Oregon Revised Statutes Property Rights and Transactions § 90.390

(1) A landlord may not discriminate against a tenant in violation of local, state or federal law, including ORS 659A.145 and 659A.421.

(2) If the tenant can prove that the landlord violated subsection (1) of this section, the tenant has a defense in any discriminatory action brought by the landlord against the tenant for possession, unless the tenant is in default in rent.

(3) A tenant may prove a landlord's discrimination in violation of ORS 659A.145 or 659A.421 by demonstrating that a facially neutral housing policy has a disparate adverse impact, as described in ORS 659A.425, on members of a protected class.