Lawprof Dave Hoffman has an interesting interview with fantasy writer Patrick Rothfuss on the portrayal of law in the fantasy genre.

Rothfuss makes the interesting point that there is nothing antithetical between having a functioning legal system and a society that believes in and uses magic. After all, ancient and medieval legal systems functioned in a society where most people took the idea of magic seriously and believed in the existence of demons, witches, monsters, and so on. The real reasons why civil law doesn't play a big role in fantasy literature area combination of 1) the relative ignorance of most fantasy writers about law and legal systems, 2) the fact that legal disputes are usually not a good way to advance a fantasy plot (as Rothfuss implicitly points out), and 3) the strong demand of much of the fan base for "action"-oriented plots that feature lots of violence and sorcery. However, as Hoffman and Rothfuss discuss, that may be changing with the rise of more "realistic" fantasy literature in recent years; "realistic" not in the sense that the authors' imaginary worlds conform to the laws of science as we know them, but in the sense that the story is set in a more fully developed and internally consistent society. This has already led to a more realistic and sophisticated treatment of political systems by fantasy writers. The same development might also impact the portrayal of legal systems.