Germany has a civil law system. The laws are codified in written principles as rules of law and are not determined, as in common law, by judges. Accordingly, legislative acts are the primary source of law in Germany, and the court system is usually inquisitorial, unbound by precedent. However, German courts do carefully review previous rulings of other courts, in particular those of the higher instances and, of course, of the Federal Court of Justice. Because of the high volume of patent litigation, Germany now has a well-developed body of precedent that can further lend predictability to the patent litigation process. In patent infringement cases, a jury does not exist. The proceedings must follow the rules provided by the German Code of Civil Procedure.
A defining characteristic of the German patent enforcement system is the split between infringement and invalidity determinations. Infringement and invalidity (nullity) claims are tried in different courts, on different schedules. Infringement cases frequently track ahead of counterpart invalidity proceedings, thus presenting the opportunity to have infringement resolved before invalidity is tried. While the infringement court may suspend its proceedings to allow a corresponding nullity action to resolve validity first, frequently it does not.