R.I. Gen. Laws § 17-20-7: Duplication of votes — Methods preferred.

(a) In no event shall more than one vote be cast by any individual for any one office or proposition.

(b) In the event that any person votes in person and also attempts to vote by mail ballot or by an official state blank ballot or an official federal absentee ballot, as the case may be, the mail and the official state blank ballot and the official federal absentee ballot, as the case may be, shall be destroyed and not counted.

(c) In the event that any person casts a mail ballot and an official federal absentee ballot and/or official state blank ballot, the mail ballot shall be counted, but the official federal absentee and/or the official state blank ballot shall be destroyed and not counted.