How do dream characters behave in relation to normal people?

I've only had one (very brief) LD and I just got curious. Lets say that I was in a room with two dream characters and I took out a gun and shot one of them. Would the other react accordingly (A.K.A freak the hell out) or just stand there and go "oh you shot that guy, huh?". I'd just come to imagine they are like NPC's in a video game. Like in Grand Theft Auto you just walk around with a rocket launcher and nobody pays you mind, and talking to them would be like that hologram from I, Robot where if you say something it wasn't programmed to respond to it just gets confused. I'm probably horribly wrong but I'm curious to see.

I did not have Lucid Dreams in a long time, but read alot about it. Anyway take what I write here with a grain of salt :p

I think it depends heavily on how you expect them to react and/or how Lucid you really are. If you're fully lucid and also thinking you control all things and you can do whatever you want its your dream, then I think they would act like NPC's no one pays you mind when you're running amok just if you expect it to be so! The other way around, maybe if you don't have a preconception about how they will react, you can never forecast it? Just my opinion, but maybe one with more experience in LD can say something more about it and prove me wrong :-)

Well after just having a lucid dream I can say at least in this one they did. My brother was still the stubborn dude he is in real life.

It's all random. You can never know how exactly will they react. They can freak out, don't care at all, ask you to shoot them too, ect....
What Oceandrop said is also true, if you expect the DC to act surprised for example, then it'll act surprised.

The dream world has no set things like this, that a DC will behave the same way everytime... it's everchanging :)