Zargon make the call of course, and especially when you're mixing expansion elements together situations of ambiguity are bound to arise (though of course the hero collections were theoretically designed to be used anywhere you see fit, including future quest expansions) where he has to rule on it.
The Explorer's Trapsmith alerts of adjacent traps, but it's clear that Wandering Monster traps fit under their own category of "undetectable" traps. Just like how Potion of Vision (MOTM) doesn't let you see such traps (only "normal" traps), I would say they intend them to remain undetected by that ability. It certainly would make the Explorer more powerful/useful if he could see such traps!
I agree... Wandering Monster traps function differently than Treasure deck Wandering Monsters. With a WM Trap, a hero can still perform an action (such as attacking them) after being attacked (so long as they haven't done their action yet) but otherwise their turn ends. Whereas a Treasure deck WM occurs after the treasure search action, so all the hero can do after that is his movement (if he hasn't used it up already, that is). In contrast, the WM trap, according to AH, stops the hero from moving, even if he had movement left.
The WM trap can't "miss" the monster always appears to attack... the only exception being how the Companion App handles Knight's Challenge, where the monster could attack the Knight in the same corridor even if he was far away, in theory the Hero could keep moving if he had squares left...? The Knight's Challenge skill card only mentions rooms (even in the ROTDM version), but the App lets you use it in corridors (the App has some differences from the rules as written we've seen... sometimes clearly intended as an amendment, other times changed due to limitations of the programming and other times inexplicably like its own errata).
Normal traps end the triggering hero's turn once sprung (unless the trap "misses" as is possible with a Spear Trap), regardless.
We've used the Explorer, but not extensively enough to encounter this specific situation. As Zargon I'm a little more lenient when it comes to WM traps, I say something like the searching hero gets an uneasy feeling in this area (without pointing to the specific square) without letting them disarm it of course. So if I'm being consistent I'd probably say the same of the Explorer, but maybe I'd give the warning as they enter the room/corridor so as not to spoil the exact location of the WM trap. I also utilize the (draft notes from 1992 inspired) "blind trap jumping" mechanic. In theory I should probably allow the hero to jump a square and if it was a WM trap, avoid it that way, so I'm not going to go out of my way identify the precise square until it's too late... but that's my burden to bear with my own house rules.
