On the topic of weird fridge logic in RPGs, I notice that you can find/buy/steal a lot of swords. Some questions:
1) Do they come with a scabbard?
2) Why don't you ever have to clean them, if you're stabbing and slashing everything that moves?
3) How is it that you can carry around 99 swords without a freaking semi truck to store them in?
4) If they've been sitting in a chest in an ancient underground castle for a million years, why aren't they so rusty that they break the first time you hit something with them? Especially a robot?
5) How does hitting a robot with a sword damage it?
6) Seriously, how does using a sword to hit a robot from a supposedly technologically advanced ancient civilization damage it? It's presumably rust-proof, if it held together for thousands of years well enough to still be functioning.
Now, on the subject of ancient advanced civilizations' robots that are still running around (thinking specifically of the Sentries in Final Fantasy 1)...
1) What kind of super magical fuel component does this robot run on? It can't be electricity (even that generated by solar power), as the circuit paths would have rusted out a long time ago.
2) What kind of super magical metals could have been used to construct a robot that wouldn't have rusted so badly (in the zillion years it's been just wandering around) that the robot would no longer be able to move, much less attack?
3) Returning to the solar power thing, if the robots were solar powered (the only way I can think of that such a device could have functioned independently so long after its creators have disappeared), then why can you only encounter them indoors?
Scabbards are hard to animate (in 3d at least) so it seems no sword needs one. I really wish I think it was a video on the witcher had not mentioned that as it became one of those "can't unsee" things for me.
4) I will give a sharp might not be well honed any more but I am willing to write that off with 2)'s "the same reason you do not see them go to the toilet*". A million years might be an odd one**, I am not entirely sure of the mechanisms that operate on such a timescale, but a few thousand years for the proper steel alloy is nothing, get something more suitable than steel (basic carbon steel really is awful for oxidation/corrosion, though it does make nice sharp things and said sharp things have tended not to be needed to last 100 years as much as the following few battles).
*you may do in some games, I tend to avoid the stranger offerings though.
**this is an interesting one to speculate upon and with metal manufacture having not really operated on this level there is not much here, more general chemistry does have some of this but I am not sure how applicable it will be to metals, or possibly inorganic composites. Of course Iron 56 being the most stable element as far as nuclear "chemistry" goes might change a few things here.
5) One does have to wonder what kind of super self repairing machines and crazy alloys/forging methods used would lead to this. On the other hand engineering is a tradeoff in most cases so protection from corrosion does usually lead to deficiencies in some other area, very likely including strength (tensile stiffness, torsion, bending, shear....). Moreover "ageing" is actually a well documented thing in various metal alloys, Aluminium-copper having a process calling ageing and things like nitrogen fixing in steels. Overdoing it, something I imagine to be quite possible over the thousands of years, does make for serious changes to the strengths of metals. Likewise if these robots were not being held at near absolute zero (though that would be another problem) you would probably also get some kind of diffusion of elements, this tends to be more of a high temperature thing (see creep) but low temperatures also have some stuff.
Equally physics is still physics and though a sword might often be more of a cutting or stabbing weapon we tend to see the rather large greatsword in games: f=ma is not noted for being discerning about what it applies to.http://archaeologyonline.net/artifacts/iron-pillar
might also be worth a look.
1) Assuming magic is not an answer then I would guess some kind of nuclear reaction, one coupled with a proper sleep mode. Alternatively a seriously low entropy source of some form that could be "unshielded" to gain energy, of course that leads us right back into magic territory.
2) I do have to be the type of insufferable bastard to point out rust is an iron based thing, however pondering oxidation or corrosion (whichever applies in this case) is worth considering.
3) Wireless power transmission at distance is possible.
Anyway enough late night science for a discussion that was not calling for it, the possibility of a materials/metallurgy discussion was too much to resist though.