The article portrays the ballot paper as a constitutional instrument of electoral democracy. The authors argue that the result of an election often depends on the form, the content, and the method of filling out the ballot. It is shown that a ballot is an election instrument of standard form, by means of which a voter votes for candidates and/or lists of candidates, and which later allows to establish the election results. It is concluded that the definition and classification of ballot types has not only theoretical but also practical value. In particular, this issue is of great practical significance in four cases: 1) simultaneous elections of differing types (sometimes including a simultaneous vote at a referendum); election of candidates for elective offices under different types of electoral systems or different types of territorial constituencies; 3) the vote count and establishing the outcome of the election; 4) prosecuting criminals for the illegal use of ballots.