I mean, just think about it. In movies, it's all about Skynet this, Skynet that... that's how it's going to happen. But in real life, it happens in a way you NEVER EVER expect. How it happens: we have a country with an extremely powerful military, yet it does not want to have boots on the ground in term of real flesh and blood soldier. So you get a situation where organization like ISIS rise up, but the country with the strong military gimps itself by not allowing itself to send soldier into battle. So you have a problem, what is the solution around the problem? Solution: killer robots! It's ingenious holy crap. Those who say "No boots on the ground"--due to disliking death of living soldier on their side, have nothing to say to kill robots. Since real people won't be dying, but robot instead. LOL, what a way around.
Lets say we make them. When we make them. This isn't a discussion about ethic. This is not a discussion about ifs. This is a discussion about it's going to happen. When it does, what should they look like? Example:
I mean, why not? why not just make them look exactly like this? we already have an idea which is popular in the movies which has made us familiar and inspired us to the idea of killer robots. Instead of making the real thing look like something else, why not just make them look exactly like something we're familiar with? if you were on the military board to design the look of killer robots, would you vote to make them look like the Terminators or something else if those were the only two options? IMO you shouldn't have any reason to make them look like anything else.
I have to say, the evolution of how killer robots happen in nature is interesting and kind of ironic. If we had every human societies in nature act like ISIS, or to more of an extend Roman/middle age/medieval time societies, with a lack of caring for life, then they'll just use real people to fight wars and kill. However, it gets to a point in evolution where some societies start to become more caring for life, thus showing restraint in the killing, and this give rise to killer robots. LOL!!! super interesting how it happens.