Will Detect Evil Reveal the Swap Trick?

[Xihirli]

If Redcloak uses Detect Evil to trace where Xykon’s been, won’t he be able to tell that the trail ends right at the magic line every time?
Then Team Evil could find backstage.

[Fyraltari]

If Redcloak uses Detect Evil to trace where Xykon’s been, won’t he be able to tell that the trail ends right at the magic line every time?
Then Team Evil could find backstage.

The swap-overs show the tunnel they teleport to when looked at from the outside. We have no way to know if the magical aura left off by Xykon can be perceived through them like light can.

[FujinAkari]

Yeah, it depends if Redcloak uses the trick to see which tunnels Xykon hasn't been inside and explicitly goes there, or if he opens one he knows Xykon HAS explored and will almost certainly note that the trail of evil doesn't go very deep inside the tunnel

[Psyren]

No way of knowing, we're well outside RAW territory with that trap. The DM author could reasonably go either way.

[ORione]

When Redcloak looks through the tunnel, he'll see through the portal, to a tunnel that Xykon has been through. It won't help.

[Jay R]

When Redcloak looks through the tunnel, he'll see through the portal, to a tunnel that Xykon has been through. It won't help.

Yes, that's what he will see. The comics show us that that's how sight works. But does the detect evil spell work that way? Specifically, it has a 60 foot range. If the teleport is more than 60 feet, then the aura on the other side is out of range.

[Dame_Mechanus]

The big question is whether or not Redcloak will look inside the doors. The phrasing of his statement is pretty clear: he wants to see which doors Xykon has actually been to. Logically, the doors Xykon has been inside are ones he assumes he no longer needs to search, because he believes that it's a very real possibility that the dungeons are producing monsters faster than normal in response to the increased pace of their search and the idea that they must be getting close.

So before asking "will he see the trail continuing past the swap," I think a better question is "will he open the doors that the trail indicates in the first place?"

[Laurentio III]

If the teleport is more than 60 feet, then the aura on the other side is out of range.
The teleport is a couple feet away from the door. Really no reason to dig further.
But as the teleport is actually a gate, we assume all vision spell would just go through it unnoticed. Reasoning:
• the gates has been created to con adventurers. If a simple first level spell could reveal the trick, they wopuld be garbage;
• Redcloak entered one in full investigation mode. Anything easy to notice would have not escaped his attention.