The law applicable to smart contracts is a neglected topic. At times it is even discarded as irrelevant or unnecessary. In fact, many authors claim that smart contracts especially when stored and executed with the help of blockchain technology make contract law and, in fact, the entire legal system obsolete. “Code is law” is the frequently cited catchphrase. In the following chapter I will challenge this view and argue, first, that smart contracts need contract law just as other, traditional contracts, and, second, that the applicable contract law can—at least in most cases—be determined with the help of the traditional rules of private international law.