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Don’t Bring a Gun to a Knife Fight: The 21-Foot Rule [VIDEO]

One man is armed with a knife, the other a gun. Who will win the fight? The answer might surprise you.

Watch the video to see why a gun is sometimes not as effective as a knife.


The 21-foot rule was originally introduced in 1983 by Lt. John Tueller, formerly of the Salt Lake City Police Department.

The rule states that an attacker wielding a bladed weapon (like a knife) could fatally engage an officer armed with holstered handgun from a distance of less than 21 feet due to the concept of a “reactionary gap.” In short, sudden action is generally faster than defensive reaction. The closer an assailant is to his victim, the less time they have to react defensively.

The video illustrates the effective distance of the knifed attacker being cut in half when the officer’s gun is already drawn. The particular officer’s level of training and proficiency with his weapon also impacts the amount of time it takes to get off an accurate shot on an approaching attacker.

Shooters who use their guns as self-defense tools should keep the 21-foot rule in mind. Hope for the best, but prepare for the worst. Planning and practice will increase your chances of surviving if you ever find yourself in the worst case scenario.


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Don’t Bring a Gun to a Knife Fight: The 21-Foot Rule [VIDEO]