Any games ever have enemy AI notice missing guards?

I finally got Thief (the newest one) to work properly on my PC, and I am really digging it. One thing I really like is how the enemy AI notices stuff like opened containers that were not previously open, such as locked chests or safes, making closing everything behind you important to mask your activities. Got me thinking if there are any games that also has AI that notices missing guards. I'm not talking about them coming upon a knocked out buddy or noticing you knock someone out, but that they realise during their patrol route that there are no longer any ally guards where there should be some.
Anyone know of any games that even tried incorporating such a mechanic? I imagine that it would be a programmer's nightmare.

Metal Gear Solid, kind of? I know that's a factor in these games somehow.

I can swear there was at least one game that had guards that would say something to the effect of "I thought there was more of us..."

It could've been the Batman Arkham series, I know those comment on it.

@video_game_king: Guards in 2 (and maybe onward) would comment if a soldier didn't check in via radio for awhile.

@somedelicook: It seems like the Batman games sort of did that, the guys would come across bodies and react to that, but it seemed like every once and a while if you did a take down that would 'hide' the bodies (which wasn't many, actually maybe it was just the one where you string them up to the statues) at some point they would remark to how there used to be more of them or the Joker would call in and warn them.
So it half counts, almost, maybe a quarter.

In Dishonored the guards would comment about an area that is supposed to be patrolled, and then take on the missing enemy's route.

Guards in Chaos Theory sometimes notice

Well, in Metal Gear they'll call on the radio, and if no one answers they'll send in back up.

As mentioned above: Metal Gear Solid 2 had guards that would periodically report in via radio. If they failed to call on time a search group would be sent in to find them.

And In the Arkham games (At least in Asylum and City, can't vouch for Origins) if you knock out any patrolling guard in the stealth sections of the game the Joker / the villain of the moment, will chime in on the loud speakers and alert everyone starting a search for the missing guy and Batman. This is not exactly the same thing. More of a caution mode so to speak rather than the ai dynamically reacting to missing allies.

Did Far Cry 3 have a system like this? I could have sworn the guards had little random conversations with each other from time to time and would react to missing guys with "Where'd that guy go?" and start looking for they're allies.

Arkham Asylum/City make the AI function differently depending on how many guards are left in the room.

@csl316 said:

It's been a long time since I've played any of those games, but I seem to remember that if the back up team found the downed guard, all they'd do is wake him up and go back to their business, rather than, you known, wondering why their buddy was unconscious in the first place, or asking about the gigantic tranq needle that would have been sticking out of his neck.

Honestly, it's probably for the best. If enemies reacted realistically to this kind of stuff, you'd pretty much be forced to ghost the whole game, which has the potential to get real frustrating, real quick.

Yeah, that's right, I totally remember that. Or commenting on how a power source suddenly went out. You'd think that on a higher difficulty setting they'd program the guards to check it out, but I don't think they did.

That is definitely true, frustration would set in pretty quick. But I think that these things could also open up opportunities for better difficulty settings, that affect the game beyond just enemy health/damage.

the dumber the better, because if they are too smart then it's like playing with Bots who see through walls and auto aim