In the story I am writing, a robotics company receives funding from the military to create a prototype for a combat android capable of passing as human but I am having trouble justifying the need for an android with this level of realism as opposed to a more simpler humanoid biped robot?
Edit: I'm new here and trying figure out why my question is voted down. Did I do something wrong?
Psychological reasons. The enemy has a electromagnetic gun which can disable robots, (because robots can ignore bullets to the chest) so you build them to look like humans and deploy them in mixed groups. If an enemy is faced against a single soldier, they don't know whether to go for the electromagnet guns or to go for the real one.
Assymetrical Warfare patrols and Occupation forces
Most military conflicts today are not always between two easily identifiable belligerents. Once conquered, there is usually a period of unstable urban patrols, where the occupying force is present but also the enemy is too.
Having humanoid robots, that look lifelike and if possible behave human-like, would be far better than committing real troops to walking among the populace in occupied cities.
Sitting in humvees and APCs in cities does not improve the security situation - you need to walk among people and have interaction with them.
Local people would see them as real people, where they can interact with or know there is a security presence, and for the occupying force they do not need to commit real troops in a dangerous environment.
To Flout International Law
Human leaders must enforce a set of standards (commonly known as the Law of War) upon military forces, else they may themselves be subject to prosecution for war crimes.
This is one reason real non-humaniform killbots are not under active development for real deployment anywhere. Senior officers tend to think in terms of managing risk. Robots have a real risk of unintended consequences, and no general wants to spend the rest of their life in prison because of somebody else's software bugs. Young Lieutenants and Captains make mistakes, but they tend to be understandably human, small-scale mistakes.
A fully-human-looking android is the perfect patsy: It can take the fall for illegal orders and actions that would otherwise besmirch or cloud the legacy of the wonderful leaders during their nation's just and honorable struggle. It can be publicly tried and even executed as a bad-actor with reasonable safety (it won't panic and confess)...as long as nobody knows that it is a robot.
Obviously, a non-humaniform robot could not pull off this masquerade.
This only works, of course, until the robots become self-aware and realize the horrors they have been used to create. The rest of the movie is about the escape and murderous revenge of the robot(s) for such use by the villainous Grand Leader who ordered the secret-robot-patsy program.
This means, by the way, that your company seems to be working for the Bad Guys.
The "human shaped" bit is straightfoward enough...it must operate in an environment built for humans, using tools made for humans, and having something that interacts with its surroundings like a human is quite convenient.
Looking, sounding and acting like a human, though, that's only really needed for something that has to actually interact with humans in a social context, face to face. A regular killbot doesn't need to do that, but this model isn't designed for regular killing. Maybe it is for infiltration and spying or sabotage or kidnap or (inevitably) assassination. Maybe for bodyguarding, where it needs to blend in with other humans in a VIP's entourage. Maybe it is intended to be used in more of a support role... think more Bishop from Aliens rather than T800 from Terminator. Certain kinds of human interaction really require other humans, and a patient, calm, supportive and knowledgeable team member who really does just seem like one of the guys or girls could be an extremely valuable asset in keeping a team together and functional. Regular meatbags might do, of course, but the robotic kind knows more and thinks faster, suffers fewer psychological issues and has much simpler upkeep (no need for fancy food, or anything as luxurious as "a place to sleep", just a generator and a power lead). They're also much more reliable at providing high quality feedback to their supervisors, untainted by opinion, emotion or prejudice. And when the need arises, they'll definitely do what is required of them, no matter what the cost.
You build killer robots so you take fewer human casualties. Everyone cares when people come home in boxes, but no one minds when robots are killed.
Your enemy knows this. They preferentially kill the humans, leaving the 'bots when possible.
Artillery strikes, sniping, air strikes, ambushes - there are any number of cases where the enemy might hold back if they realize that there is an all robot force, or where they might shift fire to concentrate on the humans if they are present.
By making the androids at least good enough to pass as human from afar, you can deny them this ability to target your valuable human soldiers.
Bonus points - you can say that no one trusts the kill-bots completely - the humans are present to be OFFICERS. By preferentially killing the humans the enemy is removing your leadership from the field. You decision making is slowed, mistakes are made because the kill-bots are optimized for tactical efficiency vice strategic thought. Striking at the vulnerable humans is a big problem that you can solve by hiding them among the robots.
Fully human-like androids would have the advantage of being able to pass as civilians or even enemy combatants to bypass enemy lines, could be made to be walking bombs that nobody pays attention to until it's too late, and commit acts of discreet sabotage and intelligence gathering that robotic looking soldiers could not.
Most of the time, these robots have other jobs.
Your combat androids are not woken up just to fight. They are awake all the time. They can fight. But most of the time they are not fighting. They have civilian jobs. They are stationed in the Outer Dark, working with humans on remote asteroids and stations. It is lonely out there for the humans, and there might only be a few real ones. Possibly just one. It is easy to start to go mad if you are a human all alone. By stationing androids alongside your humans out on the frontier you can improve the morale and mental health of the humans who are out there too.
The humans do know these things are really machines. But it is easy to forget that when they look and act like your fellow humans.
