And then look over at vampires—they die if you cut off their head or stick a stake through their hearts.
Actually, that's a tad off.
You have to stab them through the heart with a
wooden stake- in most of the older stories, made from one of just a few kinds of wood (ash, hawthorn and a couple others that have mystical connotations of purity and holiness)-
THEN cut off the head and stuff its mouth with garlic, a Holy Symbol or the Host.
Which, to my mind, is NOT supportive of crits & sneak attacks. That's the description of disrupting of dire magics with certain designated materials and a ritual. Stabbing them through the heart with a standard dagger 1.5B times, and they'll still keep coming back.
(I'll grant you the
modern zombie, though.)
Same goes for constructs—you can hit them in the gears or the joints or the magic power sources or whatever to do more damage, kind of like how Jason takes down Talos in the old movie "Jason and the Argonauts," or how you always see robots getting messed up by getting shot in the processor, or how video games often put "weak points" on giant animated statues, and so on.
Yes, to a certain extent.
To me, that doesn't support a blanket rule of allowing crits and/or sneak attacks. To me, that supports the existence of a Feat or some kind of difficult skill check to determine whether or not a PC can gain the benefit of a crit or SA. While most humanoid creatures will share a certain similarity of internal organs and what all, each construct (or type of construct) will have unique weak spots. Talos' weak spot was in his ankle, yes, but that doesn't mean that EVERY Iron Golem's ankle is similarly vulnerable.