Rioting or participating in a riot generally means the assembly of multiple persons resulting in conduct that (1) creates an immediate danger of damage to property or injury to persons; (2) substantially obstructs law enforcement or other governmental functions or services; (3) is tumultuous or violent and likely to cause public alarm; or (4) deprives any person of a legal right or disturbs any person in the enjoyment of a legal right by using force or the threat of force.

Rioting laws vary from state to state and some states have related offenses such as inciting a riot, unlawful assembly, failing to disperse, and disturbing the peace. These laws are generally located in a state’s statutes—often in the penal or criminal code.

In Massachusetts, rioting and related offenses are addressed under the General Laws of Massachusetts. Specifically, Chapter 269, Section 1 of the Massachusetts General Laws defines the crime of 'Riot' as when three or more persons, with the common purpose to do an unlawful act, or a lawful act by unlawful means, assemble and act together in a violent and tumultuous manner that causes or creates a clear and present danger of, or results in, damage or injury to property or persons. The law also covers the offense of 'Incitement to Riot,' where an individual is prohibited from inciting or urging others to riot. Additionally, Massachusetts law includes provisions for 'Unlawful Assembly' under Chapter 269, Section 2, which makes it a crime for three or more persons to assemble with the intent to do an unlawful act by force, or to do a lawful act in a violent, tumultuous, or intimidating manner. The law requires that such an assembly must be ordered to disperse by a public official, and failure to do so can lead to charges. 'Disturbing the Peace,' under Chapter 272, Section 53, is another related offense that involves engaging in disorderly conduct that tends to disturb the public tranquility. Penalties for these offenses can include fines, imprisonment, or both, depending on the severity of the actions and the resulting harm or danger caused.