California Probate Form DE 350 Petition for Appointment of Guardian Ad Litem is important for cases where a minor needs representation. This can be any cases where a minor’s financial interests may be at stake. In those instances Form DE 350 is used to ask the Court to appoint a guardian ad litem to protect the child’s interests. In most counties the guardian ad litem will be a probate attorney taken off a list the Court keeps. The goal is to have an outside, disinterested, party to watch over the youngster’s interests so nobody takes advantage of them on purpose or even unknowingly. It’s a good safeguard the system has in place.