Numerous lawprof bloggers, including Steve Bainbridge, Christine Corcos, David Hoffman, and our own Senior Conspirator are commenting on the portrayal of law in fantasy literature - or rather the seeming lack thereof.
I don't agree with those (Hoffman and Bainbridge) who argue that fantasy literature mostly ignores legal issues. Litigation is indeed absent in most fantasy works. But the absence of litigation is not the same thing as the absence of law. To the contrary, many famous fantasy works do use legal disputes as a central theme. The dysfunctional nature of the legal and political system of the Wizarding world is a central theme and plot device in the Harry Potter books - the most popular contemporary fantasy series. The Harry Potter books even include several trials. Rowling's negative portrayal of the wizard legal system is, of course, also a way to criticize some aspects of our own Muggle law.
Disputes over property rights are central to the work of J.R.R. Tolkien, the biggest influence on the modern fantasy genre. Tolkien's The Silmarillion, the back story to the Lord of the Rings centers around a dispute over the ownership of the silmarils - a set of valuable magic jewels. The Lord of the Rings also features a wide range of property disputes, including the competing claims to the ownership of the Ring itself. For my Property class, I once created a handout illustrating the various common law modes of property acquisition using examples from LOTR. We've got acquisition by creation (Sauron's claim to ownership of the Ring), acquisition by conquest (Isildur's claims); acquisition by find (Gollum); acquisition by exchange (Bilbo, winning the ring in a game with Gollum); and acquisition by gift (Frodo). Gollum could also claim ownership by adverse possession were it not for the fact that adverse possession does not apply against personal property. On a more serious level, LOTR also criticizes the expropriation of traditional property rights by modern government, as in the portrayal of the "gatherers and sharers" who confiscate the Hobbits' property in "The Scouring of the Shire."
Most fantasy novels are set in societies too poor to be able to support an extensive formal legal system that relies on complex litigation. Moreover, litigation is unlikely to make fun reading for the target audience. But that doesn't mean that fantasy literature ignores law. It often does address it, but in a different way.