Suppose you are a clerk in a 7-11, or a teller in a bank, or just walking down an alley when a robber appears in front of you, brandishing a knife or gun and demands that you hand over the $$$$.
Now, suppose that you react entirely non-violently - no sudden moves, no violence against the crook, no raising of voices or anything, but just calmly but firmly say “no” - and persist with the calm, polite “no” - how likely is this to result in an anatomically bad outcome for you?
Not “need answer fast” 
If the robber is the type not willing to actually follow through on their threats your odds probably won’t change much, but if you’re dealing with someone willing to use violence then I’d think that type of resistance would be just as likely if not more likely to provoke a beating than violent or aggressive behavior.
In the eyes of an impatient violent person you’re being a smart-ass or disrespecting/challenging them by pulling a bluff when they believe they are in the right and also in a hurry. Stubbornness like that may well provoke the same reaction as a kid who folds their arms and says “NO” to going to bed… only the swat on the butt to get them moving in this situation is a pistol whipping to smarten you up.
I saw a video where 2 women were being robbed in a store but not doing what they were told. They didn’t act aggressively but just wouldn’t cooperate. The guy had a knife and started test-stabbing one of them… which got a reaction more to his liking. Then he really started going after one of them, and when she fell started attacking the other. Put them in their place, even though I don’t think he actually got any money before running off.
A friend of mine was shot and killed by a carjacker for refusing to turn over his keys. Another friend actually had a mugger pull the trigger after he had turned over his wallet - luckily for him the gun jammed and the mugger took off.
Anecdotes are not data, of course. But based on what I’ve seen, if someone points a gun at you, they aren’t bluffing.
That sounds like something that only Christopher Walken could get away with.
Seriously though, that sounds like a really poorly thought out course of action.
You must consider that your armed robber has already made the decision that what you have is worth risking the penalty for being caught taking it from you. They’ve either deemed the risk low enough or the payout great enough to justify the risk. This is bad for you.
They are, in that moment, demanding your compliance and enforcing that demand with threat of serious bodily harm. Non compliance or active resistance would likely be viewed as an invitation to demonstrate their willingness to compel you further. Given time is usually of the essence in these matters, this would require the reassesment of the risk(to include violent escalation) to be done in an emotionally charged atmosphere, on the fly. Consider this person is likely predisposed to violent behavior. This is looking worse for you.
This is very likely to result in an anatomically bad outcome for you.
Now consider your risk. As a clerk or teller we’ll assume they want the esblishments money, not yours personally. You lose nothing if they take what they came for and run. You live, that’s a win.
If they take your car and your Rolex and run. You live, you buy a new over priced watch(becuase hypothetical you can obviously afford that shit), and that’s a win too.
You say no, politely of course, then die in the driver seat of a beat up 1982 Mercury with expired registration(hypothetical you has grossly misplaced priorities) and you get to demonstrate how very principled and committed you are, as a dead man.
It entirely depends on the robber. Here’s another anecdote.
My brother’s friend from the neighborhood was coming back from out of stare with another friend. They were around 20ish. They didn’t have enough money for gas so they decided to rob some gas station. They had a gun with them.
First time ever. They got caught and were sentenced to prison.
I’m pretty sure that they wouldn’t have actually used the gun if the guy refused.
I have absolutely no idea what percent of armed robbers are like that, but it seems pretty damn foolish to roll the dice in that situation.
Side question - can an employer legally compel employees to defend company assets/money with their lives/bodies? i.e. “Bank tellers who comply with robbers will face penalties, up to and including termination?”
But if they could, would they? I’d would bet that if they did they’d be subjecting themselves to the risk of lawsuits from your next of kin that could cost them twice the money any able-bodied robber could physically carry out the door.
I’d imagine any employer that did so would first make their employees sign waivers to the effect of “Yes, I consent to put my body on the line.”
But I may be taking my own thread off topic.
[Moderating]
Unless this sort of resistance is so common that there are statistics on it, I can’t see how there can be a factual answer to this one. Moving to IMHO.
A couple of anecdotes.
Anecdote #1:
I have a cousin who works in a bank as a teller. One day a robber came in and demanded money. She laughed at him and told him no. He ended up leaving in frustration without hurting anyone.
My cousin also got in big trouble from her boss. Bank policy is to give the robbers what they want so that (hopefully) no one gets killed.
Anecdote #2:
Some asshole who just wanted to rob a house so that he could buy some crack ended up stabbing and killing a good friend of mine just because my friend happened to be home at the time. The crackhead did not go into the house with the intention of killing anyone. I have no idea if my friend resisted, or what happened. Some people think that most robbers don’t want to kill and will back down or flee instead of killing. I don’t believe that to be true. Some people just have no regard for life and don’t care if they kill someone.
Anyway, Mr. Crackhead is in jail for the rest of his life, and my friend is dead. The big haul from the robbery? About $150 worth of tools. That’s it.
My personal opinion based on a lot of experience dealing with criminals is that it won’t go well.
Most robbers have a plan in their mind for how they want the robbery to go. If the victims are lucky, that plan does not involve violence.
But if the victims resists, the robber is likely to see this as the victim not doing what he imagines they are supposed to be doing. And he’s likely to get angry at them for not doing what he feels they should be doing, messing up his plan, and making his life difficult. He’s going to figure the victims deserve to get shot for screwing things up.
I remember researching this very question for a similar question a few years ago and I forgot the actual stats but IIRC non-violent and being fully cooperative with a robber outside your home still resulted in actual injury 10% of the cases (actual being anything that required hospitalization) and death in 1% of cases. Nonviolent resistance increased injury but decreased death chances oddly enough, believe it was 30% chance of injury to 0.5% chance of death.
I’ve been a store cashier for five years, and the rule is simple: If someone with a weapon demands your money, you give it to them. Someone else in the store is to immediately open the emergency door, setting off the alarm, which will have the fire department coming down from up and block and storming the place in about 30 seconds.
I think it depends on the perp’s situation. A thug who’s just shaking down targets of opportunity may be rational about risk vs. reward, in which case someone who resists their bluff threat without presenting a threat of their own may come through unscathed. OTOH, AIUI, many drug addicts who are experiencing severe withdrawal symptoms are thinking about little besides doing whatever it takes to score their next hit; if you present any kind of obstacle to their goal, they may just shoot/stab/bludgeon you to death and then take your wallet out of your pocket for you.
There are also thugs with nothing left to lose but their dignity (when you humiliate them by saying no), and impulsive thugs who can’t think farther than two seconds into the future. Defy either of these, and you risk fatal consequences.
How do you reliably tell the difference between any of these types in the heat of the moment? Beats me.
Not worth it to find out.
The incident that put bullet proof shields over the driver’s seats on CTA buses was a bus driver who was confronted by a gun toting thug threatening to shoot, who said to the thug, “I’d like to see you try it.”
The thug shot him in the chest. The driver died later.
I say later because the newspaper had a picture of the bus driver getting off the bus with a bloody shirt.
He looked very surprised. No word on whether he liked what he saw when the thug shot him.