I have litigated a legal malpractice case against a large national law firm for litigating contract and fraud claims poorly. I procured a malpractice expert witness and my claim survived summary judgment, settling mid-trial. I also served as “ethics czar” at a prestigious law firm, researching ethical issues arising in the firm’s practice. I published an academic article on lawyers committing legal malpractice. Any attorney considering filing a breach of contract or a similar claim, especially in a business transaction, absolutely must research which defendant(s) should, can, or must be sued. Such research includes reviewing all documents from the client, checking state websites (like corporate registries maintained by the secretary of state) on all individual and corporate names appearing in those documents, researching all such names in court dockets, and simple internet searching for such claims, etc. To the extent that the proper business entity remains unclear, the plaintiff’s attorney should endeavor to find it out as soon as possible in litigation, whether by contacting defense counsel and by pleading the known identities in the complaint to find out whether the known defendant(s) admit or deny being the relevant entity.