The New York-based law firm Pryor Cashman can’t avoid a malpractice lawsuit by relying on language in an assignment-of-rights agreement that the firm itself drafted for the client.

In a four-page decision issued Tuesday, the Appellate Division, First Department, ruled that Pryor Cashman “should be equitably estopped” from arguing that the assignment-of-rights language it drafted for plaintiff Deep Woods Holdings LLC “did not assign tort claims,” including malpractice claims, and therefore Deep Woods has no right to sue the law firm.