Do you legally have to run away before you defend yourself? So, the answer depends on what state you're standing in and could decide whether or not you go to prison. We're talking about the stand your ground laws. Not every state is a stand your ground state. In Tennessee, you don't have to flee or retreat before you defend yourself with force. There are states where there is a duty to retreat. But, if somebody breaks into your home and intends to do you harm, you shouldn't have to run in your bathroom and hide. The law pretty much presumes that you're entitled to use force in that situation. This doesn't really mean that you can shoot and then ask questions later. What it means is you have to have reasonable fear for your life or serious bodily injury or before you can use force.