Rule of the Road No. 4: A trial lawyer must tell the client the truth.
This rule should go without saying, but, regrettably, it must be said again and again. In my experience, few actions by lawyers infuriate clients more than the sense that their lawyer has not told the truth or told them only half-truths. Sometimes lawyers are reluctant to give clients bad news. Sometimes lawyers don’t want to admit their mistakes. (A wise lawyer once said, “Crow is best eaten while young.”)
Telling the client the truth is not only a moral imperative, it is part of effective communication with the client. See Rule of the Road No. 3 above. A client cannot make an informed decision if the lawyer does not tell the client the truth. See Model Rule 1.0(e) Rules of Professional Conduct (defining “informed consent”).