Tactical Challenge #4

[Dork_Forge]

It's standard for animated objects. Totally plausible for PCs to know. Would be more surprising if it turned out NOT to be vulnerable. In any case it's simple enough to kill before entering the room--how you kill it basically doesn't matter. It can't stand up to six 9th level PCs and their summons.

Plausible, but shouldn't be assumed, after all the PCs in question may have never come across animated objects before or just never learned this weakness.