A jury has convicted defendant of the repeated sexual molestation of his young daughter during the five-year period between 1985 and 1990. Some of the evidence admitted at trial related to acts of sexual molestation that he had allegedly committed on an older sister of the victim. Those offenses were claimed to have occurred years before the offenses charged in the indictment.
The trial court instructed the jury that the evidence should not be considered as demonstrating that defendant had a disposition to commit the offenses charged, but failed,' more specifically, to explain to the jury the relevance of that evidence to material issues that were genuinely in dispute and, thus, to constrict the jury’s consideration of that evidence to such issues as were genuinely in dispute.
The jury convicted defendant of aggravated sexual assault, sexual assault, endangering the welfare of his child, and terroristic threats. After merging the sexual assault conviction into the aggravated sexual assault conviction, the court sentenced defendant to an aggregate term of 15 years imprisonment.
In an unreported opinion, the Appellate Division reversed the convictions. The Appellate Division found that the older sister’s testimony was inadmissible because it constituted other-crime evidence that was not relevant to prove intent or to disprove possible defenses of accident or mistake (the purposes for which the trial court had admitted the evidence), and was more prejudicial than probative.
We granted the State’s petition for certification. 157 N.J. 645, 725 A.2d 1126 (1999).
*255I
Because the victim and her older sister have the same first initial, we shall refer to them by pseudonyms. We shall also refer to their mother by a pseudonym. The victim, Laura, was born in 1979. She lived in Monmouth County with her mother, Nancy, her older sister, Linda, two younger brothers, and her father, defendant G.V. In 1985, when Laura was six-years-old, her father began to molest her, frequently touching her intimate parts or having her touch his. When Laura was eight-years-old, defendant began having sexual intercourse with her. On some occasions, defendant forced Laura to engage in sexual activities with her younger brother. Defendant committed these acts at night while Laura’s mother was at work.
A family friend described an occasion when visiting defendant’s home. She was seated directly across from the couch where defendant and Laura were sitting. She saw Laura begin to rub defendant’s shoulders. Defendant brought Laura on his lap and started “stroking” the outside of her thigh. The woman thought that was done in a “sexual way” but dismissed the thought. She and her husband never mentioned the incident'to anyone.
Laura believed that what she and her father were doing was a secret. She never told anyone about it because she was afraid. Defendant had threatened her that if she told anyone, she, her family, and her pets would be killed. The conduct ended in 1990 when Laura was ten-years-old.
About 1989, the family structure changed. Linda (the older sister) married and Laura’s mother and father separated. In January of 1992, defendant was visiting at the family home when Linda and her husband, Walter, were present. There was an altercation between defendant and Walter because defendant brought his girlfriend to the house. Defendant threatened to kill Walter. Nancy called the police and later obtained a temporary restraining order against defendant. Two days later, Nancy agreed to vacate the restraining order because she thought that they could reconcile.
*256After Nancy vacated the restraining order, Laura experienced deep depression. Relatives found Laura in the kitchen staring into space, unable to speak, with her body clenched. She was hospitalized for her disorder. While attending a group session at the hospital, Laura confided in another girl that she had been sexually assaulted by her father. The girl advised Laura to report the matter to one of the attendant doctors. Laura told a nurse. Hospital staff informed the Division of Youth and Family Services and Laura’s mother about the sexual assaults. Laura had not been able to tell her mother because she was embarrassed and ashamed. When Nancy told her other daughter, Linda, about the sexual assaults on Laura, she asked Linda whether their father had ever sexually molested her. Linda revealed for the first time that she too had been sexually assaulted by her father.
Linda said that defendant had sexually abused her from the age of four to eight. When Linda was six-years-old, defendant began having sexual intercourse with her. The assaults occurred at night while Nancy was at work. A complaint was filed charging defendant with the sexual abuse of Laura. (Defendant was not charged with the attacks on Linda because the statute of limitations had expired.) At trial, defendant denied the charges, testified, and presented character witnesses. He asserted that the charges had been fabricated. He contended that the family was angry because he had left Nancy for another woman.
II
Linda’s testimony that her father had sexually assaulted her is referred to as other-crime evidence. The principles that govern the admission of other-crime evidence were recently restated in State v. Marrero, 148 N.J. 469, 691 A.2d 293 (1997). At the time of Marrero’s trial, the admissibility of other-crime evidence was controlled by Evidence Rule 55. Currently, the admissibility of other-crime evidence is governed by N.J.R.E. 404(b), which states:
Other crimes, wrongs, or acts. Evidence of other crimes, wrongs, or acts is not admissible to prove the disposition of a person in order to show that he acted in *257conformity therewith. Such evidence may be admitted for other purposes, such as proof of motive, opportunity, intent, preparation, plan, knowledge, identity or absence of mistake or accident when such matters are relevant to a material issue in dispute.
For convenience, we will conform the references in Marrero to the new rule.
Evidence Rule [404(b) ] makes dear that other-crime evidence is only admissible if relevant to prove some other fact genuinely in issue. State v. Oliver, 133 N.J. 141, 151, 627 A.2d 144 (1993); State v. Stevens, 115 N.J. 289, 558 A.2d 833 (1989). Where the other-crime evidence tends to make the existence of a material fact reasonably likely, it is admissible subject to the “probativeness/prejudice” balancing under Evidence Rule 4, now N.J.R.E. 403.
In addition to being relevant to an issue genuinely in dispute, the other-crime evidence must “be necessary for [the disputed issue’s] proof.” Stevens, supra, 115 N.J. at 301, 558 A.2d 833. Because of its damaging nature, in determining the probative worth of other-crime evidence, “a court should consider ... whether its proffered use in the case can adequately be served by other evidence.” Id. at 303, 558 A.2d 833; see also Oliver, supra, 133 N.J. at 151, 627 A.2d 144 (stating that “[a]n important factor in weighing the probative value of other-crime evidence is whether other, less-inflammatory evidence can prove the same fact in issue”).
Once it is determined that the other-crime evidence is material to a fact genuinely in issue and that the other-crime evidence is necessary, “the probative value of the proffered evidence [must] be carefully balanced against the danger that it will create undue prejudice against the defendant.” Stevens, supra, 115 N.J. at 302, 558 A.2d 833. Where the probative value is outweighed by prejudice to the defendant, then it is inadmissible. Evid, R. 4 (currently N.J.R.E. 403). Consequently, the primary focus of Evidence Rule [404(b) ], when examined in conjunction with Evidence Rule [403], is to view it as a rule of exclusion rather than a rule of inclusion. State v. Cofield, 127 N.J. 328, 337-38, 605 A.2d 230 (1992).
After many years of decisional law determining when other-crime evidence is admissible, a four-part test has been distilled. That test is designed “to avoid the over-use of extrinsic evidence of other crimes of wrongs.” Id. at 338, 605 A.2d 230. That rule is as follows:
1. The evidence of the other crime must be admissible as relevant to a material issue;
2. It must be similar in kind and reasonably dose in time to the offense charged;
3. The evidence of the other crime must be clear and convincing; and
4. The probative value of the evidence must not be outweighed by its apparent prejudice.
[Ibid, (quoting Abraham P. Ordover, Balancing the Presumptions of Guilt and Innocence: Rules W(b), 608(b) and 609(a), 38 Ermory L.J. 135, 160 (1989)).]
*258When other-crime evidence is admitted, “the court must instruct the jury on the limited use of the evidence.” Cofield, supra, 127 N.J. at 340-41, 605 A.2d 230; see also Stevens, supra, 115 N.J. at 304, 558 A.2d 833. Because of the inherently prejudicial nature of other-crime evidence, the court’s instruction “‘should be formulated carefully to explain precisely the permitted and prohibited purposes of the evidence, with sufficient reference to the factual context of the case to enable the jury to comprehend and appreciate the fine distinction to which it is required to adhere.’ ” Cofield, supra, 127 N.J. at 341, 605 A.2d 230 (quoting Stevens, supra, 115 N.J. at 304, 558 A.2d 833).
[State v. Marrero, supra 148 N.J. at 482-83, 495, 691 A.2d 293.]
From Marrero we distill the principles that are crucial to the decision in this case:
• The other-crime evidence must be relevant to an issue “genuinely in dispute.”
• The other-crime evidence must be “necessary for [the disputed issue’s] proof.”
• The court must “explain precisely” to the jury the permitted and prohibited uses of the evidence.
Because those controlling principles were not followed by the trial court, the Appellate Division was constrained to reverse the conviction. Our opinion will review that judgment and seek to correct the implication in the Appellate Division opinion that the other-crime evidence in this case might be inadmissible for any purpose.
Ill
Relying on State v. Cusick, 219 N.J.Super. 452, 530 A.2d 806 (App.Div.), certif. den., 109 N.J. 54, 532 A.2d 1118 (1987), the trial court admitted the evidence of prior sexual abuse. In Cusick, the defendant was charged with sexually assaulting two victims. Cusick argued that he had intended only to swing and cradle one of the victims and that any sexual contact was inadvertent. The Cusick court admitted other-crime evidence to rebut the defendant’s claim of mistake and to establish the defendant’s intent. The Cusick court gave a limiting instruction directing the jury to consider the evidence “as it may bear on the issue of whether the alleged touching of [the victims] was accidental or it was a mistake. Likewise, it might also bear on the defendant’s motive *259for allegedly touching the victims here. This is to obtain some sort of sexual gratification, or on the issue, of his intention to touch the children, victims here.” Id. at 466, 530 A.2d 806.
The trial court reasoned that Cusick’s principles would apply to this case. In its unreported opinion, the Appellate Division explained how in this case neither mistake nor intent to obtain sexual gratification was genuinely in dispute. The Appellate Division explained:
[T]he trial court adopted the prosecutor’s view that earlier attacks on [Linda, the older sister] were relevant to intent in two respects. As summarized in [the State’s] brief: the judge “reasoned that the prior sexual attacks were material because a possible defense by defendant of accident or mistake could be raised by defendant, claiming that he was merely being affectionate towards his daughter and showing her fatherly love. The judge also noted that the State was required to prove that defendant committed the acts for the purpose of sexual arousal or gratification. He thus found that the prior sexual assaults would bear on this issue as it showed defendant committed the sexual assaults on both victims when they were around the same age, between four and eight years old.”
The supposed “possible defense” was never raised by the defendant. Moreover, to do so in the context of this case would have been absurd. If we were dealing with an isolated incident, or even a few separate occasions, of allegedly improper touching, the “possible defense” might have been an issue. But this case involves an horrendous course of patent sexual depravity which continued for years. No reasonable defense, under these circumstances, would rely on the theory that these atrocious acts were simply misinterpreted expressions of fatherly affection.
Nor can it be fairly said that if the defendant committed the acts in question, there was a fnaterial factual dispute with regard to whether he was seeking sexual gratification. As stated in State v. Stevens, 115 N.J. 289, 301, 558 A.2d 833 (1989), a “necessary corollary to the principle that other-crime evidence can be admitted to prove any fact in issue ... is the requirement that the “issue” be genuine, and that the other-crime evidence be necessary for its proof.” Neither of these requirements were satisfied here.
As the prosecutor’s summation plainly demonstrates, the evidence of defendant’s sexual depravity with his first daughter was offered for no reason other than to demonstrate that defendant was predisposed to engaging in sexual conduct with his daughters in their prepubescent years. The evidence was not admissible under N.J.R.E. 404(b), supra. Therefore, the convictions must be set aside and the matter remanded for a new trial.
As the Appellate Division noted, the analytical errors were compounded by the prosecutor’s misuse of the testimony. During summation, the prosecutor made no attempt to suggest to the jury that the other-crime evidence' should be considered only as bear*260ing on defendant’s intent to obtain gratification or to rebut a defense of mistaken physical contact. Instead, the prosecutor described the other-crime events in broad terms that, in essence, urged the jury to use defendant’s character and past conduct as a basis for inferring that Laura’s testimony was true.
The Appellate Division opinion contains longer excerpts of the prosecutor’s summation. The following example will suffice to make the point:
[Laura] said the defendant would say it was our secret, don’t tell anybody. And then as [Linda] got older, sexual intercourse began. Similar fact pattern with
[Laura]. It is just the way Jie operates. It is not two girls getting together. That’s what he was interested in doing, having sex with younger girls, pre-teen age girls.
[Emphasis added.]
If that is not an allusion to propensity, then we do not know what would be.
Our dissenting members suggest that the defenses of accident or mistake or absence of intent to seek sexual gratification were genuinely disputed at least in respect of the charges of criminal sexual contact (that is, sexual contact without penetration as in the “leg-rubbing” incident). If that were the case, then the trial court would have to have had “explain[ed] precisely” to the jury that limited purpose. It did not do so. Moreover, we doubt that the trial court would have found that so limited a purpose would pass the “probativeness/prejudice” test required by Marrero, supra, 148 N.J. at 482, 691 A.2d 293.
Because of the hardship that will be imposed by a retrial of this case, we must consider whether the error may be viewed as harmless. Our courts have on occasion found that inadequate (but not incorrect) limiting instructions were not so prejudicial to a defendant’s fair-trial rights as to require the reversal of a conviction. State v. G.S., 145 N.J. 460, 476, 678 A.2d 1092 (1996); State v. Stevens, supra, 115 N.J. at 309, 558 A.2d 833; State v. Cusick, supra, 219 N.J.Super. at 467, 530 A.2d 806. Our dissenting members suggest that because the other-crime evidence might have been admissible for purposes other than to establish the *261main charge of aggravated sexual assault by penetration, we may view the case as though it were like G.S., Stevens, or Cusick. It is simply not possible to do so. In each of those cases the other-crime evidence was relevant to an issue genuinely disputed in the trial of the charge that led to conviction. In G.S., supra, the evidence of prior sexual abuse of children in Monmouth County was relevant to establish that the sexual contacts in Sussex County, for which he was convicted, were not “inadvertent, accidental or unplanned.” 145 N.J. at 469, 678 A.2d 1092. In Stevens, supra, the prior encounters by a law enforcement officer with women exhibited a purpose to seek sexual gratification, not to fight crime. 115 N.J. at 308, 558 A.2d 833. In Cusick, supra, the prior sexual misconduct tended to prove that the subject conduct was not an accident or mistake. 219 N.J.Super. at 465, 530 A.2d 806. As the Appellate Division noted, the genuinely disputed issues in this ease were not that the intercourse with a child was the result of a mistake because inadvertent or accidental, or evidenced an absence of intent to seek sexual gratification. Intellectual honesty compels the conclusion that there is no genuine dispute that one who has sexual intercourse with an eight-year-old daughter has made a “mistake” or is not seeking sexual gratification. The analysis in G.S., Stevens and Cusick simply does not apply when the evidence is admitted for the wrong purpose. Neither absence of intent or accident or inadvertence or motive were genuinely at issue as to the main crime of sexual assault involving penetration.
Because defendant objected to admission of the evidence, the error in admitting the other-crime evidence cannot be viewed under the less demanding plain error standard of Rule 2:10-2. Nor can the error be salvaged under the harmless error doctrine. If the evidence could not have come in on the main charge, as it did, the error cannot be viewed as harmless. Nothing could be more prejudicial than the erroneous admission of such testimony.
The [harmless error] rule is essential “to conserve judicial resources,” but it must be applied with caution so as to assure “the vitality of the rules and procedures designed to assure a fair trial.”
*262There is enormous potential for prejudice in the improper admission of a defendant’s prior convictions. Commentators have suggested that such error should be considered harmful per se. See The Riddle of Harmless Error, where Chief Justice Traynor wrote:
The erroneous admission of evidence of other crimes also carries such a high risk of prejudice as ordinarily to call for reversal.
[State v. Atkins, 151 N.J.Super. 555, 570, 377 A.2d 718 (App.Div.1977), rev’d, primarily on issue of intoxication charge and that evidence of burglary was “undisputed,” 78 N.J. 454, 396 A.2d 1122 (1979) (internal citations omitted) (emphasis added in original).]
“[T]he question whether an error is reason for reversal depends finally upon some degree of possibility that it led to an unjust verdict.” State v. Macon, 57 N.J. 325, 335, 273 A.2d 1 (1971). “[U]pon that question the reviewing judge [is] inevitably remitted to his [or her] own conscientious judgment.” Id. at 338, 273 A.2d 1. This Court has sought to prevent overuse of the “harmless error” doctrine. In State v. Czachor, 82 N.J. 392, 404, 413 A.2d 593 (1980), the Court explained that “errors which impact substantially and directly on fundamental procedural safeguards ... are not amenable to harmless error rehabilitation.” As stated in State v. Simon, 79 N.J 191, 206, 398 A.2d 861 (1979): “Errors impacting directly upon ... sensitive areas of a criminal trial are poor candidates for rehabilitation under the harmless error philosophy .... ” For this reason, the rule of harmless error should be summoned only with great caution in dealing with the breach of fundamental procedural safeguards “designed to assure a fair trial.” (Citations omitted). “There is widespread agreement that other-crime evidence has a unique tendency to turn a jury against the defendant. The likelihood of prejudice is acute when the proffered evidence is proof of a defendant’s uncharged misconduct.” State v. Stevens, supra, 115 N.J. at 302, 558 A.2d 833.
Finally, even if the evidence had been admissible on the subsidiary issues in the case, the charge in this case left the jury wholly unguided as to how to use the evidence for such limited purposes. An erroneous charge will rarely stand on the ground that it was harmless, error. State v. Weeks, 107 N.J. 396, 410, 526 *263A.2d 1077 (1987). Although reviewing courts are ordinarily reluctant to reverse on the ground of plain error when no objection to the charge has been made, it has been “repeatedly emphasized that incorrect instructions of law are poor candidates for rehabilitation under the harmless error theory.” Ibid, (citations omitted). These well-settled principles compel the conclusion that defendant’s conviction must be reversed and the matter remanded for a new trial. In reversing the defendant’s conviction in Oliver, the Court distinguished the cases in which instructional errors had been found to be harmless:
By contrast, the trial court in this case did not explain the relationship between the other-crime evidence and the issues and facts on which it could be considered. Although the court did clearly instruct the jury that it was not to use the evidence to determine that defendant was a bad person or that he had been disposed to commit the crimes charged in the indictment, it did not clewrly instruct the jury on how it could use the othar-crime evidence. Precisely that situation prompted this Court to find reversible error in Cofield.
[State v. Oliver, supra, 133 N.J. at 158-59, 627 A.2d 144 (emphasis added).]
IV
Although, then, we agree with the Appellate Division that the other-crime evidence was irrelevant to the aggravated sexual assault charge and inadmissible on that count, the evidence does have relevance to one of the defenses raised by defendant at trial. It was a theory of the defense that Laura’s story of sexual molestation was fabricated by Laura as revenge for her father’s having abandoned her mother and her anger over his having come to the home with a new girlfriend. Evidence is relevant if it tends “to prove or disprove any fact of consequence to the determination of the action.” N.J.B.E. 401. In determining whether evidence is relevant, the inquiry should focus on the “logical connection between the proffered evidence and a fact in issue.” State v. Hutchins, 241 N.J.Super. 353, 358, 575 A.2d 35 (App.Div.1990), and “whether the [evidence offered] ‘renders the desired inference more probable than it would be without the evidence.’ ” State v. Davis, 96 N.J. 611, 619, 477 A.2d 308 (1984) (quoting State v. Deatore, 70 N.J. 100, 358 A.2d 163 (1976)).
*264If the evidence offered makes the inference to be drawn more probable, then the evidence should be admitted unless otherwise excludable by a rule of law. Biunno, Current N.J. Rules of Evidence, comment 1 on N.J.R.E. 401 (1998-1999). The fact in issue is bias on the part of Laura. Does Linda’s testimony make it more probable that Laura’s testimony was not the product of bias? In some sense Linda’s testimony is similar to that which was offered in Stevens, supra, 115 N.J. at 295-97, 558 A.2d 883. Recall that in Stevens a police officer was charged with official misconduct involving strip searches of arrested women that were motivated by the officer’s desire for sexual gratification. The State presented evidence of previous incidents in which the officer induced other female arrestees to undress or provide sexual favors. If the testimony of the other women in Stevens had a tendency in reason to make more probable the inference that the strip searches had a purpose other than law enforcement, the testimony of another daughter in this case would appear to make it more probable that bias was not the motivation for Laura’s testimony. Put another way, is it logical to conclude that two daughters would be less likely to trump up testimony than one? See also State v. G.S., supra, 145 N.J. at 475, 678 A.2d 1092 (holding that evidence of uncharged prior sexual assaults on the same victim were admissible as bearing on the credibility of the victim).
The difficulty in using the other-crime evidence to assess bias on the part of the child-victim in this case is that bias of the witness because of a’ vendetta against the father is not, in the first instance, a material issue that is genuinely in dispute. It is only when defendant puts the bias of the witness (on account of a vendetta) into issue that the evidence would be admissible. If, at the hearing prior to trial under Evidence Rule 104, defendant disclaims the use of the vendetta defense, the State would have no basis for admitting the evidence. On the other hand, if defendant renews the vendetta defense, it appears to us that the testimony of the older sister is relevant to show that the testimony of Laura is not the product of bias. Of course, the trial court would have to *265complete the Marrero analysis, balancing the probative worth of the evidence against its prejudicial effect. (Not all members concurring in Part IV would require the probative-prejudice analysis, Coleman, J., concurring, post at 281, 744 A.2d at 154, but we believe that the trial court should do the complete analysis in light of the revised purpose for which the evidence is to be offered.) The State also suggests that the other-crime evidence might be relevant to establish the disputed fact of access or the opportunity to have been alone with the child. See State v. Oliver, supra, 133 N.J. 141, 627 A.2d 144 (discussing relevance of prior sexual attacks on women in an upstairs apartment when defense of feasibility was asserted). The issue of feasibility, however, was not “genuinely in dispute,” Marrero, supra, 148 N.J. at 482, 691 A.2d 293, and, unless it is genuinely disputed on retrial, cannot provide a basis for admission of the other-crime evidence.
The judgment of the Appellate Division is affirmed. The matter is remanded to the Law Division for further proceedings in accordance with this opinion.