Ohio Rev. Code Ann. § 5321.02 – Retaliatory action by landlord prohibited

(A) Subject to section 5321.03 of the Revised Code, a landlord may not retaliate against a tenant by increasing the tenant's rent, decreasing services that are due to the tenant, or bringing or threatening to bring an action for possession of the tenant's premises because:
1. (1) The tenant has complained to an appropriate governmental agency of a violation of a building, housing, health, or safety code that is applicable to the premises, and the violation materially affects health and safety;
2. (2) The tenant has complained to the landlord of any violation of section 5321.04 of the Revised Code;
3. (3) The tenant joined with other tenants for the purpose of negotiating or dealing collectively with the landlord on any of the terms and conditions of a rental agreement.
(B) If a landlord acts in violation of division (A) of this section the tenant may:
1. (1) Use the retaliatory action of the landlord as a defense to an action by the landlord to recover possession of the premises;
2. (2) Recover possession of the premises; or
3. (3) Terminate the rental agreement. In addition, the tenant may recover from the landlord any actual damages together with reasonable attorneys' fees.
(C) Nothing in division (A) of this section shall prohibit a landlord from increasing the rent to reflect the cost of improvements installed by the landlord in or about the premises or to reflect an increase in other costs of operation of the premises.