In 1985, the Third Circuit protected as opinion work product a lawyer's "selection and compilation of [intrinsically unprotected] documents . . . in preparation for pretrial discovery." Sporck v. Peil, 759 F.2d 312, 316 (3d Cir. 1985). This common-sense view reflects the work product doctrine's essential purpose — requiring each litigant to do its own work. As long as both sides have access to the same documents, identities of potential witnesses, etc., one side can't discover the other side's selection of what it considers important documents, key witnesses to interview, etc.

In Kalter v. Keyfactor, Inc., the court concluded that the opinion work product doctrine protected the identity "of the specific documents used by Plaintiff's counsel in preparing responses to . . . interrogatories." Case No. 21-cv-1707-L-DDL, 2022 U.S. Dist. LEXIS 208353, at *8-9 (S.D. Cal. Nov. 16, 2022). This essentially common-law expansion of the work product rule triggers a logistical consequence — the withholding litigant's privilege log would not list specific documents, but instead generally describe the asserted scope of protection.

Interestingly, few courts apply this understandable protection to clients' selection of intrinsically unprotected documents about which they seek a lawyer's advice, etc. One would think that a client's selection deserves more protection than her lawyer's selection.