Ad litem (Latin: "for the suit"[1]) is a term used in law to refer to the appointment by a court of one party to act in a lawsuit on behalf of another party such as a child or an incapacitated adult, who is deemed incapable of representing him or herself.
In England and Wales, since the amendment of the Children Act 1989 established the role of children's guardian, the term is now used only in the term "guardian ad litem" in Private Law proceedings under rule 9.5.
The legal system in the Republic of Ireland also uses the term guardian ad litem.
Judges ad hoc are particularly common in international courts, and are fewer in number elsewhere.
The Latin term (ād lītem) translates literally as "for the suit"[2] or "for the proceeding".