In California probate matters (involving estates, trusts, conservatorships, or guardianships), “abuse of discretion” refers to a failure by either a fiduciary (like an executor, administrator, trustee, conservator) or the Probate Court judge to exercise their legally granted decision-making power (discretion) in a way that is reasonable, impartial, fair, and in accordance with applicable law, fiduciary duties, and the purposes of the governing instrument (like a will or trust). Beneficiaries or other interested parties can petition the Probate Court to review the fiduciary’s actions. If the court finds an abuse of discretion, it can overturn the decision, compel the fiduciary to act differently, instruct the fiduciary, impose personal liability (surcharge) for any resulting damages, or even remove the fiduciary. The term also describes the standard used when an appellate court reviews a decision made by a Probate Court judge on matters where the judge had discretionary power (e.g., setting fees, approving settlements, appointing a fiduciary).