Burglary is generally the unlawful entry of a building or structure to commit a felony criminal offense (crime), theft, or assault. The definition of burglary varies from state to state (and in the federal system), and some states have different degrees of severity of the burglary offense—depending on the nature of the unlawful entry (type of building or structure), the intended purpose, and the illegal action taken by the defendant once inside the building or structure. In some states, breaking into an automobile, a coin-operated machine, or an ATM (automated teller machine) with the intent to commit a theft may also constitute the crime of burglary.

In New Hampshire, burglary is defined under RSA 635:1 as entering a building or occupied structure, or separately secured or occupied section thereof, with the purpose to commit a crime therein, unless the premises are at the time open to the public or the actor is licensed or privileged to enter. The state distinguishes between different types of burglary such as 'burglary' and 'armed burglary'. The severity of the charge can be influenced by factors such as whether the building is a dwelling, whether the burglary occurred at night, and whether the perpetrator was armed or if a person was present in the building at the time of the crime. New Hampshire law also considers the intent of the person entering the structure; if the intent is to commit a theft or felony, it constitutes burglary. The penalties for burglary can range from misdemeanors to felonies, with more severe penalties for armed burglary or burglary of a dwelling. It's important to note that New Hampshire's definition of burglary may not include the unlawful entry into vehicles or other non-structured properties unless they meet the criteria of a 'structure' as defined by the law.