Non-detection vs Scrying

[RainOfSteel]

The sensor rules on PHB p.173 note that other forms of protection are available, such as lead sheeting. If whoever the magical sensor had located and was viewing walked into a room shielded by lead sheets, I believe it would no longer be able to view anything.

There are two ways to go from here: Either the magic sensor gets to hang out until the duration runs out, or its duration ends prematurely.

There are two ways to go from hanging out: Either it can view things while waiting, or it can't.

My personal opinion is that the magical sensor, already established, hangs out. It would also continue to be able to view the area, but it couldn't move.

In any event, I would have nondetection work the same way as lead sheeting, only the subject could walk away unseen and the magical sensor would not be able to follow.

 

[KarinsDad]

The sensor rules on PHB p.173 note that other forms of protection are available, such as lead sheeting. If whoever the magical sensor had located and was viewing walked into a room shielded by lead sheets, I believe it would no longer be able to view anything.

Except that the magical sensor follows the subject.

I think the intent of "lead sheeting" (a blatant 1E rip off of X-ray vision cannot penetrate lead) is again to protect when the Scrying spell is cast, not afterwards.

Take for example the rest of the text on that page:

Unless noted otherwise, the sensor has the same powers of sensory acuity that you possess. This level of acuity includes any spells or effects that target you (such as darkvision or see invisibility), but not spells or effects that emanate from you (such as detect evil). However, the sensor is treated as a separate, independent sensory organ of yours, and thus it functions normally even if you have been blinded, deafened, or otherwise suffered sensory impairment. Any creature with an Intelligence score of 12 or higher can notice the sensor by making a DC 20 Intelligence check. The sensor can be dispelled as if it were an active spell.

Lead sheeting or magical protection (such as antimagic field, mind blank, or nondetection) blocks a scrying spell, and you sense that the spell is so blocked.

The magical sensor is specified as an extra sensory organ. Like having a floating eye.

Then, it states that antimagic field blocks it.

It is reasonable that antimagic field blocks it:

1) when the spell is cast and
2) if the sensor goes into the AMF.

It is not very reasonable that the antimagic field blocks it if it is outside the AMF when the AMF is cast. If it gives one the same powers of sensory acuity normally possessed, how does AMF stop it when AMF does not prevent sight? That would be a lower level of sensory acuity. The divination portion of the spell once successfully cast is to see from that location.

Hence, the reason I think these protections were originally set up with "at casting time" as the intent. However, I can easily see how "once it is cast" can be read into it.


Btw, the Scrying spell itself disagrees with the text here in that Detect spells do have a chance of working through it.

 

[RainOfSteel]

I feel that if all forms of protection vs. scrying listed in the rules operate in exactly the same way, it creates no variant situations requiring further interpretations and rulings.

Thus, there is no need to differentiate AMF and lead sheeting as far as scrying is concerned.

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BTW, what is wrong with 3.x drawing on information from 1e/2e? That isn't ripping off, AFAIK.

 

[KarinsDad]

I feel that if all forms of protection vs. scrying listed in the rules operate in exactly the same way, it creates no variant situations requiring further interpretations and rulings.

Thus, there is no need to differentiate AMF and lead sheeting as far as scrying is concerned.

I do not differentiate. I interpret them both to occur at casting time, but not once the subject fails the saving throw.

Once the divination magic is successful, it stays successful until some counter magic is used against it (e.g. Dispel Magic).

BTW, what is wrong with 3.x drawing on information from 1e/2e? That isn't ripping off, AFAIK.

You misunderstood.

Not divining through lead is a rip off of Superman's Xray vision not seeing through lead. It was a 1E ripoff, not a 3x one.