As a rule, the people decide the composition of the Bundestag every four years. The Basic Law stipulates that its Members be elected in "general, direct, free, equal and secret elections".

"General " means that all German citizens are able to vote once they have reached the age of 18. The elections are "direct" because citizens vote for their representatives directly without the mediation of delegates to an electoral college.

"Free" means that no pressure of any kind may be exerted on voters. "Equal" means that each vote cast carries the same weight with respect to the composition of the Bundestag. "Secret" means that each individual must be able to exercise his or her right to vote in such a way that others cannot ascertain which party he or she has chosen to support.