The use of force in self-defense is a defense to many criminal charges, from felony to misdemeanor level. But when it comes to self-defense law, courts look to the totality of circumstances. There is no bright-line test. But one important factor is “disparity of force.”
Yes, disparity of force means what it sounds like. It means that lawful use of force in self-defense is reasonably proportionate to the threat of force you face.
Stress of the moment & disparity of force
As a defender from criminal violence, you’ll be aware of the situation and make your best assessment in the moment. As you do, you will consciously or unconsciously note factors that will guide your mental attitude and response actions.
If you do use force in self-defense, you may later need to justify your use of force, legally. A jury, judge, police officer, media, and the community will all consider the factors you face. And you should consider these factors at the moment of threat to your personal safety.
But the people judging you will not experience the stress of being under attack, or the time pressure. They will have the benefit of comfortable, stress-free hindsight, with access to information you did not yet have at the time (including subsequent events).
Legal self-defense, too
Second-guessers: Sometimes it seems that no matter what choice a person makes, someone imagines they could have done better. And whatever evidence a prosecutor chooses to present to a jury, that jury must work to overcome “hindsight bias.”
That gap between the ideal and the real may seem inevitable, but how can we at least reduce it?
Physical self-defense training is vital. And it’s also important to consider these issues deeply. That way, when they come up we’ll be more prepared to make the right choices.
Disparity of force changes everything. What are the factors that help make up the totality of circumstances for lawful use of force in self-defense?
Situational awareness, of disparity of force
The first foundation of personal safety is “situational awareness.” After all, if we misperceive our environment, we could either over-react or under-react. And either could result in disaster.
Attention budget: So we strive for a high level of awareness of our situation at all times. But all humans have a limited ability to pay attention. And when we divide our attention across multiple objects, we degrade our awareness. Focus of attention means less wide situational awareness.
We can enhance safety by heightening our situational awareness, depending upon time, place and immediate circumstances. For example, relaxing within the safety of our home, we may have no problem multitasking. But while driving our car, or walking – we may divide our attention. We might do two things at once. If we divide our attention between tasks by say, focusing attention on our smart phone; we degrade our wider awareness and safety.
The good news? Training helps. Practice helps. But we can also avoid or reduce the impact of dividing our attention.
Stay frosty
Alcohol and other intoxicants also degrade our awareness. When police stop a driver on suspicion of DWI, they will generally ask the driver to perform roadside field exercises. Most of these are “divided attention tests.”
Alcohol can impair a person’s ability to divide her attention and perform two tasks at the same time. We can avoid the alcohol or impairment by alcohol to maintain our ability for situational awareness.
Alert & Oriented (x3): Our Personal Responsibility
When it comes to criminal violence, we need to be aware of other humans. We need to be aware of proximity, threat potential, and potential responses to any threat presented (plan B).
We can adjust to threats before the risk of violence grows. For example if we are situationally aware and spidey-sense a possible threat, we can cross the street or move away.
Sometimes situational awareness will not help us avoid trouble. But if we are suddenly attacked, situational awareness can help us respond in the best possible way under the circumstances. And when it happens, we must weigh disparity of force factors instantly, under stress in the moment.

Disparity of force or threat
The core of self-defense law is the use of reasonable force under the circumstances. That’s why the question of “proportionality” is key.
If you face a threat of attack, or an attack, the law expects you to act reasonably. And it expects you to use force reasonably proportionate to the threat or force used upon you.
Several common factors increase the threat to you. These include the size of the attacker, number of attackers, and weapons.
Size & strength: disparity of force
If you are a 100 pound, 65-year-old woman facing a 200 pound, 20-year-old man threatening rape or robbery; that is a disparity in size and strength. Would that disparity justify your use of greater force, vs. the reverse situation? We know it would.
Relative size and strength is a disparity of force factor.
Single attacker vs. multiple attackers
It is more difficult for one person to defend against multiple attackers than a single assailant. As a result, a person defending against multiple attackers must use more aggressive and more lethal force.
Against a single unarmed attacker, forcing them to initiate not only has a tactical advantage but also a legal one. But against multiple attackers, it may be necessary for the self-defender to strike first, perhaps against the apparent leader.
Multiple attackers are a disparity of force factor.
Sobriety vs. intoxication
Alcohol (and other drugs) is a wild card. And it can cut in multiple directions. We should consider it, since most assaults and crimes against persons involve alcohol.
Assuming a two person conflict, either or both may have been drinking. Generally “voluntary intoxication” is not a defense to criminal liability. But it can have a big effect on both intent and physical ability. And even those can vary with the person’s level of intoxication.
Intoxication could make the aggressor a greater threat than if sober. If so, the use of greater or more lethal force could be justified.
Intoxication is a disparity of force fact.
The use of force continuum
The force continuum is the range of levels of force. Implicit within the term, use of force continuum, is proportionality.
Depending upon the circumstances, calling 911 and the presence of a police officer; or a verbal warning and display of a weapon, might be on the lower end of the force continuum. A threat in self defense is lower on the use of force continuum than the actual use of force.
We calibrate our response to the disparity of force the attacker presents. So our response is dispassionate, and proportionate.
Perspective matters
The community would like us to use the lowest level of force possible to avoid or resolve a physical conflict. Yet we view self-defense from the perspective of the defender, what they knew then, and the pressures of the situation perceived at the time.
In a criminal case, in criminal law, we judge whether an act was criminal from the point-of-view of the defendant.
Even so, the defendant’s acts must have been reasonable under the circumstances at the time. Therefore, we must view all events from the perspective of a reasonable person in the defendant’s shoes. And if you’re a self-defender, you are that potential defendant.
Verbal & nonverbal communication
To the extent possible, communicate verbally and non-verbally with the criminal assailant. Give clear verbal warnings.
Depending upon circumstances, you may be communicating de-escalation or escalation. Communicate whichever is then most likely to stop the threat or the criminal act.
Escalation, where used, should avoid fighting words or provocation. Instead, use verbal commands to stop the attack, disarm, and the like. “Put down the weapon! Step back! I don’t want to hurt you!”
Call 911 first: You may also be communicating so that your intentions are clear to any witnesses or electronic observation. Where possible, call 911 to request police help as well as to create an audio record of what is happening.

Empty-hand defense
It’s good to have options. And it’s nice to have a force-multiplier if attacked. Of course, having a weapon does not mean that it must be used, or revealed.
Empty-hand defense can also vary in level of force. For example, we might disable an unarmed attacker with a snap kick to the knee to break their leg.
So, if we are capable of stopping the attacker effectively with a lower level of force or injury, we will.
We will try to use the lowest level of force to effectively stop the threat from the assailant.
Armed with weapon
What if either you or the criminal attackers have a weapon? A weapon is a big disparity of force factor. And your force-multiplier can be a great equalizer.
Usually a person with a weapon will try to conceal its presence. We use our situational awareness to detect whether they have a weapon. The weapon could be either within reach, on their person, or in their hand.
Since a weapon in hand is the greatest threat, we try to see whether a weapon is in their hand. A clue may be that the person conceals one or both hands behind or otherwise out of sight. If it seems possible, a verbal command may be in order: “Drop the weapon! Now!”
If you have a weapon, depending upon circumstances, you may choose to keep it hidden. Most trainers advocate keeping a weapon out of sight until it is necessary to use it.
Exception to the general rule: Displaying a weapon as part of a warning to avoid injury could be reasonable, self-defense.
The circumstances make all the difference. Be aware, however, that showing a weapon as a threat can lead to a “brandishing” assault charge.
Perceived disparity of force, turns out to be wrong
Legally, afterwards, the issue may arise of whether the defendant reasonably believed the assailant had a weapon. This is a big problem when police don’t find a weapon later. You subjectively perceived a disparity of force. But it later turns out you were wrong.
To reduce this risk, try to be sure the criminal does have a weapon; verbalize the presence of a weapon; and if possible be sure police later are able to locate it. (Point it out.)
Lethality of weapon
When it comes to weapons, some have lesser or greater levels of force – for example pepper spray vs. a handgun. So, the lethality level of the weapon affects disparity of force.
A weapon is a force-multiplier. It can multiply the level of force that you are capable of using in self-defense.
Proximity to the threat is another factor that relates to force-multipliers. A knife can be a better close range weapon than a gun, for example.
It’s nice to have choices, when it comes to lethality of weapons. Police officers generally have more equipment than other folks do. But whether we are at home, in the car, or out and about, most adults have choices available to them. The factors limiting choice may be, on the one hand knowledge and training, and on the other hand, convenience.
Range and distance; proximity
Distance is important when it comes to reasonable fear of imminent great bodily harm or death. Some open-hand fighting styles are long-range or short-range. A kick can reach farther than a punch. Different weapons have different effective ranges. A baton has a shorter range than an arrow.
A closer threat creates a greater disparity of force.
The law of self-defense has no bright-line, just a totality of circumstances test. That test means discretion and judgment.
Life experience, personal or indirect
Discretion is rooted in the experience of the beholder. Rather than personal training, today the average person’s “experience” is indirect. It’s from stories they’ve read, seen or heard. Most often it’s from entertainment media such as songs, books; and especially movies and television.
These mythological “experiences” are problematic since they tend to be wrong more often than not. For example, when someone shoots someone with a gun in the movies, they drop dead immediately. But in real life, that is rare.
So even after shooting a knife-wielding attacker twenty-one feet away; that attacker can still kill the defender with that knife. See “The Tueller Drill.”
“Once engaged, don’t stop until the threat stops. Once the threat stops, disengage.”
After you’ve been attacked, continue the necessary, reasonable use of force in self-defense until the threat is over. The use of force is no longer necessary, after the attacker is disarmed, disabled or otherwise no longer a threat. It stops.
But It may be a challenge to determine when this point has been reached, depending upon the situation.
Leaving the area as soon as it can be safely done, is often a good idea. For example, other attackers could be in the area, unseen. On the other had, getting help for the injured criminal, if possible, is also often a good idea. A 911 call for help could work. Or, if clearly safe to do so, render First Aid.
We do not seek retribution
Once the threat is disabled or stopped, we stop using force.
We do not take it upon ourselves to punish, or teach a lesson to the wrongdoer. Nor do we stoop to revenge. We do not express anger. In fact, anger is the enemy – both in self-defense tactics, as well as legally.
What do you think about disparity of force?
Are there other factors we can weigh when considering whether a person’s use of force was in self-defense?
How does disparity of force influence what is reasonable self-defense?
The Author; resources on disparity of force
Thomas Gallagher is a Minnesota Criminal Lawyer.
His practice includes asserting the defense of self-defense and defense of others, on behalf of clients.

Self-defense and the Other
Escalation, Dominance, Deception in Self-defense
Gun-related pages of interest
Gun Crimes Defense Attorney
Prohibited Person in Possession of a Firearm
What is firearm possession?
Gun With No Serial Number (privately made firearm)
Carrying under the influence