Assault and battery are criminal acts which, when they occur concurrently, are often prosecuted as one offense. Assault is understood essentially as the offering of a threat of violence or some other form of physical offense to another person. Battery is defined as the performance of a physical act causing bodily harm or offensive physical contact to another person.
In the common law system in place for the United States, assault can often be proved to have occurred in cases which satisfy the conditions that a person proposed to cause some form of physical harm to another individual, that this proposal took place in such a context so as to make the threat appear likely, and that the person making this promise of physical harm appeared to possess the ability to make good on it.
Under the same system, battery is found in cases in which unlawful touching was committed against an individual by another person with the intention and effect of causing physical harm or perceived offense.
Because assault may stop short of the threatened harmful and physical action and not involve its fulfillment, it can be said that assault does not necessarily include battery, but that a case of battery implies that assault has already or simultaneously occurred. Because of this fact, it will often be found that legal systems, such as those of American states, conflate the two offenses.
To varying degrees, the finding that assault and battery takes place depends on the determination that it did so without the defendant possessing some form of privilege to commit such acts against the claimed victim. It will vary according to the specific legal culture as to how far it can be reasonably assumed that this principle is at play.
Commonly cited considerations in the American system of law include the issuing of consent to the attacker, such as in the context of a violent sports contest, the need to defend oneself or other people against the violence of others, the performance of official duties related to law-enforcement, a fight which is voluntarily entered into by both participants, and the need to protect one’s own property.
If the performance of these various functions are found to have gone beyond what are deemed “reasonable” limits, as defined by law or interpreted by legal courts, consent may not prevent the act in question from being considered assault and battery.
The prosecution of assault and battery can include both felonies and misdemeanors and can also arise as a subject for tort law. Under United States law, assaults prosecuted individually are generally treated as misdemeanors except in the most severe cases of assault, which are classified as aggravated assault.
Under the same system, the determination of whether a battery constitutes a felony or a misdemeanor depends in part on where it falls in a graded system which serves to establish the severity of the crime, and thus, of the crime. In the United Kingdom, on the other hand, battery is not graded in terms of severity