This article examines the evolution of ethical rules for lawyers and judges, and considers the various forums in which these rules have appeared. The article centers upon the use of these rules in the context of a criminal trial of an attorney or judge and discusses the court's preliminary finding of materiality and/or relevance of the ethical rules to the issues of the criminal trial. In those cases in which the courts have found ethical rules admissible as evidence or as a jury instruction, they are admitted as either a "rule of law' or as a "guidance." The distinction between these two roles is studied, as well as the prejudicial effect of admitting the rules. Finally, the article reflects upon the harms which accrue by the admission of these ethical rules, and the remedies available to curtail future application of these ethical rules in criminal trials of judges or attorneys.