¶1*782Daniel B. Silver, Washington, D. C., with whom Thomas C. Hill, Washington, D. C., was on brief, for appellant.
¶2Charles R. Donnenfeld, Washington, D. C. , with whom Paul A. Kaplan, Washington, D. C., was on brief, for appellees.
¶3Before ROBINSON, MacKINNON and ROBB, Circuit Judges.
¶4Opinion for the court filed by MacKINNON, Circuit Judge.
¶5Concurring opinion filed by SPOTTSWOOD W. ROBINSON, III, Circuit Judge.
¶7This case presents an appeal from a jury verdict finding that appellant had not been the victim of racial discrimination during the course of his tenancy, and subsequent eviction, from the luxury Crestwood Apartments located in Washington, D. C. Appellant, Green Miller, filed suit seeking compensatory, punitive and injunctive relief under the (1) Thirteenth Amendment, (2) section one of the Civil Rights Act of 1866, now codified as 42 U.S.C. § 1982 (1970), (3) section 16 of the Civil Rights Act of 1870, now codified as 42 U.S.C. § 1981 (1970), and (4) the Fair Housing Act of 1968, 42 U.S.C. § 3601et seq. (1970). At trial, the appellant introduced evidence of a number of incidents allegedly indicative of racial discrimination, and the appellee landlord countered this evidence — most of which involved various altercations with Crestwood personnel and fellow tenants — with testimony explaining these incidents as caused more by Miller’s own obstreperous behavior than by any racial bias on the part of the appellees.
¶8In this appeal, we are not concerned with the details of the factual issues which the jury at trial clearly determined were more accurately portrayed by the landlord than by appellant. We are confronted solely with three grounds on which appellant claims the verdict below should be overturned and a new trial ordered: (1) an allegedly erroneous evidentiary ruling, (2) a denial of collateral estoppel, and (3) a refusal of a requested instruction. We find that the lower court did commit error in its evidentiary ruling, but that such error was harmless, and that its denial of collateral estoppel and its refusal of appellant’s proposed instruction were not erroneous. Accordingly, we affirm the judgment below in all respects.
¶9I
¶10THE EVIDENTIARY RULING
¶11At the trial, appellant wished to introduce evidence of alleged incidents of discrimination involving other Crestwood tenants similar to those which he himself claimed to have suffered. The . District Court refused to admit this evidence (only one incident was actually proffered, that of a one Horan, although appellant alludes to the existence of several others). The trial court did not specify its reasons for exclusion of Horan’s testimony, but appellees argue here that the court's ruling was adequately supported by Federal Rule of Evidence 403:
Although relevant, evidence may be excluded if its probative value is substantially outweighed by the danger of unfair *783prejudice, confusion of the issues, or misleading the jury, or by considerations of undue delay, waste of time, or needless presentation of cumulative evidence.
¶12Appellees insist that evidence of incidents of discrimination concerning parties other than Mr. Miller were properly excluded by the trial court in the exercise of its discretion, because not only would demonstrating that actual discrimination had taken place in such incidents have required extensive investigation of collateral issues, but also because evidence of such incidents — although probative of the motive of the landlord in dealings with the appellant1 — would have been excessively prejudicial to the appellee.2
¶13It is unquestionably the case, in this circuit and elsewhere, that the trial judge’s weighing of evidence against the criteria of Rule 403 is a matter within his discretion and will only be overturned on appeal for abuse, e. g., United States v. Wright, 160 U.S.App.D.C. 57, 62, 489 F.2d 1181, 1186 (1973); Kilarjian v. Horvath, 379 F.2d 547, 548 (2d Cir. 1967); Hardy v. United States, 118 U.S.App.D.C. 253, 254, 335 F.2d 288, 289 (1964). We are naturally reluctant to disturb a trial judge’s ruling on an evidentiary matter such as this, and we recognize that problems of prejudice and time-consuming examination of collateral issues are present, nevertheless we conclude for several reasons that it was error to exclude this testimony.
¶14First, the court did admit testimony of black witnesses for the appellees asserting that they had not suffered racial discrimination at Crestwood. Such testimony was the counterpart of that which the appellant wished to introduce through Horan, and elementary fairness would require that if the appellee could bring in such evidence, the appellant should have been allowed to do so also. The trial court in making its ruling on this matter alluded to the fact that appellees had only put on witnesses serving to rebut Mr. Miller’s own statement in open court,3 but this rationale proves little. Clearly the testimony of third persons would be more persuasive in the jury’s eyes than that of the appellant himself, and he should have been entitled — if he were able — to rebut the landlord’s defense of a non-discrimination motive by the same apparently disinterested evidence that appellees were allowed to use to rebut appellant’s claim of racial animus.
¶15It is hard to see how appellant’s evidence of possible discrimination against Horan and possibly others would tend to embroil the court in investigation of collateral issues any more than would appellees’ evidence of non-discrimination. It is likely, however, that the former would involve a substantially higher risk of prejudice. This danger, however, seems outweighed by the fact that at the pretrial conference, the district judge gave appellant good reason to believe that he would be entitled to admit testimony concerning alleged acts of discrimination against others. At this conference, the following exchange took place concerning the status of such evidence:
MR. DONNENFELD. Your Honor, I would suggest that, if I know the evidence here, if they call another tenant not affiliated with Mr. Miller who says *784that they also had some problem; they were once chewed out by the landlord, and they view that as a racial matter, I can’t see how that is in any way probative of the landlord’s actions toward Mr. Miller vis-a-vis Mr. Miller.
MR. HEARITY. It is certainly relative as to motive, Your Honor.
MR. DONNENFELD. What does what the defendants did to tenant “X” have to do with their motives vis-a-vis Mr. Miller?
MR. GARLAND. If the landlord did to tenant “X” a certain act because of his race and his race is, in fact, the same race as Mr. Miller’s then you can also say that his motive for acting toward Mr. Miller was due to Mr. Miller’s race.
MR. DONNENFELD. What about the 200 tenants who are black and did not have the same experience?
MR. GARLAND. No. 1, there were not 200 other blacks who were tenants. At this time we are talking about 19 other tenants who are black. They can testify to the fact that they were not discriminated against because of their race.
MR. HEARITY. This, we believe, apart from any pattern and practice theory, is relevant evidence to make the fact that Mr. Miller was discriminated against on the basis of his race more likely to be true.
We think it is relevant. The witnesses will be short.
THE COURT. All right.
I will let you, over the objection of Mr. Donnenfeld, so the record is clear, present evidence with respect to pattern and practice, but that has to be limited, in fairness to the defendants, certainly to no more than the Crestwood Apartments. Do you not agree?
MR. HEARITY. Yes, Your Honor.
MR. DONNENFELD. Your Honor, may we ask that it be limited to the types of alleged discriminatory acts that were visited on Mr. Miller?
THE COURT. I think that is a fair caveat, and I don’t think the plaintiffs will object to that, either.
MR. HEARITY. We will not, Your Honor, depending on the definition of “discriminatory acts visited upon Mr. Miller.” If you are talking about unfounded complaints of this, that or the other thing—
THE COURT. I think we can settle that, as my law clerk just mentioned, when the problem comes up at trial.
¶16J.A. 45-46.
¶17It appears from this transcript that the district judge had agreed, or at least misspoke in such a way as to lead appellant justifiably to believe that he had agreed, to admit into evidence instances of other tenants’ experience of the “types of alleged discriminatory acts that were visited on Mr. Miller.” The excluded testimony involved a claim that the landlord had refused to rent to a black (Horan), one of the grievances appellant himself had asserted against appellees.4 Thus, it appears that appellant had legitimate grounds to expect that such testimony would be allowed. A judge is not absolutely bound by representations at the pretrial conference, but representations made at that time should only be reneged upon with great reluctance, usually only to prevent manifest injustice, e. g., Manbeck v. Ostrowski, 128 U.S.App.D.C. 1, 384 F.2d 970 (1967), cert. denied, 390 U.S. 966, 88 S.Ct. 1077, 19 L.Ed.2d 1170 (1968). We find no such justification in this case, and feel that the possible damage the trial court’s unexpected exclusion did to appellant’s case outweighed any reasonable fear of prejudice to the appellees from introducing such evidence.
¶18In summary, it is clear that the proffered evidence of past acts of racial discrimination was relevant to prove the landlord’s motive in his action towards appellant, the risk of time-consuming collateral inquiries *785was no more present in admitting appellant’s evidence of such past incidents than in admitting appellees’ similar testimony; and the danger of prejudice to the appellees was over-balanced by the detrimental effect of the exclusion on appellant’s presentation. On the whole, the admission of appellees’ witnesses testifying to their freedom from discrimination and the exclusion of appellant’s witness testifying to the contrary was, particularly in light of the colloquy at the pretrial conference, that sort of decision which traditionally has been considered an abuse of discretion, e. g., Burns v. United States, 287 U.S. 216, 223, 53 S.Ct. 154, 77 L.Ed. 266 (1932); Langnes v. Green, 282 U.S. 531, 51 S.Ct. 243, 75 L.Ed. 520 (1931); The Styria, 186 U.S. 1, 9, 22 S.Ct. 731, 46 L.Ed. 1027 (1902); Poske v. Mergl, 169 Ohio St. 70, 157 N.E.2d 344 (1959). We also concur in Judge Robinson’s separate opinion which further explicates the law on these issues.
¶19II
¶20The erroneous nature vel non of the district court’s evidentiary ruling need not further detain us, however, as whether or not this ruling was erroneous it must also be prejudicial in order to merit reversal. Errors only lead to an overturning of the verdict reached at trial when such errors “affect the substantial rights of the parties,” 28 U.S.C. § 2111 (1970); e. g., International Merger & Acquisition Consultants, Inc. v. Armac Enterprises, Inc., 531 F.2d 821 (7th Cir. 1976); Anderson v. Breazeale, 507 F.2d 929 (5th Cir. 1975), and we feel that no such rights have been affected here. That the appellees might have been shown, had the excluded testimony been admitted, to have evinced a discriminatory motive in dealing with other members of Mr. Miller’s race is relevant to the question of whether or not their motive was to act in a similar fashion towards Mr. Miller. However, the facts surrounding the other alleged incident of discrimination are too indefinite, and appellees’ counter-explanations for their behavior towards appellant involving no racially discriminatory motive are sufficiently compelling that we find it highly improbable that the jury would have made an affirmative finding that Miller had been discriminated against, even if the evidence proffered had been admitted, see Schneble v. Florida, 405 U.S. 427, 430-432, 92 S.Ct. 1056, 31 L.Ed.2d 340 (1972); Harrington v. California, 395 U.S. 250, 251-254, 89 S.Ct. 1726, 23 L.Ed.2d 284 (1969); Chapman v. California, 386 U.S. 18, 24, 87 S.Ct. 824, 17 L.Ed.2d 705 (1967).
¶21Moreover only one incident was proffered by appellant and on its face that was inconclusive to establish racial animus. The excluded testimony would have shown that when two male police cadets, one white and one black, applied for an apartment in Crestwood, the white officer was told by an appellee: “If you come back alone, you will get it, but not your buddy.”5 This statement might well indicate racial prejudice, but it also might simply indicate that single person units were the only apartments available, or that there was a building policy against allowing two unmarried men to share an apartment together. Or there may have been other valid reasons to object to the second man. The possibility of such other factors would at least reduce the impact of the evidence even if they did not serve to vitiate it entirely. Moreover, even assuming that the excluded testimony proved unequivocally that a discriminatory motive was in fact at work in that ease, the probative value of such evidence is intrinsically low. That the landlord had discriminated in another instance would, of course, suggest that he was biased against blacks in general, but there is no necessary connection between such a generalized sentiment and the question of whether or not appellant himself was the victim of discrimination. In light of the rapidly growing number of blacks at Crestwood during the time of Mr. Miller’s tenancy there,6 the testimo*786ny of other blacks that they had not experienced unequal treatment, and the considerable evidence tending to show that the landlord’s actions against appellant had been no more than reasonable responses to the latter’s outrageous behavior,7it is hard to believe that “the average jury” would be swayed in its decision by evidence of an isolated instance of racial discrimination not-even involving Mr. Miller. See Schneble v. Florida, supra; Harrington v. California, supra; Chapman v. California, supra; Gray v. Gray, 459 P.2d 181 (Okla.1969); State Bank of Arthur v. Sentel, 10 Ill.App.3d 86, 293 N.E.2d 444 (1973). Appellant’s conduct was so egregious that no landlord attempting to run an orderly apartment house would have failed to take the same action as Poretsky. We agree with the appellant that the exclusion of the evidence proffered was erroneous, but we cannot agree that this exclusion altered the outcome of the case, or that Mr. Miller was denied a fair trial by the district court’s action in this regard, because the evidence showed he was heedless of apartment regulations and a highly objectionable tenant, see Bruton v. United States, 391 U.S. 123, 135, 88 S.Ct. 1620, 20 L.Ed.2d 476 (1968), quoting Lutwak v. United States, 344 U.S. 604, 619, 73 S.Ct. 481, 97 L.Ed. 593 (1953).
¶22Ill
¶23THE DENIAL OF COLLATERAL ESTOPPEL
¶24Appellant’s second contention is that the district court should have given collateral estoppel effect to the judgment of the District of Columbia Court of General Sessions in which a jury, in an eviction action by appellee landlord against Miller based on an alleged assault by the latter on his building’s receptionist, determined that Miller could not be evicted. The issue that the jury was instructed to decide in arriving at its verdict was whether “the defendant committed an assault and battery upon an employee of the landlord, and the conduct has not been waived by the landlord.”78
¶25During the trial of the instant suit, appellees introduced testimony of the allegedly battered receptionist concerning appellant’s attack on her. The court refused to consider the earlier decision of the Court of General Sessions as conclusively establishing that no battery had occurred, and also refused to instruct the jury that another court had found Miller innocent of assault and battery.
¶26There was no error in the court’s ruling on this point. Extending collateral estoppel effect to the verdict in the eviction proceeding would have been improper because the issue involved in that litigation and the one currently before us are by no means identical. It was not important to the suit in district court whether or not Mr. Miller had in the full legal sense assaulted or battered the receptionist at Crestwood. Evidence concerning the incident was only relevant in that it tended to show that the alleged acts of discrimination were in fact motivated by appellant’s own behavior. In this regard, the fact that another court had previously found that the appellant could not be evicted because he had not actually assaulted the receptionist is at best of only ambiguous significance. The difference between the issues is such that collateral estoppel was inappropriate, as it cannot be asserted that the question of whether or not Miller harassed the receptionist was litigated and decided in the earlier case, Stebbins v. Key*787stone Insurance Co., 156 U.S.App.D.C. 326, 331, 481 F.2d 501, 506 (1973); Developments in the Law: Res Judicata, 65 Harv.L.Rev. 818, 849 (1952). Moreover, it cannot be said that the judgment of the Court of General Sessions necessarily included a finding that Mr. Miller had not been obstreperous to his receptionist, United Shoe Machinery Corp. v. United States, 258 U.S. 451, 459, 42 S.Ct. 363, 66 L.Ed. 708 (1922); Tutt v. Doby, 148 U.S.App.D.C. 171, 173, 459 F.2d 1195, 1197 (1972). The Supreme Court has made clear that collateral estoppel must be construed narrowly to apply only to instances where there has been “an adjudication on the merits”, United States v. International Building Co., 345 U.S. 502, 506, 73 S.Ct. 807, 97 L.Ed. 1182 (1953), and generally only to “issues actually litigated and determined in the pri- or suit,” Lawlor v. National Screen Service Corp., 349 U.S. 322, 326, 75 S.Ct. 865, 867, 99 L.Ed. 1122 (1955). We feel no hesitation in determining that such estoppel was inappropriate in this case.
¶27As for the district court’s refusal to instruct the jury that Miller had been found not guilty of assaulting the employee, we find no error in this refusal. Once a jury has been fairly and adequately instructed, the requirements of the law are satisfied, Piechoski v. Grace Lines, Inc., 409 F.2d 66 (3d Cir. 1969); Lind v. Aetna Casualty & Surety Co., 374 F.2d 377 (5th Cir. 1967). There is no doubt here that the instructions adequately presented the issues to be resolved by the jury. The requested “instruction” was not so much an instruction as an additional piece of evidence which appellant wanted presented to the jury with the special imprimatur of a judicial pronouncement. The trial judge may well justifiably have feared that instructing the jury that appellant had been found not guilty of assaulting the receptionist would have had a dispositive, quasi-collateral estoppel effect which it did not merit, for the same reasons that collateral estoppel itself was inappropriate. The judge did not err in refusing appellant’s request.
¶28Appellant was not foreclosed by the denial of collateral estoppel or the refusal of his requested instruction from having an ample opportunity of giving his version of the incident with the receptionist, nor from attempting to impeach her testimony. The trial court’s ruling served only to ensure that the issue of appellant’s abuse of a Crestwood employee would be heard in the trial of the latter’s suit alleging that he had himself been abused by the management of Crestwood. The district court’s ruling in this regard, far from unfairly prejudicing appellant’s case, served only to ensure that the full merits of the question at issue were fairly presented to the jury.
¶29IV
¶30THE REFUSAL OF APPELLANT’S REQUESTED INSTRUCTION
¶31Appellant’s final contention is easily disposed of. He objects to the trial court’s instruction concerning what the jury must find in order to return a verdict favorable to him on the charge of racial discrimination. The instruction as given stated:
The first element of liability that the plaintiff has the burden of establishing, as I said before, by a preponderance of the evidence, is that these defendants treated Mr. Miller differently than they would have treated a white person under the same or similar circumstances.9
¶32Whereas the instruction requested by the appellant was designed to be somewhat more explicit concerning the point that the jury need not find that racial discrimination was the sole reason for the landlord’s alleged mistreatment of the appellant in order to award the latter damages:
¶33Requested Instruction No. 10 Racial and Non-Racial Motivation
In order for you to return a verdict for plaintiff, it is not necessary for you to find that defendants’ actions were based solely on racial discrimination. It is sufficient if you find that plaintiff’s race played some part in defendants’ actions *788toward him. Even if you find that plaintiff violated established rules and regulations of the Crestwood, if you also find that these rules and regulations would not have been applied to plaintiff had he been White, or would have been applied less strictly, then you must find for plaintiff. In reaching this determination, you should consider the evidence relating to defendants’ racial attitudes as well as all other evidence in the case.
Authority.
Moore v. Townsend, 525 F.2d 482 (7th Cir. 1975); Smith v. Sol D. Adler Realty Company, 436 F.2d 344 (7th Cir. 1971);
Stevens v. Dobs, Inc., 483 F.2d 82 (4th Cir. 1973); Langford v. City of Texarkana, Arkansas, 478 F.2d 262 (8th Cir. 1973);
Steele v. Title Realty Company, 478 F.2d 38 (10th Cir. 1973);
Williamson v. Hampton Management Co., 339 F.Supp. 1146 (N.D.Ill.1972);
McDonnell Douglas Corp. v. Green, 411 U.S. 82, 93 S.Ct. 1817, 36 L.Ed.2d 668 (1973);
Taylor v. Safeway Stores, Inc., 365 F.Supp. 468 (D.Col.1973).
¶34Appellant and the district judge did not in fact disagree over the legal standard to be applied; nor do appellees suggest that appellant was wrong in maintaining that as long as race was any factor influencing the landlord’s dealing with appellant that appellant was entitled to recover. The trial court simply chose to phrase the appropriate legal standard somewhat differently, admittedly less emphatically, than appellant would have liked. As long as a district judge’s instructions are legally correct, however, he is not required to give them in any particular language, even when this language has been copied directly from Supreme Court opinions, which Miller’s certainly was not, Wolff v. Comm’r of Puerto Rico, 341 F.2d 945 (1st Cir. 1965); Dupont v. Southern Pacific Co., 366 F.2d 193 (5th Cir. 1966), cert. denied, 386 U.S. 958, 87 S.Ct. 1027, 18 L.Ed.2d 106 (1967). Appellant claims that the court’s instruction “certainly left the impression that in order to find for the plaintiff it at the least was required to find that the racial motivation of defendants preponderated over other considerations,” but even a cursory reading of these instructions demonstrates that this criticism is unfounded. The trial judge correctly informed the jury that they must find by a preponderance of the evidence that racial prejudice was at least one factor influencing appellees’ actions. This is the law, not error, and appellant had no right to ask for more.
¶35Having determined that the error the trial court did in fact make did not deny appellant a fair trial, and that the other grounds for appeal are meritless, we affirm the judgment of the district court.
¶36So Ordered.
¶47concurring:
¶48I am in full accord with Parts II and III of the court’s opinion, and with the court’s conclusion in Part I that the District Judge erroneously excluded Horan’s testimony to an incident that the jury could have interpreted as an act of racial discrimination by appellees against someone other than appellant. I also agree that, in the circumstances of the case, the ruling was not sufficiently prejudicial to require reversal, and that appellant cannot prevail on any other contention he now presses. I wish to emphasize, however, that our holding today is that rejection of this testimony could not be sustained as an appropriate exercise of judicial discretion even absent the compounding effect of two other trial occurrences — the admission of evidence of nondiscrimination proffered by appellees, and the District Judge’s pretrial statement that appellant would be permitted to put on evidence indicating discrimination by appellees against others. In other words, admission of the challenged testimony was required even if it had not b.een aided by these additional factors.
¶49*789Resolution of the evidentiary issue is somewhat handicapped by the fact that, as my colleagues recognize, “[t]he trial court did not specify its reasons for exclusion.”1 Appellees contend2 that Horan’s testimony was kept out as a matter of trial-court discretion in the balancing function summoned by Federal Evidence Rule 403:
Although relevant, evidence may be excluded if its probative value is substantially outweighed by the danger of unfair prejudice, confusion of the issues, or misleading the jury, or by considerations of undue delay, waste of time, or needless presentation of cumulative evidence.3
¶50While it is possible to deduce from the record that the District Judge utilized Rule 403 in barring the testimony,4 the record more readily supports the inference that the theory underlying exclusion was irrelevance.5 But whatever the rationale assumed by the judge as the basis for his action, the ruling cannot pass muster.
¶51I
¶52In pertinent part, the Fair Housing Act6 declares unequivocably that
¶53it shall be unlawful—
(a) To refuse to . rent after the making of a bona fide offer . or make unavailable · Case Law">otherwise make unavailable or deny, a dwelling to any person because of race [or] color
(b) To discriminate against any person in the terms, conditions, or privileges of . rental of a dwelling . . . because of race [or] color . . .7
¶54No one suggests that the case before us is exempt from these provisions,8 nor can it be *790gainsaid that conduct described by the Act transgresses its terms when motivated by considerations of race or color.9 So, in the case at bar, proof that appellees acted with racial animus in taking the complained-of actions against appellant would clearly have been sufficient, though possibly not essential,10 to establish a violation of the Act. The question, then, is whether Horan’s testimony was competent and relevant on that score.
¶55There is no doubt whatever that the answer must be in the affirmative. Rule 404(b) provides that “[e]vidence of other . acts . . . may ... be admissible [to prove] motive [or] intent.”11 This canon incorporates a longstanding and broadly operative principle,12 and there is *791no reason why it should not apply here. As ' the court’s opinion states, “it is clear that the proffered evidence of past acts of racial discrimination was relevant to prove the landlord’s motive in his action towards appellant.” 13
¶56This conclusion finds ample support in the caselaw, perhaps nowhere more strongly than in the Supreme Court’s decision in McDonnell Douglas Corp. v. Green,14wherein the Court delineated “the order and allocation of proof in a private, non-class action challenging employment discrimination.”15 After the plaintiff has carried the initial burden of establishing a prima facie case of racial discrimination,16 said the Court, the burden shifts to the defendant “to articulate some legitimate, non-discriminatory reason” for his conduct.17 If that reason sufficiently meets the plaintiff’s prima facie case, the plaintiff must then “be afforded a fair opportunity to show that [the defendant’s] stated reason for [his actions] was in fact pretext.”18 Very importantly for the case before us, the Court specifically noted that “[o]ther evidence that may be relevant to any showing of pretext includes facts as to . [the defendant’s] general poli*792cy and practice with respect to minoritpes].”19
¶57Relying on McDonnell Douglas, we recently held in Kinsey v. First Regional Securities, Inc.,'20 a discrimination suit brought by but one individual, that exclusion of “evidence of hiring practices and statistical data” 21 on grounds of irrelevance constituted reversible error even though the evidence related to different jobs and different time periods from those cited in the plaintiff’s complaint.22 Moreover, the McDonnell Douglas-Kinsey approach to the admissibility of other-acts evidence23 has been endorsed by numerous other courts in nonclass employment-bias24 and fair-housing25 actions. So commonly has other-acts evidence been utilized in individual nonclass discrimination suits that courts frequently admit it without any felt need to elucidate a rationale for their actions.26
¶58*793In several nonclass housing discrimination cases, evidence nearly identical to that offered here has been admitted as clearly relevant. In Smith v. Anchor Bldg. Corp.,27 the plaintiff, suspecting that she had been denied an apartment because she was black, enlisted the aid of a local civil rights organization. The latter dispatched to the apartment complex in question a white “checker,”28 whose “function ... in this context was to compare rental procedures as applied to black and white persons.”29 The checker’s observations were let in, the Eighth Circuit noting on appeal that such activity “has been uniformly admitted into evidence to show the existence of discrimination.” 30 Evidence of a nearly contemporaneous rejection of another black applicant was also received, the Court of Appeals remarking that it was “highly probative.” 31
¶59Similarly, in Wharton v. Knefel,32 evidence showing that a defendant landlord had offered to lease an apartment to a prospective black tenant a year and a half before she turned the also-blaek plaintiff down was considered in arriving at the conclusion that the plaintiff was not denied housing on the basis of race.33 And in Bishop v. Pecsok,34evidence disclosing that a landlord had informed another black applicant that he did not rent to blacks was relied upon to support the court’s holding that rejection of the black plaintiff’s application was founded on race.35
¶60Perhaps these examples might be multiplied, but more is hardly necessary. The probative value of other-acts evidence in nonclass discrimination suits is satisfactorily established. Exclusion of Horan’s testimony to appellees’ discriminatory acts against others than appellant cannot be sustained on the notion that it was irrelevant.
¶61II
¶62For these reasons, evidence of this nature was entitled to a role in appellant’s effort to demonstrate appellees’ motive in treating him as they did. Appellees contend, however, that the decision on Horan’s testimony could nevertheless have been proper as an exercise of judicial authority under Rule 403.36 Although “the trial judge’s weighing of evidence against the criteria of Rule 403 is a matter within his discretion,”37 there are limits on the discretion conferred by Rule 403,38 and irredeemably they were exceeded here.
¶63To begin with, any grant of discretion contemplates that it will be exercised — one way or the other — when the situation giving it birth makes its appearance. Beyond that, discretion is abused if clearly probative evidence is excluded when there is virtually no danger of unfair prejudice, issue-confusion or other Rule 403 factors militat*794ing against admission.39 Scrutinizing this case within these limits, it must first be noted that there is nothing on the record before us to indicate that the District Judge ever drew upon his Rule 403 discretion — by weighing appropriate factors40 — in concluding that Horan’s testimony was inadmissible,41 and that the uncertainty in this regard could be removed only by a remand with instructions to explicate the reasons for concluding that exclusion was in order.42 There is no need for that, however, for, even assuming that the judge actually endeavored to strike the balance required by Rule 403, exclusion was erroneous under the abuse-of-discretion standard.
¶64*795Appellees contend,43 that the probative value of Horan’s testimony was outweighed by its prejudicial proclivity. The difficulty in that position is that the prejudice to which Rule 403 speaks is something utterly different from the capability of the evidence to debilitate the opponent’s cause in an entirely legitimate manner. The prejudice that Rule 403 specifies as a factor working against the admission of relevant evidence is “unfair prejudice,”44 and “ ‘[ujnfair prejudice’ . . . means an undue tendency to suggest decision on an improper basis, commonly, though not necessarily, an emotional one.”45 Though arguably, as appellees claim,46 Horan’s testimony might have engendered some chance that the jury might penalize appellees for discriminating against someone other than appellant, its exclusion could not possibly have been justified in the face of the much more powerful considerations on the other side. Horan’s testimony had no special attribute of unfair prejudice that would distinguish it from the general body of other-acts evidence thought to be so relatively free of a potential for unfair application that courts routinely admit it in nonclass discrimination suits without any discussion of prejudice.47 Remoteness of the danger to which appellees advert is further attested by the fact that they cite no case — -nor have we found any — in which evidence of this kind was excluded on the basis of unfair prejudice. Doubtless that is because the evidence not only is relevant, as everyone concedes, but is the only indication— other than the defendant’s say-so — of what his state of mind might have been when he acted.48
¶65Rule 403 does not precondition the admissibility of other-acts evidence upon a guaranty that its use by the jury will be impeccable. It recognizes fully the value of limiting instructions, and contemplates that “[i]n reaching a decision whether to exclude on grounds of unfair prejudice, consideration [will] be given to the probable effectiveness or lack of effectiveness of a limiting instruction.”49 No reason whatever is suggested as to why in the instant case the already miniscule risk that the jury might go astray could not have been acceptably mitigated, if indeed not eradicated, by an instruction confining the jury’s utilization of Horan’s testimony specifically to the issues of intent and motive on which it was sought to be admitted.
¶66Finally, appellees also suggest that Horan’s testimony could properly have been excluded because it would have interjected collateral issues likely to confuse or mislead the jury and waste time.50 Here again, no case in which other-acts evidence was rejected on this premise has been uncovered. Quite to the contrary, in Corley v. Jackson Police Department51the Fifth Circuit held flatly that such evidence properly directed does not pose the hazard of collateral disputes:
It is apparent . . . that the district court . . . viewed all evidence relevant to pretext — the treatment of other officers similarly accused . and the history of racial discrimination within the Jackson police — as ‘collateral questions’ . . . . But under McDonnell Douglas, such evidence is not merely collateral; it is an indispensable element of the plaintiff’s burden of proof and must be confronted by the district court in finding for either party. Such evidence does not becloud any issue in this case; rather, it directly addresses and *796sharply defines a key issue, as developed in McDonnell Douglas and its progeny.52
¶67Ill
¶68As an eminent jurist once observed, under certain conditions a decision normally committed to a trial court’s discretion may become the subject of a judicial rule:
Several of the most important reasons for deferring to the trial judge’s exercise of discretion — his observation of the witnesses, his superior opportunity to get ‘the feel of the case,’ see Cone v. West Virginia Pulp & Paper Co., 330 U.S. 212, 216, 67 S.Ct. 752, 91 L.Ed. 849 (1947), and the impracticability of framing a rule of decision where many disparate factors must be weighed, see Atchison, T. & S.F. Ry. v. Barrett, 246 F.2d 846 (9th Cir. 1957) — are inapposite when a question arising in advance of trial can be stated in a form susceptible of a yes-or-no answer applicable to all cases. . . . 53
¶69And as a discerning commentator has similarly noted, a primary reason for a policy of deference is that the issues involved are of such character that they do not lend themselves to sound resolution by application of a general rule.54 The frequency with which other acts evidence has been admitted in discrimination cases without question or apparent ill consequences suggests that a judicial rule favoring its normal admission has arisen already de facto. However that may be, at the very least a failure to follow clear precedent in an unexceptional case falls fatally short of a sound exercise of judicial discretion.
¶70An important public policy is subserved by admission of evidence of other acts of discrimination or nondiscrimination on the part of a defendant whose motivation vis-avis the plaintiff has been drawn into question. As the populace has become more and more aware of the illegality of disparate treatment attributable to racial or some other invidious classification, discriminatory practices have become increasingly subtle. Absent something amounting well nigh to an open admission of discriminatory purpose, victims may find it virtually impossible to prove that fact unless permitted to introduce evidence that the defendant has engaged in one or more acts of discrimination against others. At the same time, a defendant falsely accused of discriminating against the plaintiff should not be made to forego an opportunity to demonstrate lack of bias — more palatably than by his unsupported disavowal alone — by evidence reflecting nondiscriminatory activity on other occasions. These are wholly legitimate concerns when the operation of Rule 403 is subject to judicial inquiry. As the Advisory Committee has expressly stated, “[t]he availability of other means of proof may also be an appropriate factor” for consideration in instances implicating Rule 403.55 Here it should be given the prominence it is justly due.
¶71In sum, whether Horan’s testimony was excluded on a theory that it was irrelevant or that its probative value was outweighed by the likelihood of a prejudicial impact or the generation of collateral issues, the District Judge’s ruling cannot stand.56 Other *797trial occurrences enhanced the error in this ruling, but it was amiss even without those additional considerations. That is not to say that other-acts evidence can never be barred on grounds of prejudice or collateralness. It is to say that before it is rejected the record should show that it possesses characteristics presenting much more of a special and insuperable difficulty than appears here.