What is the primary exception for a lawyer to acquire an ownership interest in a cause of action?

The primary exception for a lawyer to acquire an ownership interest in a cause of action lies in the context of a contingency fee arrangement in civil cases. Under the Model Rules of Professional Conduct, specifically Rule 1.5, a lawyer may enter into a contingency fee agreement where the lawyer's fee is contingent upon the outcome of the case. This means that the lawyer has a vested interest in the success of the client's case, as their payment will depend on the client prevailing and receiving compensation.

Contingency fee arrangements are permissible because they allow clients who may not have the upfront resources to pursue legal claims to access legal representation. It aligns the interests of the lawyer and the client, as both stand to gain from a favorable outcome. However, this practice is heavily regulated to ensure that it remains fair and transparent, requiring clear communication and consent from the client, typically in writing.

The other options do not align with the established rules regarding lawyers acquiring an interest in causes of action. For instance, ownership interests are not universally allowed in criminal cases, and verbal permission from a client is insufficient to protect the integrity of the client-lawyer relationship. Similarly, while written consent is crucial for many matters in law, it does not inherently grant authority to lawyers to acquire ownership