The criminal offense of unlawful assembly generally means the assembly of multiple persons resulting in conduct that (1) is intended to commit a breach of the peace or other unlawful act; (2) creates an immediate danger of damage to property or injury to persons; (3) substantially obstructs law enforcement or other governmental functions or services; (4) is tumultuous or violent and likely to cause public alarm; or (5) 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.

Unlawful assembly laws vary from state to state and some states have related offenses such as rioting, riots and routs, participating in a riot, inciting a riot, failing to disperse, and disturbing the peace. The criminal offense of unlawful assembly may be included in the definition of one or more of these offenses or may be a separate criminal offense. These laws are generally located in a state’s statutes—often in the penal or criminal code.

In Kansas, the criminal offense of unlawful assembly is addressed under Kansas Statutes Annotated (K.S.A.) 21-6203, which defines the crime of 'unlawful assembly.' According to this statute, it is unlawful for three or more persons to assemble with the intent to carry out any unlawful act, or to carry out a lawful act in a manner that is likely to breach the peace. The law also covers situations where such an assembly may cause fear or alarm among the public. Penalties for unlawful assembly in Kansas can include fines, imprisonment, or both, depending on the severity of the offense and the circumstances surrounding it. Additionally, Kansas law also addresses related offenses such as rioting and failure to disperse under K.S.A. 21-6202 and 21-6203, respectively. An attorney can provide more detailed information about these statutes and how they may apply to specific situations.