Simple assault may also involve an attempt to cause harm to another person, where that attempt does not succeed. Simple assault is typically classified as a misdemeanor offense, unless the victim is a member of a protected class, such as being a law enforcement officer. Even as a misdemeanor, an assault conviction may still result in incarceration and in a criminal record. Aggravated assault involves more serious actions, such as an assault that is committed with the intent to cause a serious bodily injury, or an assault that is committed with a deadly weapon such as a firearm. Aggravated assault is typically classified as a felony offense.Modern American statutes may define assault as including:

an attempt to cause or purposely, knowingly, or recklessly causing bodily injury to another
negligently causing bodily injury to another with a dangerous weapon (assault with a deadly weapon). causing bodily harm by reckless operation of a motor vehicle (vehicular assault). threatening another in a menacing manner. knowingly causing physical contact with another person knowing the other person will regard the contact as offensive or provocative
causing stupor, unconsciousness or physical injury by intentionally administering a drug or controlled substance without consent
purposely or knowingly causing reasonable apprehension of bodily injury in another
any act which is intended to place another in fear of immediate physical contact which will be painful, injurious, insulting, or offensive, coupled with the apparent ability to execute the act.In some states, consent is a complete defense to assault.
Consent may be a complete or partial defense to assault. In some jurisdictions, most notably England, it is not a defense where the degree of injury is severe, as long as there is no legally recognized good reason for the assault. This can have important consequences when dealing with issues such as consensual sadomasochistic sexual activity, the most notable case being the Operation Spanner case. Legally recognized good reasons for consent include surgery, activities within the rules of a game (mixed martial arts, wrestling, boxing, or contact sports), bodily adornment (R v Wilson [1996] Crim LR 573), or horseplay (R v Jones [1987] Crim LR 123). However, any activity outside the rules of the game is not legally recognized as a defense of consent. In Scottish law, consent is not a defense for assault. Arrest and other official acts
Police officers and court officials have a general power to use force for the purpose of performing an arrest or generally carrying out their official duties. Thus, a court officer taking possession of goods under a court order may use force if reasonably necessary. Punishment
In some jurisdictions such as Singapore, judicial corporal punishment is part of the legal system. The officers who administer the punishment have immunity from prosecution for assault. In the United States, the United Kingdom, Australia and Canada, corporal punishment administered to children by their parent or legal guardian is not legally considered to be assault unless it is deemed to be excessive or unreasonable.