This book demonstrates under what circumstances it can be sensible for German voters to vote strategically and why. Through formal theoretical analyses, it identifies the conditions under which it is beneficial to vote strategically with either the first or second vote. The book also illustrates how strategic voting in the past has led to the emergence of overhang mandates and why incentives for strategic voting will not disappear, even if we abolish the first vote or eliminate the 5 percent threshold. It thus contributes to a better understanding of the German electoral system and an informed discussion about the consequences of electoral law changes.