What is the test for retaining an attorney to draft a will?

The predominant inquiry, Mallen states, is whether the principal purpose of the attorney's retention is to provide legal services for the benefit of the plaintiff. For example, the intention of a testator to benefit legatees, through the retention of an attorney to draft his will, can confer a cause of action in favor of a disappointed legatee against the negligent draftsman. (See, e.g., Lucas v. Hamm (1961) 56 Cal.2d 583, 15 Cal.Rptr. 821, 364 P.2d 685; Biakanja v. Irving (1958) 49 Cal.2d 647, 320 P.2d 16.)