The Dangers of the '21-Foot Rule'

When gun owners and shooters talk about the 21-foot rule, most are actually referring to the “Tueller Drill,” which was not a rule at all and which now confuses a lot of well-intentioned gun owners. What is the so-called “21-foot rule?” Where did it come from? What does it mean for the civilian gun owner? These questions and more need to be addressed for the safety of concealed carriers everywhere, so here goes:

Tueller’s Drill was set up to train  law enforcement.

What Is the 21-Foot Rule?

My first introduction to this topic came about 25 years ago while attending the sheriff’s academy. I remember the class and, more important, the video, “Surviving Edged Weapons.” The video and instructional seminars were based on research by Salt Lake City trainer Dennis Tueller. The “21-Foot Rule” was a measure of distance that related to the time it would take an officer to recognize a threat, draw a sidearm, and fire two rounds center mass against an attacker charging with a knife or other stabbing weapon.

To be clear, this article is not intended to be a guide to law enforcement training. The ultimate purpose is to give some real-world guidance to the nonprofessional concealed gun handlers.

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The first issue I have with the 21-Foot Rule is the belief that it is somehow rooted in police doctrine or a legal standard. Removing the number “21” and the word “rule” would go a long way toward dispelling the myth. Tueller’s research did not culminate in a rule; you are not suddenly safer at 22 feet than you were at 20. It is important to distinguish that Tueller developed a drill, not a standard.

Just as many firearm enthusiasts insist on the distinction between a “modern sporting rifle” and an “assault rifle,” “magazine” versus a “clip,” and a dozen other examples of firearms terminology we could come up with off the top of our heads, I believe we need to properly identify our subject as the “Tueller Drill” and not the “21-Foot Rule.” This is not only factually true, it goes a long way toward setting the correct mindset of the civilian gun handler.


There were two main conclusions that can be contributed to Tueller’s research.

First, an attacker with a knife could cover 21 feet in about 1.5 seconds.

Second, a heckuva lot of law enforcement officers would be lucky to recognize a threat, unholster their sidearms, and successfully stop threats from being able to deliver blows with a knife in less than 1.5 seconds. This was quite a revelation at the time, and it changed the mindset of a lot of officers.

The mindset was fine, but the lessons that followed… not so much. Tueller’s research revealed training deficiencies of the day. Where it went wrong, in my opinion, was when they started teaching the number over the mindset. I recall this being demonstrated on the range at the academy. A large, intimidating deputy with a rubber knife rushed a student from 21 feet. The deputy did not run, just marched at a quick pace wielding the knife over his head and screaming obscenities.

The student had to recognize the threat’s approach, unsnap his holster, and draw his weapon. He failed. In fact, truth be told, we all failed. Some may have cleared leather and pulled the trigger, but the threat was so close he still would have struck a blow with the knife.

The 21-Foot Lesson was—graphically—received. Unfortunately, at the time, we learned the number more than the correct lesson.

In time, however, we learned to get off the “X” instead of being a static target. Instead of backing up in a straight line, we were taught to react by moving “off-line.” (Attackers in these scenarios may be so enraged they continue on the beeline path instead of tracking you.)

More important, we were taught to read body language, engage situational awareness (which directions could you move off-line, soft and hard cover, etc.), take advantage of reactionary gaps, and use other close-quarters defensive techniques not involving a firearm.

Final Thoughts

Civilian self-defense training should not focus on teaching civilians to be cops or overemphasize instruction in matters of law enforcement. However, I see far too many videos of self-professed firearm trainers, tactical weapons specialists, home defense “experts,” and even a few prior LEOs who teach like they did to officers or cadets at the academy or in the military and not to civilians. Too often, I have heard friends throw out the term “21-Foot Rule” and improperly state it as a threshold of a safe working distance from an attacker.

I hope after reading this that you dedicate some of your concealed-carry training to going beyond the minimum gun-handling skills and—as important—practice your communication skills, turn on your situational awareness, and use good old-fashioned common sense. —By Dave Dolbee, contributor for The Shooter’s Log at Used with permission.

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Comment section

8 comments on “The Dangers of the '21-Foot Rule'

  1. Thanks for the article. So many times, instructors teach the test. Most anyone can practice enough to pass the test if… they know whats on the test. I’ve had instances in my own training that new students won’t pull the trigger until they hear the word ‘fire’. I hope that I can use some of this article in future class scenerios (sp) to emphasize situational awareness.

  2. Did not know this rule and in a real situation I could see where this may or may not work as far as drawing the firearm after making the decision to pull it.

  3. They taught me to “get away and stay away”,until I could safely draw my weapon and use force to gain compliance,with the rule being minimum force necessary to protect myself

  4. They being the usaf s p academy

  5. Had this happen to me. While answering a call for a possible domestic situation while employed as a hospital police officer in Worcester, MA. A man came at me with a machete in the hall way of a home. I drew and commanded him to drop the weapon several times. (The hallway was about 15 feet long.) After repeated commands I was squeezing the trigger when the assailant stopped just 7 feet from me. No shots were fired, he dropped the machete, and was taken into custody. He still walks freely today but with a different attitude about life. It just doesn’t work this way all the time. He is one lucky man.

  6. This was very a great article, everyone reacts differently in a pressured situation. Twenty-one feet to one person may be a longer distance to another. It depends on your individual training and readiness. Practice being comfortable with your preferred firearm, practice, practice then practice some more.

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