Libertarianism upholds individual liberty as of primary political importance. The concern for liberty leads to support for highly limited government, and sometimes even anarchism. Sometimes people come under the mistaken impression that libertarians have such a myopic concern for individual liberty that they must oppose social rules and social order. While that is too extreme, libertarianism does seem to have significant tensions with social rules, and the role of social rules within libertarianism is complex and contentious. This work aims to bring out some of this complexity and to clarify the important place of social rules in libertarian thought.