Man crits intruder with fatal bow-and-arrow shot. No charges filed.

Duty to retreat outside of your home basically means that if you have the ability to safely retreat, you have an obligation to do so.

Example 1: If someone is calling you a motherfornicater and swinging his penis around in the general direction of your girlfriend, you don't go up to him and punch him in the face. You call the cops and safely remove yourself from a potentially violent situation.

Example 2: If someone is threatening you with a knife and you reasonably surmise that you will may not be able to run to a position of safety before he overtakes you, you are perfectly within your rights to smash him in the face with the thrift store flower planter you just happen to have in your hands. Should he fall to the ground incapacitated, however, you do not have the right to brain him with the said planter.