Concealed Carry

The Dangers of the 21-Foot Rule

Police Officer aiming a Glock pistol with a red barn in the background

The word “rule” has been carelessly tossed about by law enforcement and CCW trainers for decades—perhaps it was just misunderstood. In truth, when talking about the 21-foot rule, most are referring to the “Tueller Drill.” Careless lips have led to some dangerous conclusions, especially among the civilian population. It’s a confusion that’s being cynically exploited to get headlines, and it has even reared its ugly head in the courtroom a time or two, but it needs to be addressed for safety.

Police Officer aiming a Glock pistol with a red barn in the background
Teuller’s drill is well suited to law enforcement and civilians, but the 21-Foot Rule is not.

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 the rule or guide to law enforcement. In fact, most of what this article covers will be common knowledge to today’s LEOs. However, I would hope those with experience behind the badge will chime in and challenge or correct the assertions I scribe here by supplementing it with their own experiences. The ultimate purpose is to give some real-world guidance to the nonprofessional concealed gun handlers reading The Shooter’s Log.


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.

Shooter behind cover
Movement and the use of cover is your best defense against any attacker. The is doubly true of an attacker with an edged weapon.
Just as many firearm enthusiasts insist the distinction between a modern sporting rifle and an assault rifle, magazine versus a clip, and a dozen other examples 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 neophyte 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. (This is not word for word, but it covers the general gist.) Second, a helluva lot of law enforcement would be lucky to recognize a threat, unholster their sidearm, and successfully stop the threat from being able to deliver a blow with a knife in less than 1.5 seconds. This was quite a revelation at the time and created much discussion.


Tueller’s lesson should not indicate that anyone, even if they have a knife in hand, is a justified bullet sponge. How many of us carry a pocketknife? Every waitress or busboy in a restaurant would have a target on their chest. Not even in the context of a heated confrontation could you immediately jump to this conclusion. The lesson does not teach that we should shoot a hostile actor with a knife if they are within 21 feet. The lesson merely put a number to the test data and created a mindset for officers to rethink their response and posture to a threat or potentially sudden dynamic attack.

The mindset was fine, but the lessons that followed…not so much. Tueller’s research revealed training deficiencies of the day. As previously stated, it created a lot of discussion, which was good. 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.

Bob Campbell shooting a 1911 pistol from a retention position
Seldom in an emergency situation where you have to draw and fire quickly will you ever see the gun’s sights.
The student had to recognize the threat’s approach, unsnap his holster, and draw his weapon. He failed. In fact, the 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 falling on you. Let’s not forget the audience here. You are likely carrying concealed, not openly in a Sam Brown.

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, situational awareness (which directions could you move off-line, soft and hard cover, etc.), reactionary gaps, and other close-quarters defensive techniques not involving a firearm.

Final Thoughts

The focus of The Shooter’s Log does not include training civilians to be cops or 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. Sadly, I would say while I respect the effort, they have no business standing in front of a student. Too often, I have heard friends (after such training, watching a cop show on TV, or reading something on the Internet) throw out the term “21-Foot Rule”  and improperly state it as a threshold of safe versus justifiable homicide.

I hope, after reading this and the comments from readers with much more knowledge and experience than I have, that you dedicate some of your concealed carry training to going beyond the minimum gun-handling skills and—as important—practicing your communication skills, situational awareness, and good old-fashioned common sense.

What is your impression of the 21-Foot Rule? Have you ever heard of the Tueller Drill? Have you practiced it? Share your answers, opinions, or experiences in the comment section.


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Comments (77)

  1. once married was enough for me. after having a few girls friends for even the same amount of time i just gave up. it would be nice but the problems it brought with it was just to muck. no one would stay if they were anti gun or else they would change their views. anyone that marries someone to change them, well, they are in for trouble.

    the 21 foot rule is telling you to be prepared so you aren’t trying to catch up.if you notice a knife big or small, a stick, bat, club, a liquid bottle with a fuse out of it and a lighter, a pipe with a fuse out of it, or a gun no mater how far away, you should prepare, get your hand on the gun, maybe draw it or not. if the perp is focused on you it should be drawn. if he is yelling and starts toward you, or be taking to you and starts toward you, or just starts toward you get the gun out before he does or at least have your hand on it so the draw will be quicker. you should get off his line perpendicular, or close to it, the hypotenuses of a triangle he will be taking will always be a longer distance, you can even go back the other dirtection and gain more feet.. once he has made you involve producing the gun might just end it and even if it doesn’t you will be able to shoot him quicker.the 21 foot rule is just one that tells you start your draw if you can before he starts to run. why, because you know how bad things can go down quickly. be a step a head. be aware of your surroundings, it tells you you need to be aware quicker and move of the x and keep move off the x it makes his distance further . it also means we all should be practicing shoot on the move. even if he has a gun you should be moving and if you can shoot while moving and he can’t shoot a moving target, you just might win.of course if you show the gun early it might stop the whole problem. i know the 2 times i pulled a gun stopped the incident right off. one was a guy throwing rocks at me, the other were 4 guys with chain, bats, knife and one i could not see both hands and on i could no see what was in his hand. they were coming at me and my friend. i pulled a little 380 fyi and you have never seen 4 people run as fast back to their car. i pointed the gun at the guy i could not see what was in his hand, and after they got back in the car i pointed the gun at the driver thinking he might come forward with the car. instead the car got out of there quickly. i hope i never have to shoot anyone but i will if the circumstances require it.BE AWARE AND IF THINGS LOOK DANGEROUS GET CLOSER TO DRAWING YOUR GUN OR DRAWING IT. IF NEED BE KEEP A LOW PROFILE OF IT. the guy throwing the rocks i had my glock 40 holding it under my arm pit and it was not noticed until i drew it, it was easy the butt was right there. so there are was you can keep it hidden even if you draw at the right time, even covering it with the other arm like your hands are aware and start you defense as early as you can, move off the X and keep moving off the X. i am going to practice firing while i am moving a lot more i think.

    1. ART, I see from your comment that you have learned the proper mindset and are prepared to defend yourself IF NEEDED. Good for you that you have done this. Many years back in my life, I had to face a gun and talked my way out of that one – would do it again if I can but am ready to defend myself if needed.

    2. i have not had to talk my way out of someone with a gun, it is good you could the best fight is the one you are not in.i live in one of those places everyone tells you to stay out is kind of hard to do when you live there.i opened a small shop 30 years ago and the last 2 it has lost money i doubt i will open up next year. over the period of those 30 years i have been threatened with death by large gangs. big national gangs. i have learned to live in the state of orange.the latest is a big coke ring. that gang has threatened me twice now with death and just a few weeks ago i was suckered punch after he told me he was going to slit my throat. a wild hook to the back of my head.i guess he thought he was going to knock me out, but it didn’t. i guess i got a little lax after he kept faking the hook.he then backed up out of reach and felt proud of what he had done. he misjudged me, he was not out of my legs reach, so i kicked him in the balls. he then started claiming i assaulted him. i have a camera system but when he hit me it was out of any of the cameras. i did not know it at the time so i called the police. it did show him as the aggressor though. went to court and had to leave early and do not know what happened yet. he did move off the street. at 70 i am not moving and my knees, well, i am not going to run.i have had stage 3 cancer andmy aortic valve replaced with a pigs. i certainly try and avoid fights if i can but it seems sometimes it is unavoidable. i have a medium size mutt now after my 2 rotties were poisoned. the police won’t help me with these large quantity coke dealers and what i tell the police gets back to the street, so i am not very well likesince over the years i have been threatened over 1/2 dozen tines with death from different national gangs it has become natural to pay close attention to my surroundings. they might be qble to kill me, but they can’t scare me.

      just have bad luck i guess. i rented my parents house out for the first time. they were renters from hell. they destroyed the place. every day off for over 1 and 1/2 years i have been working on it. my sister said i should check it for meth and i did. it turned up positive for it had to do most of the work my self and it certainly has destroyed my finances. it is getting closer to being done but still needs a lot of work. i called the law 2 times and got no response, they did not seem to care they were producing meth there and probably where they moved to. i am getting so tired of the police not doing anything. of course i keep writing 2 jurisdictions chiefs because they would not do anything. i guess i have pissed them off is harder then it ever has been but i keep plugging away.
      this will sound crazy but i believe all drugs should be legal just as prohibition does not ever work neither does the war on drugs. even if they do legalize all the drugs we have made sure we will be dealing through perpetuity with the cartels just as we did with the mafia. crazy, we can’t even learn from history. all this work cleaning up the drugs has not been good for my health i am sure of that. sorry for the rant i just get so pissed over the thing and lack of response from 2 different jurisdictions. my problem though i found out is they combined the narcotics would be nice if they did their job. you would think they would want to find the snitch in the midst.

  2. Condolences on your loss.

    My brother was strange in some ways. Anti-war, yet taught martial arts. He also owned a .45 1911 which he took to the range regularly. H said it helped with his hand eye coordination… and relieved stress. Then he remarried and his wife made him get rid of it. While I’m between spouses, both my priors were pro-gun. The second one said when someone gets divorced there should be a crime amnesty period and whichever one was left standing got everything. LOL

  3. a stick is a stick….

    Because commoners were not permitted to have weapons, or ever touch one, martial arts took everyday tools, the rake, hoe, scythe, and so on and turned them into weapons, along with the weapons the parts of the body became, fingers, knife, axe, club, etc. Anything can be a weapon. We were taught next to nothing in martial arts in the military. I am very thankful we had a ROK Major as an instructor in Vietnam who taught the history and the spiritual sides of martial arts along with the moves.

    On a side note, my kid brother was anti-war but was flown to Japan each year for additional training by his dojo. He was in training to become a Master, and taught at the UofCalif. Unfortunately, cancer brought him down too soon.

    1. DAVE W. May I express sorrow for the loss of your younger brother. I lost my youngest brother in February of this year. On the information you expressed in your comment on “A stick is a stick” is very true for many countries and cultures in history. The origin of many weapons were common farming tools or household items that were pressed into service when needed by commoners to defend themselves. Those weapons became systems of defense over a period of time and are now incorporated into Martial Arts Styles and taught to students. There is always a need however for a student to learn all the basic techniques for hands, feet and body, etc before learning weapons as if the weapon is removed the person is defenseless without the basics to fall back on. Thank you for your comment and information.

  4. Maybe we need a conceal permit Rule–also you add feet or second depend on your age or Disability, Think about It.

    In driving School you have the 2 second rule –Then you add road condition etc–raining add 2 more second–Bad brakes add 1 more second–some jerk is on your Bumper add 2 more second–Get It -???

  5. I am reading the comments above and can see that few of you have ever seen the video Surviving edged weapons or any video along that line. Let me offer insight please.

    I am fourtunate enough to have been a student and instructor of FMA (Filipino Martial Arts) for these last 20 years. In FMA we practice with edged and impact weapons almost primarily; the Filipino Culture being a Bladed Society. I have been lucky enough to be a student of a gentleman named Leo T. Gaje. Leo is a Grandmaster (we say Grand Tuhon) of an art called Pekiti Tirsia Kali or PTK for short. PTK has been called the world’s deadliest martial art; indeed FMA in general certainly is. Leo starred in this film and several others just like it over the years. Produced primarily for Law Enforcement Officers it was not designed to demonstrate how slow you can be when drawing a weapon, but rather how FAST one can be when crossing a seemingly large distance. It was meant to show how not only can a man with motivation or training move in such a way as to eliminate distance as a deciding factor but also to demonstrate that not everyone an LEO encounters cares whether or not he/she lives or dies. The second factor of course being the scariest, especially in today’s society of enhanced threats.

    The lessons taken away from the 21 foot rule is that static positioning when drawing a weapon can be fatal for the LEO and an LEO should be prepared to use other defensive tactics including employment of an impact weapon such as a baton or knife or chair in addition to primary service weapons. Also learning to utilise even a small amount of mano a mano can and will save your life.

    I encourage everyone reading this to seek out PTK or FMA instructors and learn one or two good techniques to fall back on, it may save your life. Tell them Guro Michael sent you..

    1. Michael Paliotta, You are absolutely correct in your knowledge that because a person can move much faster then expected, anybody that is not practiced in MOVING OFF LINE or USING ANYTHING TO DEFEND ONE’S SELF means that person is very venerable to attack. Like you I have studied Martial Arts for over 40 years, learning Korean Hapkido from the Koreans in Korea and one thing that was taught more than any other was to MOVE WHEN ATTACKED, secondly was USE ANYTHING AS A WEAPON from the simple to the specialized Martial Arts weapons used in Hapkido. Since then I have also learned many more weapons and techniques of their use, however the basic techniques learned in Korea do not change much no matter the weapon (Example: a stick is a stick doesn’t matter how short or long it may be if you know how to use it, it becomes a weapon.). Many persons do not take the time to even learn how to use one weapon let alone several different types of weapons to save their lives and to me just like you they are not preparing themselves to defend their lives from attack. Thanking you for your dedication to Martial Arts and you words of WISDOM TO OTHERS.

  6. This has been an insightful discussion. I doubt anyone that has been a Concealed Carrier for any length of time takes issue with the term ‘rule’. We all know it is a basic guide for minimum distance to reveal and/or present. It is that 1.5 seconds for someone who is 100% ready to go, but none of us are (be honest), so we know that is bare minimum. I believe the problem lies with non-shooters perception of the term ‘rule’. Just as explaining why I would want to reload for my hunting rifle or for my handgun for practice; they cannot fathom why someone would need 21 feet or more as a defensive zone.

    We are told we will be judged by a jury of our peers, if that were true, there would be only CCW holders on the jury. But, we will at best have 2 or 3, probably none. Now our Lawyer needs to convince the rest of them the distance between ourselves and the attacker was indeed reasonable even though the prosecutor or the deceased family’s Law Dog said the ‘rule’ was 21 feet and you drew at 28.

    We are each different. You are probably faster than I am. I have had shoulder reconstruction, then later shattered the top of arm. Sorry, If you attack me with a ball bat or knife; I will try to de-escalate things, escape or evade first, but if you charge or crowd me I will not wait until you are 21 feet away before I draw.

  7. I think everyone is making too much of the term “rule”. The first definition (below) is “a prescribed guide for conduct or action”. A “guide” does not equate with a mandatory procedure. In the words of ‘Slick Willie Clinton, it depends on what your definition of is is.’ It is also ” a usually valid generalization” or “a standard of judgment”.

    In my career I have experienced a lot of training and a lot of rules which were subject to existing conditions. This “rule” is only a guide for training purposes used in a classroom environment for demonstration purposes. People are always mixing terms, like when they use the term automatic for a semi-automatic, or call a revolver a pistol. Things I learned which were called “rules” were often not what I considered so. In the field, I used common sense. I didn’t run through a mental list of “rules” in order to decide what action to take.

    Definition of rule
    a a prescribed guide for conduct or action
    b the laws or regulations prescribed by the founder of a religious order for observance by its members
    c an accepted procedure, custom, or habit
    d (1)
    a usually written order or direction made by a court regulating court practice or the action of parties
    (2) a legal precept or doctrine
    e a regulation or bylaw governing procedure or controlling conduct
    a (1) a usually valid generalization
    (2) a generally prevailing quality, state, or mode
    b a standard of judgment
    c a regulating principle
    d a determinate method for performing a mathematical operation and obtaining a certain result
    a the exercise of authority or control :
    b a period during which a specified ruler or government exercises control
    a a strip of material marked off in units used especially for measuring
    ruler 3, tape measure
    b a metal strip with a type-high face that prints a linear design; also
    a linear design produced by or as if by such a strip

    as a rule

    for the most part

    1. We had the benefit of a couple lessons re the”rubber knife at 21 feet” in a TN Tactical Handgun Class some yrs ago.. IMHO only 2 out of 12 students got off even one shot b4 being “stabbed’..I was not one of them.
      What it taught me was ‘……”situational awareness is very important” and I put that in the top 3 things I consider in self-defense:
      1. have a loaded gun
      2. have the WILL to shoot
      3. situatinal awareness

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