Oregon Revised Statutes Probate Law § 112.272

(1) Except as provided in this section, an in terrorem clause in a will is valid and enforceable. If a devisee contests a will that contains an in terrorem clause that applies to the devisee, the court shall enforce the clause against the devisee even though the devisee establishes that there was probable cause for the contest.

(2) The court shall not enforce an in terrorem clause:

(3) The court shall not enforce an in terrorem clause if the contest is brought by a fiduciary acting on behalf of a protected person under the provisions of ORS chapter 125, a guardian ad litem appointed for a minor, or a guardian ad litem appointed for an incapacitated or financially incapable person.

(4) For the purposes of this section, “in terrorem clause” means a provision in a will that reduces or eliminates a devise to a devisee if the devisee contests the will in whole or in part.

(5) This section is not intended as a complete codification of the law governing enforcement of an in terrorem clause. The common law governs enforcement of an in terrorem clause to the extent the common law is not inconsistent with the provisions of this section.