The relevance of previous cases in interpreting law differs according to different legal systems. In general, common law systems work very largely on case law since the "common law" is not written down anywhere and depends on judges "discovering" it. A judge in any particular case will rely heavily on previous judges who have decided upon similar cases or involving similar issues. Although precedence is naturally given to cases from the judge's own country (and from the more superior courts), this approach allows precedents from other countries with a similar legal system to be taken into account also.
Historically, civil law countries did not share this approach. However, the development of international law has provided new interpretative standards in many instances. Thus, for example, Spanish law requires the application of the European Human Rights Convention to be taken into account in interpreting Spain’s own constitution. The case law of regional human rights courts such as the Inter-American and the European cuts across distinctions between common and civil law jurisdictions and is intended to be invoked under either system.
In practice, common law systems have an increasing body of statute law, while civil law systems draw upon the approach in previous cases - including in both systems in relation to the media and elections. The two systems are undoubtedly growing closer together.
