The liberal democratic basic order (German: freiheitliche demokratische Grundordnung (FDGO)) is a fundamental term in German constitutional law. It determines the unalienable, invariable core structure of the German commonwealth. As such, it is the core substance of the German constitution. Building upon more general definitions of liberal democracy, the term has a specific legal meaning in Germany and is part of the German (originally West German) system of a Streitbare Demokratie ("fortified democracy") that bans attempts to dismantle the liberal democratic basic order by what German authorities refer to as "enemies of the Constitution" or "extremists". In practice the concept has been used to target far-left and far-right groups and in the ideological struggle against East German commun