The crime of assault varies from state to state (and under federal law), but is generally defined as intentionally putting another person in reasonable apprehension or fear of an imminent (immediate) harmful or offensive contact. The crime of assault may be committed even if there is no physical contact, as the criminal physical contact constitutes the separate crime of battery.

The crime of assault with a deadly weapon (also known as aggravated assault) occurs when someone uses a deadly weapon (gun, knife, club, tire iron, brass knuckles, etc.) during an assault.

In Pennsylvania, assault is categorized into two main types: simple assault and aggravated assault. Simple assault is generally defined as attempting to cause or intentionally, knowingly, or recklessly causing bodily injury to another; negligently causing bodily injury to another with a deadly weapon; or attempting by physical menace to put another in fear of imminent serious bodily injury. Simple assault is typically a misdemeanor. Aggravated assault, which includes assault with a deadly weapon, is a more serious offense and is considered a felony. It involves causing or attempting to cause serious bodily injury to another, or causing injury with indifference to the value of human life. Aggravated assault also includes assaulting certain protected classes of people, such as law enforcement officers or teachers, with a lesser degree of injury. The use of a deadly weapon during an assault significantly increases the gravity of the charge and the potential penalties upon conviction.