From The Truth about Violence: 3 Principles of Self-Defense by Sam Harris The rest is worth reading. He argues basically avoid conflict and if it starts get the hell away as fast as possible. This is basically good advice outside of turf wars, screaming like a scalded sissy as you run away flinging valuables in every direction is also best practice. In my experience burglars will take their chances with an occupied house even if it is also likely to be armed but its probably safest to assume the worse. Some will kill in the excitement of flight, especially if on their 3rd strike, a few come with that direct intent. Common police advice in the US on detecting an intruder is to forget about that new plasma screen downstairs, grab the firearms, get the family into a secure room and call 911, a tricky maneuver best practiced. I do think it might take quite a lot of mental preparation for 250 pounds of Papa Bear actually to be legging it out the patio doors as the machete gets taken to the twins. However it certainly increases his odds of survival, I may start rehearsing this shortly.