Ohio Rev. Code Ann. § 2953.21
(A)
(1)
(d) At any time in conjunction with the filing of a petition for postconviction relief under division (A) of this section by a person who has been sentenced to death, or with the litigation of a petition so filed, the court, for good cause shown, may authorize the petitioner in seeking the postconviction relief and the prosecuting attorney of the county served by the court in defending the proceeding, to take depositions and to issue subpoenas and subpoenas duces tecum in accordance with divisions (A)(1)(d), (A)(1)(e), and (C) of this section, and to any other form of discovery as in a civil action that the court in its discretion permits. The court may limit the extent of discovery under this division. In addition to discovery that is relevant to the claim and was available under Criminal Rule 16 through conclusion of the original criminal trial, the court, for good cause shown, may authorize the petitioner or prosecuting attorney to take depositions and issue subpoenas and subpoenas duces tecum in either of the following circumstances:
(g) If a petitioner, prosecuting attorney, or person from whom discovery is sought makes a motion for an order under division (A)(1)(f) of this section and the order is denied in whole or in part, the court, on terms and conditions as are just, may order that any party or person provide or permit discovery as described in division (A)(1)(d) of this section. The provisions of Civil Rule 37(A)(4) apply to the award of expenses incurred in relation to the motion, except that in no case shall a court require a petitioner who is indigent to pay expenses under those provisions. Before any person moves for an order under division (A)(1)(f) of this section, that person shall make a reasonable effort to resolve the matter through discussion with the petitioner or prosecuting attorney seeking discovery. A motion for an order under division (A)(1)(f) of this section shall be accompanied by a statement reciting the effort made to resolve the matter in accordance with this paragraph. The orders that may be made under division (A)(1)(f) of this section include, but are not limited to, any of the following:
(G) A petitioner who files a petition under division (A) of this section may amend the petition as follows:
(J)