[¶ 1] Frederick Wheeler appeals from the judgment entered in the Superior Court (York County, Crowley, J.) following a jury verdict in favor of Russell B. White. Wheeler contends that the trial court erroneously instructed the jury on the issue of causation. Because we conclude that the jury charge in its entirety did not prejudice Wheeler, we affirm the judgment.
I.
[¶ 2] Wheeler initiated this action against his former attorney, Russell White, alleging negligent representation, breach of contract, and negligent infliction of emotional distress. In February of 1992, Wheeler engaged White to assist him in leasing commercial property located in York. Wheeler testified that he informed White that the property’s owner was experiencing financial difficulties, that Fleet Bank held a mortgage on the property, and that Wheeler wanted to secure a long-term lease. Wheeler and White agreed that White would prepare a lease and would record a memorandum thereof. White advised Wheeler that “[t]he memorandum of lease is a good idea because recording this would give you better protection against a possible foreclosure.” White acknowledged that he did not counsel Wheeler as to the advisability of his obtaining either a subordination agreement or nondisturbance agreement.
*126[¶3] In May of 1994, Wheeler learned from a friend that the leased premises was to be auctioned as a result of a foreclosure. Wheeler then contacted White, who admitted that he had recorded neither the lease nor the memorandum of lease but indicated that he would do so promptly. The property eventually was auctioned, and although Wheeler attempted to purchase it, he could not. In December of 1994, Wheeler surrendered the leased premises.
[¶ 4] At trial, Wheeler testified that if “White had told [him] back in 1992, in February of 1992 that [he] could be evicted by an existing mortgage holder, and that the memorandum of lease would not protect [him],” then he would not have leased the premises. He also testified that if White had indicated that a subordination or a nondisturbance agreement would have provided some protection, then he would have instructed White to negotiate such an agreement with Fleet Bank.
[¶ 5] White conceded that a subordination or nondisturbance agreement can protect a lessee from eviction in the event of a bank foreclosure whereas a memorandum of lease does not protect against foreclosure. White testified, however, that his prior dealings with Fleet Bank had given him the impression that the bank generally does not enter into subordination agreements. He also opined that Wheeler’s circumstances were not likely to facilitate the negotiation of a subordination agreement because “he was already in the property” and because “he wasn’t presenting a large financial benefit to an institution.” He testified that when he met with Wheeler in February of 1992, Wheeler had already moved into the leased premises.
The court instructed the jury, in relevant part, as follows:
in this case Frederick Wheeler, the Plaintiff, has claimed that the Defendant, Russell White, negligently caused his injuries. In order to prevail in this action for legal malpractice, the Plaintiff must prove by a preponderance of the evidence that the Defendant, Russell White committed professional negligence in his representation of the Plaintiff by deviating from the appropriate standard of care as you find it from the testimony of the attorneys in this case_ Two, but for Defendant’s professional negligence the Plaintiff would not have taken the tenancy or would not have lost his tenancy in the property he leased_ And, three, that the Defendant’s negligence was a proximate cause of the total loss or damages claimed by the Plaintiff Frederick Wheeler.
If the Plaintiff, Frederick Wheeler, does not satisfy you by a preponderance of the evidence that the Defendant, Russell White, committed negligent conduct back in 1992, then the ease is over.... If the Plaintiff, Frederick Wheeler, does satisfy you by a preponderance of the evidence that the Defendant was negligent, you must next consider proximate cause. Let me explain that term to you.
Negligence is the proximate cause of damage if it plays a substantial part in causing the damage and the damage is a direct result of the negligence or the damage was a reasonably foreseeable result of the negligence. A loss may have more than one legal or proximate cause. Two or more persons or things may act together independently or together to cause injury or damage. And in such a case each may be a legal cause. If the Plaintiff, Frederick Wheeler, doés not satisfy you by a preponderance of the evidence that Russell White’s negligence was the proximate cause of his damages, the case will be over. If, however, the Plaintiff has satisfied you by a preponderance of the evidence of both negligence and proximate cause against Russell White, then before you consider Frederick Wheeler’s damages you must first consider the defense of contributory negligence that’s been raised by the Defendant Russell White.
The Defendant here, through his attorney, contends that the Plaintiff, Frederick Wheeler, negligently caused his own injuries. This is a defensive claim and the burden of proof on this claim by a preponderance of the evidence is on the Defendant ... if you find in favor of the Defendant, Russell White, on his defensive claim *127of contributory negligence, then you must next apply our law of comparative negligence to apportion the relative fault or responsibility for the damage.
The jury returned a verdict in favor of White, unanimously responding in the negative to the first question on the special verdict form, “[w]as defendant Russell White negligent, and was his negligence a proximate cause of injury and damages to Plaintiff Frederick Wheeler.” This appeal followed.
II.
[¶ 6] “We review jury instructions ‘in their entirety to determine if they are adequate, taking into consideration the total effect created by the instructions and the potential for jury misunderstanding.’ ” Thompson v. Pendleton, 1997 ME 127, ¶ 13, 697 A.2d 56, 59 (quoting Adamatic v. Progressive Baking Co., 667 A.2d 871, 874 (Me. 1995)). An error in a jury instruction does not constitute reversible error unless it results in prejudice. See Adamatic v. Progressive Baking Co., 667 A.2d 871, 874 (Me.1995).
[¶ 7] The burden on the trial court in this ease was to instruct the jury properly with respect to the causation element of a legal malpractice claim. As in all actions in tort, an essential element of the plaintiffs cause of action
is that there be some reasonable connection between the act or omission of the defendant and the damage which the plaintiff has suffered. This connection usually is dealt with by the courts in terms of what is called “proximate cause,” or “legal cause.” There is perhaps nothing in the entire field of law which has called forth more disagreement, or upon which the opinions are in such a welter of confusion.
W. Page Keeton et al„ PROSSER and Keeton on the Law op Torts § 41, at 263 (5th ed. 1984). As noted by Dean Zillman and his colleagues in Maine Tort Law, “[t]he issue of proximate cause has fascinated and baffled generations of lawyers, academics, and jurists.” See Zillman, Simmons & Gregory, Maine Tort Law § 7.12 at 7-29 (3d ed. 1997).
[¶8] We observed in Spickler v. York that “[i]n a malpractice action, as in any other action based on negligence, a negligent act ... is a legal cause of harm to such other person if ‘the actor’s conduct is a substantial factor in bringing about the harm.’ ” 566 A.2d 1385, 1390 (Me.1989) (quoting Wing v. Morse, 300 A.2d 491, 496 (Me.1973)) (emphasis in original). Thus, in a legal malpractice case, once a plaintiff demonstrates that the defendant attorney was negligent, the plaintiff must show that that negligence actually and proximately caused his or her injury. The trial court instructed the jury: “[i]n order to prevail in this action for legal malpractice, the Plaintiff must prove by a preponderance of the evidence that.... Two, but for Defendant’s professional negligence the Plaintiff would not have taken the tenancy or would not have lost the tenancy in the property he leased.” White argues that our case law supports the court’s instruction, citing Sohn v. Bernstein, 279 A.2d 529, 532 (Me.1971), Schneider v. Richardson, 411 A.2d 656, 658 (Me.1979), and McAlister v. Slosberg, 658 A.2d 658, 660 (Me.1995). We note, however, that the cases cited by White do not involve an allegation of contributory negligence on the part of the plaintiff. As Professor Prosser notes:
Restricted to the question of causation alone, and regarded merely as a rule of exclusion, the “but for” rale serves to explain the greater number of cases; but there is one type of situation in which it fails. If two causes concur to bring about an event, and either one of them, operating alone, would have been sufficient to cause the identical result, some other test is needed.
Keeton et al„ supra, at 266.
[¶ 9] The trial court’s use of a “but for” instruction was ill-advised, for this is a case in which two causes may have occurred to bring about an event and either one of them, White’s negligence or Wheeler’s contributory negligence, would have been sufficient to cause the result.
[¶ 10] Professor Prosser suggests the “substantial factor” formulation to be an improvement over the “but for” rale. We agree. In this case, evidence was presented upon which a jury could have found White negligent and Wheeler contributorily negli*128gent. The court correctly instructed the jury that “negligence is the proximate cause of damage if it plays a substantial part in causing the damage and the damage is a direct result of the negligence or the damage was a reasonably foreseeable result of the negligence.” The court went on to instruct the jury on the law of comparative negligence and explained how they should complete the jury verdict form. Wheeler argues that the jury was misled by the court’s unfortunate use of the “but for” instruction. Wheeler asserts that the “but for” instruction implied that for him to recover the jury had to conclude that White’s negligence was the sole cause of his damages. The jury was, however, fully instructed upon the principles of comparative negligence. On the record presented to us, we cannot conclude that the jury was misled. See Stanley v. Sckiavi Mobile Homes, Inc., 462 A.2d 1144, 1149 (Me.1983). Reading the jury instructions in this case in their entirety, we find them to be adequate and, taking into consideration the total effect created by these instructions, we conclude that there was no potential for jury misunderstanding.
The entry is:
Judgment affirmed.