The article summarizes the works of foreign scholars on the analysis of the institutional rules of the electoral system, which are considered as a key tool to influence the essential elements of modern political systems. The author dwells on the analysis of factors that stimulate or reduce political competition in the electoral system. In particular, in this paper, such factors as rules of access to the vote, the right to nominate candidates, dependence on public funding of political parties, the influence of the number of seats allocated within the constituency of the nature of imbalances, the system of distribution of seats within parties, internal party selection of candidates, the votes in the conversion system mandates. The Appendix contains a table, which in visual form summarizes information about how the analyzed factors can exert influence on the level of political competition in general, as well as on the party political system, the electoral behavior of voters and the risks of illegal practices in particular