In [[votingelectoral system]]s, '''tactical voting''' (or '''strategic voting''') occurs when a voter misrepresents his or her ''sincere preferences'' in order to gain a more favorable outcome. Any minimally useful voting system has some form of tactical voting, as shown by the [[Gibbard-Satterthwaite theorem]]. However, the type of tactical voting and the extent to which it affects the timbre of the campaign and the results of the election vary dramatically from one voting system to another.