Electoral systems do not simply reflect voter preferences, social cleavages, or the political party configuration of a given society. All electoral systems shape and reshape these features. The choice of one electoral system or another involves a decision about what goals decision-makers wish to foster. The present article enumerates six possible goals of electoral systems and then explains how various systems foster or derogate from these goals. In all cases of electoral-system choice, there are tradeoffs. A system may fulfill one objective but make it difficult to attain another. Clarity of objective and attention to the details of system choice are, therefore, necessary.