Traditionally, big law firms and corporate legal departments have enjoyed a close relationship—one that is based on both trust and regulation. Clients rely on firms to discern legal boundaries and the risks associated with misjudging them; counsel are under a professional obligation to identify and raise potential problems and to handle them competently and thoroughly. Most corporate legal work is outsourced, because it’s not cost-effective to employ enough in-house lawyers to meet companies’ diverse needs. And work is allocated by in-house lawyers, most of whom started their careers and were trained at law firms.

A version of this article appeared in the July–August 2012 issue of Harvard Business Review.