A note on the legal aspect that has been brought up... you may be required by your state laws to escape, "if possible" rather than defending yourself at all. If an intruder comes through the front door and you don't go out the back door, you can be held criminally accountable for any injuries or death to the intruder.
I personally believe that the progression of reaction should be
3. Defense (only if necessary.)
Out of respect for all of you that wish to ban firearms...I promise to not use mine in your defense