Imagine you are walking to your car after a late-night movie and a masked man with a knife jumps in front of you and demands money. He creeps closer. You must decide: hand over your wallet, draw your concealed pistol and protect yourself, or run away. Florida has a stand your ground rule. This means any law-abiding person may stand their ground to defend themselves against the masked knifeman.

In Florida, you are justified in using or threatening to use deadly force if you reasonably believe that using or threatening to use such force is necessary to prevent imminent death or great bodily harm to yourself or another, or to prevent the imminent commission of a forcible felony. As long as you are in a place you are legally allowed to be, didn’t provoke the attack, and weren’t engaged in criminal activity, you will have the right to stand your ground.

Thanks to this rule, a prosecutor cannot argue that you should have fallen back before defending yourself. As you might have guessed though, you can lose this vital protection. First, you will not be protected if you do not have a legal right to be at the location where you use deadly force. Imagine you are taking a shortcut through a public park that is closed from dusk til dawn and has “No Trespassing” signs posted. As you walk through the dark park, another trespasser pulls a knife and attempts to rob you. Since you do not have a right to be in the park, the law would require you to attempt to flee if you could do so before using deadly force to defend yourself.

Secondly, you won’t be protected if you use deadly force after provoking someone and starting a fight. Picture a minor fender-bender: You and the other driver stop and get out of your vehicle. You’re so angry with the crash that you challenge the other driver to a fight, knowing that you have your concealed gun with a round in the chamber. When you get nose-to-nose with the other driver, you push him and he pushes you back. You’ve lost your right to stand your ground, because you were the initial aggressor. If it becomes necessary to use deadly force as the fight escalates, you will only have the right to do so after exhausting every reasonable means to escape the danger of death or great bodily harm prior to your use of deadly force.

Thirdly, if you are engaged in criminal activity when you use deadly force, you forfeit your legal protections under the “no duty to retreat” stand your ground rule. Imagine if you go to a bar after a stressful day of work, you forget to remove your every-day carry, and you become intoxicated. The resident tough guy starts to harass you and breaks a beer bottle on the bar, turning it into a deadly weapon. Although you still have a right to defend yourself, if you draw your concealed weapon and fire in response, you may have to explain why you didn’t try to run away first.

It is very important to remember that the stand your ground and castle doctrine laws vary from state to state. Just because you could legally shoot the masked knifeman in our earlier example in Florida, does not mean you can do so in other states.