Individual states are responsible for higher education. The legislation of each varies within the guidelines of the Federal Higher Education Framework.
University heads are called rector or president - a recent term that implies more decision-making powers. Both are supported by a head of administration, a chancellor.
They are elected by the university senate or council, which include representatives of professors, students and other academics. Appointments are confirmed by the ministry of the state.
There are at least two or three candidates - usually professors from the university or another institution, although they do not have to be. Some candidates for Fachhochschulen (similar to polytechnics) come from industry.
Campaigns are hard-fought - generally on policy, rather than party political issues.
Terms of office were extended in the 1970s to between four and six years and heads can usually stand once for re-election. The 1998 reform of the framework law on higher education gave universities the right - and in some states the obligation - to set up university councils, which can suggest but not appoint candidates.
Recently universities have been experimenting with new forms of governances.