Don't give them what they want
Chris Byrne at The Anarchangel - in a simple robbery, the safest bet is to give the perp what he wants. The second it escalates to violence or the threat of violence, however, you're likely dead unless you resist, with as much force as you can muster, until the threat is ended. You should have already known that, but Mr. Byrne says it well. [kimdutoit]
If you're dealing with what cops call an ODC (ordinary decent criminal), then most likely nobody is going to get hurt; but once things tip over that edge, you are effectively a dead man already, unless you act to prevent that from happening.
You should NEVER comply with a rapist, or a criminal who is intent on violence; and ALL rape is violence of the worst sort.
You should NEVER comply with a criminal who is clearly mentally unstable, or grossly impaired mentally by drugs or alcohol.
It should go without saying, that you should NEVER comply with a criminal who has invaded your home, private office, or car; as these are automatically at an escalated level of violence (because they are emotionally violent and risky acts as well as physically).