Rule 18.Counsel

Group IV: Parties and their Representatives · Last amended October 1, 2013 · Last verified July 14, 2026

In one sentenceRule 18 requires a new Appearance when counsel changes mid-case, bars an advocate from acting as trial counsel after testifying for the client unless the Rules of Professional Conduct allow it, and forbids an attorney from acting as surety on a bond.

Full Text of Rule 18

Text sizeJump to: (a) (b) (c)

(a) When either party shall change attorneys or non-attorney representatives during the pendency of the action, the new attorney or non-attorney representative shall file an Appearance. See Rule 17.

(b) No attorney or non-attorney representative will be permitted to take part in a jury trial after he or she has testified for his or her client therein unless his or her acting as an advocate would be permitted by Rule 3.7 of the Rules of Professional Conduct.

Amendment History

Adopted May 22, 2013, eff. October 1, 2013.

Plain-English Summary

Rule 18 covers three narrow but practical points about counsel. First, when a party changes lawyers or non-attorney representatives while a case is pending, the new representative must file an Appearance, tying back into the filing requirement in Rule 17.

Second, the rule addresses the advocate-witness problem: a lawyer who has testified for a client in a jury trial generally cannot then also act as that client’s advocate in the same trial, unless the Rules of Professional Conduct permit it. This keeps the roles of witness and advocate separate in front of a jury.

Third, the rule bars an attorney from serving as surety or guarantor on any bond or undertaking in a proceeding, closing off a conflict between a lawyer’s financial stake and the lawyer’s professional duties.

Frequently Asked Questions

What happens when a party changes lawyers during a pending case?

Rule 18(a) requires the new attorney or non-attorney representative to file an Appearance, consistent with Rule 17.

Can a lawyer testify for a client and then argue the case to the jury?

Generally no. Rule 18(b) bars an attorney or non-attorney representative from taking part in a jury trial after testifying for the client in it, unless acting as an advocate would be permitted under Rule 3.7 of the Rules of Professional Conduct.

Can an attorney act as a guarantor on a bond in a case they are handling?

No. Rule 18(c) states that no attorney may be surety or guarantor of any bond or undertaking in any proceeding.

Does Rule 18 apply to non-attorney representatives as well as lawyers?

Yes, at least as to changing representatives. Rule 18(a) requires a new appearance whether the party changes to a new attorney or a new non-attorney representative.

Why does Rule 18 limit a testifying lawyer’s advocacy role?

The rule keeps the roles of witness and advocate separate before a jury, permitting a testifying lawyer to continue as advocate only where Rule 3.7 of the Rules of Professional Conduct allows it.

Source & verification. Rule text, official Comments, and amendment history are reproduced verbatim from the New Hampshire Superior Court Civil Rules, adopted by the New Hampshire Supreme Court. Last verified July 14, 2026. · Official source

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