This article presents experiments that analyze the strategic behavior of voters under three voting systems: plurality rule, approval voting, and the Borda count. Applying a level-k reasoning model approach, strategic behavior is found to be significantly different under each treatment (voting system). Plurality rule leads voters to play in the most sophisticated (i.e. best response), but not necessarily insincere, manner. Thus, this voting system displays at the same time the highest incidence of best responses and of sincere votes. The opposite holds for the Borda count games, where voters depart from their sincere strategy the most, without playing the best response strategy. Approval voting shows intermediate levels of sophistication and sincere behavior.