R.I. Gen. Laws § 34-20-10: Unlawful termination of tenancy in general.

When proceedings commenced under this chapter are to regain possession of the premises following the alleged termination of a tenancy, if the defendant alleges in his or her answer and if it appears by a preponderance of the evidence that any of the following situations exist, judgment shall be entered for the defendant:

(1) That the alleged termination was intended as a penalty for the defendant’s justified attempt to secure or enforce rights under a lease or contract, or under the laws of the state or its governmental subdivisions, or of the United States.

(2) That the alleged termination was intended as a penalty for the defendant’s justified complaint to a governmental authority with a report of plaintiff’s violation of any health or safety code or ordinance.

(3) That the alleged termination was intended as a penalty for any other justified lawful act of the defendant.

(4) That the alleged termination was a tenancy in housing operated by a city, town, municipal housing authority, or other unit of a local government, and was terminated without cause.