Ezel / Ethics Opinions / OSB
OSB April 2026

Can an Oregon lawyer file a complaint against a defendant who has a valid affirmative defense the defendant may not have discovered?

Short answer: Yes, qualified. As long as the claim has a basis in law and fact that is not frivolous under Oregon RPC 3.1, the lawyer may file it; it is up to the defendant or the defendant's counsel to discover and assert any available defense.

Apply this to your situation

This page answers the general question as of 2026. Ezel answers yours: whether it's allowed on your facts, under the current Oregon Rules of Professional Conduct, with citations.

Disclaimer: Advisory only. Not binding precedent.
About this page: The plain-English summary, reader guidance, and Q&A below were written by Ezel based on the official ethics opinion. The original opinion (linked on this page as a PDF) is the authoritative source for any reliance.
View original ethics opinion (PDF)

Plain-English summary

A client asks the lawyer to sue a defendant. The lawyer knows the defendant has a valid affirmative defense to the claim but does not know whether the defendant will discover and assert it. The question is whether the lawyer may file the complaint anyway.

The opinion concludes yes, qualified. It applies Oregon RPC 3.1, which bars a lawyer from knowingly bringing a proceeding or asserting a position without a basis in law and fact that is not frivolous, read together with the candor duties of RPC 3.3(a). The opinion quotes the standard that frivolous means "without factual basis or well-grounded legal argument."

So long as the lawyer has a nonfrivolous basis in law and fact within the meaning of RPC 3.1, the opinion concludes there is no reason the lawyer cannot proceed. The opinion reasons that the lawyer does not represent the defendant, and it is up to the defendant or the defendant's own counsel to look after the defendant's interests and to discover and assert any available defenses.

In practice

The opinion holds that filing an otherwise nonfrivolous claim is permitted even when the lawyer knows of a valid affirmative defense, because RPC 3.1 keys on whether the claim itself has a basis in law and fact, not on whether an opposing defense exists. Per the opinion, the responsibility to raise the defense rests with the defendant and the defendant's counsel.

Common questions

Q: Can a lawyer file a complaint knowing the defendant has a valid affirmative defense?

A: Yes, qualified. The opinion concludes the lawyer may file so long as the claim has a nonfrivolous basis in law and fact under Oregon RPC 3.1.

Q: Does the lawyer have to point out the defendant's defense?

A: No. The opinion concludes it is up to the defendant or the defendant's own counsel to discover and assert any available defenses.

Q: What makes a claim frivolous under this opinion?

A: The opinion quotes the standard that a claim is frivolous when it is "without factual basis or well-grounded legal argument."

Background and rules framework

The opinion interprets Oregon RPC 3.1 (a lawyer shall not knowingly assert a position without a nonfrivolous basis in law and fact), read with RPC 3.3(a) (candor toward the tribunal). These track Model Rules 3.1 and 3.3.

Citations and references

Rules of Professional Conduct:

  • Oregon RPC 3.1 / Model Rule 3.1 (meritorious claims and contentions)
  • Oregon RPC 3.3(a) / Model Rule 3.3 (candor toward the tribunal)

Cases:

  • Cantua v. Creager, 169 Or App 81, 7 P3d 693 (2000)
  • Davis v. Armenakis, 151 Or App 66, 948 P2d 327 (1997)

See also

Source

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