Don’t Mislead Mediation Participants: What ABA Formal Opinion 518 Teaches

By Robert E. L. Wright,
Mediator & Arbitrator

The Peace Talks, PLC

Introduction: Why Opinion 518 Matters Now

Mediators routinely operate at the intersection of law, psychology, and negotiation. In court-connected mediation—particularly when one or more parties are unrepresented—the mediator’s words often carry heightened authority. Participants listen closely, sometimes treating mediator statements as guidance rather than facilitation.

ABA Formal Opinion 518, issued in October 2025, addresses this reality head-on. The Opinion addresses a lawyer-mediator’s ethical duties as a third-party neutral, with particular emphasis on communications which may mislead unrepresented parties. Its most significant contribution is not simply that mediators must avoid dishonesty, but why neutrality fundamentally changes what mediators may ethically say.

The Opinion addresses three interrelated duties:
(1) clearly explaining the mediator’s role to pro se parties;
(2) maintaining that neutral role throughout the mediation; and
(3) rejecting “puffing” or exaggerated statements that would be permissible for advocates but are unethical for mediators.

I. Explaining the Mediator’s Role to Parties (Model Rule 2.4)

Model Rule 2.4 governs lawyers serving as third-party neutrals. Unlike most Model Rules, which presuppose representation of clients, Rule 2.4 recognizes that mediators occupy a non-representational role and they assist parties who are not clients in reaching resolution.

Rule 2.4(b) imposes two affirmative duties on lawyer-mediators. First, they must inform unrepresented parties that the mediator does not represent them. Second, when a mediator knows or reasonably should know that a party does not understand the mediator’s role, the mediator must explain the difference between serving as a neutral and serving as a lawyer-advocate.

Formal Opinion 518 emphasizes that this obligation is particularly important when parties are unsophisticated or new to mediation. For such participants, simply stating “I don’t represent either of you” may be insufficient. In such instances, the mediator should take care to explain what neutrality means in practice, including that:

no attorney-client relationship exists;
there is no attorney-client relationship between the mediator and the parties;
no attorney-client privilege exists;
only the mediation confidentiality rules apply;
the mediator does not protect any party’s legal or personal interests; and
the mediator cannot provide legal advice.

The Opinion further advises that unless parties are experienced consumers of mediation services, it is prudent for mediators to pause and ensure that participants understand these distinctions and have an opportunity to ask questions.

II. Maintaining Neutrality After It Is Explained

Explaining neutrality is only the beginning. Once a mediator clarifies their role, they must conduct the mediation consistently with that explanation.

Formal Opinion 518 cautions that mediators should be vigilant not even appear to drift—through words or conduct—into the role of advocate or advisor. Statements suggesting the mediator is acting to protect a party’s “best interests,” or that a particular outcome is advisable, risk creating confusion about the mediator’s function.

The Opinion also addresses confidentiality, noting that while mediation communications may be protected under applicable mediation rules or statutes, that protection does not arise from an attorney-client relationship. Mediators should avoid language implying otherwise.

Importantly, mediators may provide general legal information or discuss how courts typically resolve certain issues. They may even offer opinions about the known universe of ways a tribunal might view a claim. What they must avoid is communicating in a way which suggests they are advancing a party’s interests or providing legal advice tailored to the party’s situation.

This distinction becomes critical in the Opinion’s most nuanced discussion: puffing.

III. Why “Puffing” Is Different for Mediators

Formal Opinion 518 devotes substantial attention to a question which has long divided mediators: whether the exaggeration by attorneys tolerated in negotiation is permissible in mediation.

When lawyers represent clients, they operate under Model Rule 4.1, which prohibits false statements of material fact or law but permits certain non-material misstatements—commonly referred to as negotiation “puffing.” Statements about their client’s settlement intentions, bargaining positions, or case valuation are often understood as strategic rather than factual.

Mediators, however, are not advocates. They do not represent clients in mediation. Accordingly, Rule 4.1 does not apply to them. Instead, lawyer-mediators are governed by Model Rule 8.4(c), which broadly prohibits conduct involving dishonesty, fraud, deceit, or misrepresentation. The key question addressed by the Opinion is how that rule applies in the mediation context.

IV. The Reliance Principle: Why Words Matter More When Spoken by an Attorney-Mediator

The ABA’s answer turns on reasonable reliance.

Parties expect opposing counsel to exaggerate, and discount it accordingly. They do not expect exaggeration from a mediator who has expressly disclaimed advocacy and explained their neutral role. As a result, statements which would be dismissed as “puffery” when made by an advocate may be taken as factual and authoritative when made by a mediator.

The Opinion explains that this reliance changes the ethical analysis. A mediator’s exaggeration, bluff, or fabricated constraint is more likely to mislead precisely because of the mediator’s neutrality. What would be immaterial in negotiation may become materially misleading in mediation. That abstract distinction becomes clearest when applied to an everyday mediation moment.

V. A Familiar End-of-the-Day Mediation Moment

The ethical implications of Formal Opinion 518 come into sharp focus in a scenario familiar to many mediators.

It is late in the day. The parties have been negotiating for hours. Fatigue has set in. Emotions have worn thin. The mediator has shuttled back and forth repeatedly and has a clear sense of where the parties are—and where they are not.

In caucus, one party finally asks the question mediators hear all the time:

“Be straight with me—is this really the best they’re going to do?”

The mediator may believe the answer is probably yes. The mediator may also believe that pushing the party to accept the offer would end the dispute and avoid costly litigation. The temptation, at that moment, is to respond with a statement which narrows perceived options:

“I don’t think they’re going to move any further.”

Formal Opinion 518 explains why that response is ethically dangerous.

Once a mediator has explained their neutral role — particularly to an unrepresented party — the mediator’s words are not heard as advocacy or strategy. They are heard as authoritative assessment.

The inquiring party will not discount the statement as negotiation posture. Instead, the party is likely relying on it as a factual constraint conveyed by a neutral professional.

If the mediator does not actually know that no further movement is possible — or if the mediator suspects that movement may still occur under different conditions — the statement risks becoming a misrepresentation, even if spoken with good intentions.

The ethical issue is not whether the mediator meant to deceive. It is whether the mediator’s role caused the party to reasonably rely on a statement which overstated certainty. Formal Opinion 518 makes clear that mediators may not create false finality, even implicitly, in order to induce settlement.

VI. What the Opinion Prohibits (Revisited in Practice)

Viewed through this lens, the Opinion’s prohibitions are best understood not as abstract rules, but as guardrails against undue influence.

Formal Opinion 518 makes clear that mediators may not:

State or imply that a proposed settlement is in a party’s “best interest.”
Say “this is the best offer you will get” if that is not known to be true.
Represent that a party is finished negotiating when the mediator knows or suspects otherwise.
Exaggerate or distort the strength or weakness of a party’s case as the mediator’s own assessment.

What the mediator may not do is convert uncertainty into certainty by borrowing the authority of neutrality.

VII. What Mediators May Still Do

However, the Opinion does not relegate mediators to a purely passive role. Mediators may:

Accurately relay party statements, even if exaggerated, so long as the mediator clearly identifies the source and does not endorse the statement.
Engage in reality testing through questions rather than declarative assertions.
Discuss litigation risks and general legal principles.
Help parties evaluate options without misrepresenting constraints or outcomes.

The difference lies in whether the mediator is facilitating analysis or asserting truth.

In the late-day caucus scenario above, the mediator may accurately convey information — for example, “They’ve told me this is as far as they’re willing to go today” — so long as the mediator clearly identifies the source and does not endorse the statement.

Or, the mediator might simply state, “I don’t know, but would you like to review your options before you respond?”

What the mediator may not do is convert uncertainty into certainty, which would impermissibly convert mediator credibility into leverage.

VIII. Why This Matters Most With Pro Se Parties

Formal Opinion 518 repeatedly highlights unrepresented parties because they are more likely to defer to mediator authority and to misunderstand mediator comments as legal advice or protective guidance.

For pro se participants, a mediator’s statement about settlement options may carry more weight than anything said by opposing counsel. When participation in mediation is court-ordered that deference is often magnified. Parties may feel they are being guided by the judicial system itself.

This is precisely why the ABA insists mediators avoid even well-intentioned exaggeration. The risk is not merely ethical exposure for the mediator, but erosion of the public’s confidence in mediation as a fair and voluntary process which encourages self-determination. Strict adherence to truthfulness protects not only the parties, but the legitimacy of court-connected ADR programs.

Conclusion: Neutrality as Ethical Authority

Formal Opinion 518 does not weaken mediation. It clarifies its ethical foundation. By requiring mediators to explain their role clearly, maintain neutrality consistently, and reject puffing, discounting or exaggerating, the ABA reinforces a central truth: a mediator’s effectiveness depends on trust.

Neutrality creates reliance. Reliance demands truthfulness. And truthfulness, far from impeding resolution, is what makes durable, voluntary settlements possible — especially when the pressure to settle is greatest.