Which rule highlights the importance of clarity in payment arrangements for clients?

Rule 1.5 addresses the importance of clarity in payment arrangements between attorneys and their clients. This rule requires that a lawyer’s fees be reasonable and communicated clearly to the client, ensuring that clients understand what they are being charged for and how payments will be structured. By explicitly requiring this clarity, Rule 1.5 aims to protect clients from unexpected charges and establishes a transparent foundation for the attorney-client relationship.

In contrast, the other rules do not specifically focus on payment arrangements. Rule 1.6 pertains to confidentiality of information, which is crucial for maintaining client trust but does not address fees. Rule 2.1 deals with the lawyer's role in providing candid advice, which is important for overall representation but is unrelated to payment terms. Rule 3.1 focuses on the duty of lawyers to not bring frivolous claims or defenses, emphasizing competence and professional conduct in litigation rather than client billing practices. Therefore, Rule 1.5 is the most relevant in addressing the necessity of clear payment arrangements.