The touchstone of lawyers' professional obligations of devoted client service to their clients is the trilogy of duties: loyalty, confidentiality and care. The most strict and onerous rules in the law of lawyering relate to these duties, and although there is much case law and commentary on the detail of each obligation, their main contours are quite clear.
First, lawyers are supposed to avoid situations involving a conflict of interest between a lawyer's personal interest and their duty to a client; or, a conflict of duties owed to two or more clients. Lawyers are also supposed to refrain from using their relationship with the client as a means of making any personal gain, and they must fully disclose to their client any conflicts of interest or personal gains that do arise. These obligations apply not just to the individual lawyer but to the whole firm: if one lawyer cannot act for a potential client because of a conflict of interest, then usually the whole firm cannot act. These are ‘fiduciary’ obligations set out and enforceable in the law of equity and also reinforced in professional conduct rules and disciplinary decisions. In addition to being sued by their clients for breach of these obligations at general law, lawyers can also be disciplined.
Lawyers also have strict obligations to maintain the confidentiality of information relating to the representation of each client, and generally must not disclose or otherwise use that information for other purposes.