again, roughly), by applying the drop over doubled instead of fixed distances you're negation much of the purpose of using the db scale. I'd halve the distances you have calculated and that should be a decent ballpark.

I'm not sure what you mean by fixed distances. The reason I'm using doubled distances is that every resource I've consulted says the sound pressure level is reduced 6dB for every doubling of the distance from the source of the sound. This takes the inverse-square law into account because we are using decibels, as you pointed out above, so I'm not understanding why you're suggesting fixed distances or what those distances would be.

Generally, if you get the result that you can hear someone singing loudly without amplification clearly from two football fields away, you've done something wrong. On a dead calm day with the wind in the right direction and no other sounds, you could probably hear something, but not tell what it was.

For clarity, my point wasn't that you could hear them clearly, but that under ideal conditions you could hear something, probably recognizing it as a voice, and know that someone was there.

Here's an example of my work:

Loud singing is measured at 75dB from 3' away from the source, so applying a 6dB drop per doubling of that distance you'd end up with a sound pressure level of 33dB at 384', and 27dB at 768', both of which are close to the sound level of a whisper measured from 6' away (30dB).

For ambient noise I'd use disadvantage on perception.

 

[Hriston]

I've realized that it's pointless to continue this conversation without directly addressing what I see as the basic misperceptions upon which your reasoning is based.

... the effects of surprise for those guys is that they... are vulnerable to auto-crits from Assassinate until they notice a threat...

There is no rule that says you become unsurprised, or that surprise ends, when you notice a threat. It doesn't say that anywhere, and it simply isn't true.

... you are vulnerable to auto-crits from Assassinate all the while that you don't notice a threat, and are not vulnerable to auto-crits all the while that you do notice a threat. If you start combat surprised then you become 'un-surprised' when you notice a threat...

Your assumption that being surprised is the same as not noticing a threat is oversimplified. Please, show me where it says you become unsurprised when you notice a threat. You can't because it doesn't appear in the text.

If you start combat 'surprised', then notice a threat (because the attacker/assassin runs into the open) before your first turn, you still can't do anything on your first turn even though you are no longer surprised!

This shows the flaw in your argument, because it ignores the definition of surprise given in the text:

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.

This only applies if you are, currently surprised. Your interpretation amounts to you being surprised and not surprised at the same time.

As explained above, if you were surprised at the start of your first round of this combat, then you suffer the 'cannot act' penalty on your first turn, and that penalty has already been caused at that point. That 'cannot act' penalty doesn't go away if you notice a threat in the meantime; no rule says that!

Just like no rule says you are no longer surprised if you notice a threat in the meantime. That's because for you to suffer the penalty, you must be surprised. It follows that if you are surprised, then you must be suffering the penalty.

... no rule says that 'being able to react' = 'no longer surprised'...

If you are not surprised, then why are you unable to react?

Just because surprise was determined at the start doesn't mean it isn't true later also.

This is your other misconception. The truth is no creature is ever mentioned being surprised at any other time than at the start of the encounter. If you want to impose a penalty that resembles surprise at other times throughout combat that would be your houserule.

'Haven't noticed a threat' = 'surprised.

No it doesn't. It equals surprise at the start of the encounter.

 

[epithet]

but if no one is listening for you, or ambient noise is greater why do you have to be silent?

You clearly don't. If your invisible character is stalking a target in a crowded marketplace, though, I would replace the stealth check with an acrobatics check to avoid bumping into anyone in a conspicuous way. The DC wouldn't be very high unless it was Christmas shopping season.