Self-defense, self-defence (see spelling differences
American and British English spelling differences
One of the ways in which American English and British English differ is in spelling.-Historical origins:In the early 18th century, English spelling was not standardized. Differences became noticeable after the publishing of influential dictionaries...

) or private defense is a countermeasure
A countermeasure is a measure or action taken to counter or offset another one. As a general concept it implies precision, and is any technological or tactical solution or system designed to prevent an undesirable outcome in the process...

 that involves defending oneself, one's property
Property is any physical or intangible entity that is owned by a person or jointly by a group of people or a legal entity like a corporation...

 or the well-being of another from physical harm
HARM or H.A.R.M. may refer to:* AGM-88 HARM, a high-speed anti-radiation missile* Historic Aircraft Restoration Museum, a museum in Creve Coeur, Missouri, United States...

. The use of the right of self-defense as a legal justification for the use
Use may refer to:* Use , an obligation on a person to whom property has been conveyed* Use–mention distinction, the distinction between using a word and mentioning it...

 of force
In physics, a force is any influence that causes an object to undergo a change in speed, a change in direction, or a change in shape. In other words, a force is that which can cause an object with mass to change its velocity , i.e., to accelerate, or which can cause a flexible object to deform...

 in times of danger is available in many jurisdiction
Jurisdiction is the practical authority granted to a formally constituted legal body or to a political leader to deal with and make pronouncements on legal matters and, by implication, to administer justice within a defined area of responsibility...

s, but the interpretation varies widely. To be acquitted of any kind of physical harm-related crime (such as assault
In law, assault is a crime causing a victim to fear violence. The term is often confused with battery, which involves physical contact. The specific meaning of assault varies between countries, but can refer to an act that causes another to apprehend immediate and personal violence, or in the more...

 and battery
Battery (crime)
Battery is a criminal offense involving unlawful physical contact, distinct from assault which is the fear of such contact.In the United States, criminal battery, or simply battery, is the use of force against another, resulting in harmful or offensive contact...

 and homicide
Homicide refers to the act of a human killing another human. Murder, for example, is a type of homicide. It can also describe a person who has committed such an act, though this use is rare in modern English...

) using the self-defense justification, one must prove legal provocation
Provocation (legal)
In criminal law, provocation is a possible defense by excuse or exculpation alleging a sudden or temporary loss of control as a response to another's provocative conduct sufficient to justify an acquittal, a mitigated sentence or a conviction for a lesser charge...

, meaning that one must prove that he was in a position in which not using self-defense would most likely lead to death or serious injuries.