Under what circumstances can a lawyer obtain a proprietary interest in a cause of action?

A lawyer can obtain a proprietary interest in a cause of action specifically to acquire a lien for attorney's fees. This exception is rooted in ethical guidelines that allow attorneys to secure payment for their services without violating prohibitions against sharing in the client’s recovery or becoming too financially invested in the outcome of a case.

Establishing a lien for attorney's fees is permissible because it serves the critical function of ensuring that lawyers are compensated for their work while still maintaining the integrity of the attorney-client relationship. This interest does not create such conflicts that other forms of proprietary interests might, as the lien specifically relates to the fees owed for the legal services rendered, rather than the merits or outcomes of the case itself.

The other choices indicate scenarios that could lead to potential ethical breaches. Investing in the subject matter of litigation, pursuing proprietary interests for any deemed beneficial reason, or seeking personal legal gains could compromise the lawyer's duty of loyalty to the client, create conflicts of interest, or give rise to concerns about the lawyer's motivations in representing the client effectively. Thus, the established guidelines restrict the obtaining of interests in a cause of action to certain circumstances, with liens for fees being a clear allowance within the professional conduct framework.