Disqualification of lawyers is regulated by numerous sources, including rules of professional conduct, case law and ethics opinions interpreting those rules, and case law on fair trial, fee forfeiture, and other matters relating to the practice of law.

This course explains the traditional approach requiring disqualification of a law firm and all of its lawyers if a conflict of interest disqualifies any of the firm's lawyers from representing a client on a matter. According to this approach, the conflict of one lawyer is imputed to all lawyers in the firm.