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 Colorado, burglary is defined under state statutes and is classified into different degrees based on the circumstances of the offense. The basic definition aligns with the general concept of burglary, which involves unlawfully entering or remaining in a building or structure with the intent to commit a crime therein. Colorado recognizes three degrees of burglary. First-degree burglary (CRS 18-4-202) is the most serious and involves burglary of a dwelling coupled with assault or the use of a weapon. Second-degree burglary (CRS 18-4-203) typically involves unlawful entry into a building or structure with intent to commit a crime, but without the aggravating factors of the first degree. Third-degree burglary (CRS 18-4-204) generally relates to breaking into safes, vaults, or other secure repositories to commit theft or another crime. Additionally, Colorado law also includes a charge for possession of burglary tools (CRS 18-4-205), which criminalizes the possession of any tool with intent to use it in a burglary. The specific circumstances of the unlawful entry, such as the type of building and the defendant's actions, will determine the degree of the burglary charge and the potential penalties upon conviction.