Rule 36.Real Party in Interest
Part III. Parties · Last amended January 1, 2022 · Last verified September 4, 2026
Full Text of Rule 36
Rule History
Added Aug. 30, 2018, effective Jan. 1, 2019. Amended on an emergency basis Aug. 30, 2021, effective Sept. 29, 2021, adopted on a permanent basis effective Jan. 1, 2022.
Plain-English Summary
Rule 36 answers a narrow question: whose name goes on the case.
The general rule
An action must be brought in the name of the real party in interest -- the person whose rights are actually at stake, not a relative, friend or advocate acting in their own name.
When the real party cannot act
Two provisions supply a substitute:
- For an incapacitated person or an adult in need of protection, a guardian or conservator may bring or defend an action or otherwise act on that person's behalf.
- For a minor, a guardian, a conservator, or a best interests attorney may do so.
The best interests attorney is the family law addition. Rule 10 governs that appointment, and Rule 36(c) is what gives the appointee authority to act in the minor's name rather than merely to advise the court.
Who pays
Section (d) lets the court allocate the fees and expenses of a minor's representative between the parties as it deems appropriate. The cost of the child's representation is therefore a matter the court divides, not a charge that falls automatically on whoever asked for the appointment.
Actions for the State
Where a state statute so provides, an action for another's use or benefit must be brought in the name of the State of Arizona. That is the mechanism behind Title IV-D support enforcement, which proceeds in the State's name for the benefit of the parent or child owed support.
Frequently Asked Questions
Who can file a case on behalf of a child?
Rule 36(c) allows a guardian, a conservator, or a best interests attorney to bring or defend an action, or otherwise act, on behalf of a minor.
Who pays for a child's representative?
Rule 36(d) lets the court allocate the fees and expenses of the minor's representative between the parties as the court deems appropriate.
Can a guardian act for an adult who cannot manage their own affairs?
Yes. Rule 36(b) allows a guardian or conservator to bring or defend an action, or otherwise act, on behalf of an incapacitated person or an adult in need of protection.
Why is a child support case sometimes captioned in the State's name?
Rule 36(e) provides that when a state statute so provides, an action for another's use or benefit must be brought in the name of the State of Arizona.
What does real party in interest mean here?
Rule 36(a) requires the action to be brought in the name of the person whose rights are at stake. Sections (b) through (e) then identify who may act when that person cannot.