Battery is generally a harmful or offensive contact with another person, without the person’s consent. Battery may be the basis for a criminal charge or offense. The definition and penalties for battery vary from state to state, and are usually located in a state's penal or criminal code (statutes). In some states the crimes of assault and battery are merged into one criminal offense.

Battery is also recognized in tort law as an intentional tort, and may result in civil liability (money damages) in a lawsuit against a person who commits battery.

In Montana, battery is not specifically defined as a standalone offense in the criminal code. Instead, Montana law typically refers to the offense of 'assault,' which encompasses acts that would be considered battery in other states. Under Montana Code Annotated (MCA) § 45-5-201, a person commits the offense of assault if they purposely or knowingly cause bodily injury to another, negligently cause bodily injury to another with a weapon, or purposely or knowingly make physical contact of an insulting or provoking nature with any individual. The penalties for assault in Montana can range from fines to imprisonment, depending on the severity of the offense and whether it is classified as a misdemeanor or a felony. Additionally, in civil law, a person who commits an act of battery in Montana may be held liable for damages in a personal injury lawsuit. This civil liability requires the victim to prove that the perpetrator intentionally performed a harmful or offensive contact without consent, resulting in injury or damages.