Given the circumstances of arbitration as an alternative dispute resolution mechanism, which is, prima facie, based entirely on the autonomy of the parties that intervene, it is crucial to protect the legitimacy of the process and ensure that it is not affected by the lack of prevision in its regulation. In the case of party appointed experts, regulation is inexistent. Being the designation of experts a fundamental right of the parties, a specific regulation is necessary, for its inclusion, or in any case, its exclusion, under no circumstances mean a threat to the rights of the party that appointed them.