The opinion of the division, 356 A.2d 639, which we reconsider en banc, summarized the facts substantially as follows. Appellant and two codefendants were convicted by a jury of the armed robbery of a pastry deliveryman at gunpoint of a sum of money and two pies. A bystander copied the license plate number of the vehicle in which the robbers left the scene, and police stopped the car shortly thereafter. A passenger in the back seat, codefendant Harry Allen, attempted to flee, but was pursued and apprehended. The three persons who remained — appellant, the driver, and a front seat passenger — were ordered from the car. A search of the vehicle produced the two pies, and a gray coat said to have been worn by one of the robbers. Police found money in a pocket of the gray coat and on appellant’s person, and recovered a gun and a wallet from near the place where the fleeing passenger, codefendant Allen, was arrested. The deliveryman was unable to identify appellant as a participant in the robbery.

At trial, following the denial of appellant’s motion for judgment of acquittal, co-defendant Allen admitted his own direct involvement in the crime and gave exculpatory testimony on appellant’s behalf. He stated that during the robbery and its immediate aftermath, appellant had been incapacitated by the effects of narcotics withdrawal and was oblivious to the fact that a robbery was taking place.

In accordance with earlier advice to the court and defense counsel, and after laying a foundation on cross-examination, Allen was impeached by the testimony of the government’s rebuttal witness, Officer Bobby Collins, who testified that shortly after the arrest of appellant and his codefend-ants, Allen had made a statement to him denying his own active involvement and implicating appellant as a prime participant in the robbery. Appellant neither objected to the line of questioning nor requested an immediate instruction that such testimony could be considered only for a limited purpose. In its final charge to the jury, the trial court included a general instruction on the limited purpose for which evidence of a prior inconsistent statement could be used, but did not refer specifically to the testimony in question.

Appellant contends that the trial court erred in failing to immediately instruct the jury, sua sponte, that Officer Collins’ testimony describing Allen’s prior inconsistent statement was hearsay and thus could not be considered for the truth of its content but only to evaluate Allen’s credibility.1 A *1086majority of the division agreed with appellant, reversed the trial court, and held, on the authority of Lofty v. United States, D.C.App., 277 A.2d 99 (1971), that the trial court’s failure to give an immediate cautionary instruction, sua sponte, following admission of testimony of a prior inconsistent statement was plain error per se under Super.Ct.Cr.R. 52(b). Johnson, supra at 641. Upon reargument and reconsideration en banc, we conclude that the division majority’s reliance on Lofty was misplaced, and hold that appellant may not invoke the plain error rule to overcome his failure to object below. Accordingly, his conviction is affirmed.

The division majority, in arriving at the result which we now reverse, relied primarily on Lofty v. United States, supra. There, we held that a trial court’s failure, sua sponte, to immediately instruct the jury on the limited admissibility of a prior inconsistent statement introduced by the government to impeach its own witness, upon being surprised by his adverse testimony,2 was plain error requiring reversal. In so holding, we relied on a statement from United States v. McClain, 142 U.S.App.D.C. 213, 218, 440 F.2d 241, 246 (1971), that “whenever evidence [is brought in which is admissible] only for a limited purpose, it is plain error, in the absence of manifest waiver, to omit an immediate cautioning instruction.”

We now conclude that the opinion in Lofty unnecessarily and inappropriately broadened the scope of the plain error rule and ran afoul of the well-settled requirement that trial errors must be objected to at the time they occur if they are to be considered on appeal. Super.Ct.Cr.R. 30. Watts v. United States, D.C.App., 362 A.2d 706, 708-09 (1976) (en banc); Adams v. United States, D.C.App., 302 A.2d 232, 234-35 (1973); Dixon v. United States, D.C.App., 287 A.2d 89, cert. denied, 407 U.S. 926, 92 S.Ct. 2474, 32 L.Ed.2d 813 (1972); Wooten v. United States, D.C.App., 285 A.2d 308, 309 n. 3 (1971); Bunter v. United States, D.C.App., 245 A.2d 839, 841-42 (1968).3 In Watts v. United States, supra at 709, we explained that this requirement purported “to discourage the intentional withholding of objections by defense counsel,” see United States v. Curry, 358 F.2d 904, 912 (2d Cir.), cert. denied, 385 U.S. 873, 87 S.Ct. 147, 17 L.Ed.2d 100 (1966), and observed:

The obvious reason for requiring that objections to instructions be made before the jury retires is to afford the trial court an opportunity to correct any instructional defect and thereby avoid error which otherwise might necessitate a new trial. [362 A.2d at 708-09.]

The plain error rule invites a shrewd attorney who has a weak defense to conclude that his best strategic response to trial court errors is to remain silent, hoping thereby to “sow error in the record.” When *1087appellate courts readily grant relief under such circumstances by resort to the rule, they destroy the incentive of defense counsel to point out errors during the trial — a practice which is essential to a strong, adversary judicial system. We take this opportunity to make clear that there is a line beyond which we will not make an exception to the general rule that an unobjected-to error will not be noticed on appeal; otherwise resort to the exception will continue to expand endlessly until the exception becomes the rule. In the instant case, for example, a decision in one close case, Lofty, was relied on by the division majority as authority to extend the plain error exception to another but less justifiable situation.

Perhaps it was recognition of this that prompted us, in Dixon v. United States, supra, to limit severely the scope of Lofty. There we held, inter alia, that the trial court is not absolutely required, immediately after a defendant has been impeached by a prior conviction, to sua sponte instruct the jury on the limited use of the impeachment testimony. We said that we did not view the reference in Lofty to the above-cited statement from United States v. McClain, supra, “as controlling on facts not involving impeachment of one’s own witness by prior inconsistent statements.” 4 Dixon v. United States, supra at 97. We distinguished Lofty from the circumstances presented in Dixon, observing that “the high probability of jury confusion in the ‘prior inconsistent statement’ cases which required the exceptional use sua sponte of an immediate cautionary instruction by the trial court is not present in the case of ‘prior convictions’ evidence used for impeachment.” Dixon v. United States, supra at 99. We noted that while a per se instruction rule might be appropriate under circumstances in which the government claimed surprise at its own witnesses’ testimony and sought to introduce a prior inconsistent statement of that witness, such a rule was unnecessary where such surprise, and attendant jury confusion, was lacking.

The instant case is more analogous to Dixon than to Lofty. Like Dixon and unlike Lofty, the instant case involves impeachment by the government of a defense witness. Thus we do not have the situation presented in Lofty, in which the government, surprised by the testimony of its own witness, impeached that witness and thereby conceivably conveyed to the jury the impression that additional .substantive evidence was being offered. Such an impression is not as likely fostered when the government impeaches a defense witness, and the prejudice presumed in the Lofty situation just is not present.

In any event, we now hold that to the extent that it conferred on the trial court an absolute sua sponte obligation to issue an immediate cautioning instruction whenever evidence is brought in which is admissible only for a limited purpose, Lofty is overruled.5 We thus complete the assault on that decision begun in Dixon and continued, recently, in Watts v. United States, supra.6

*1088In so doing, we return to the long standing principle in this jurisdiction, from which Lofty and the cases on which it relied departed, that:

Except upon essential principles of law concerning which it is the duty of the trial judge to instruct the jury whether requested or not, there is no duty to instruct in the absence of a request. [George v. United States, 75 U.S.App.D.C. 197, 201, 125 F.2d 559, 563 (1942) (citations omitted).][7]

This is not to say that an appellate court should never recognize plain error or that it should affirm a judgment in the absence of timely objection where it is clear that appellant was denied a fair trial. Advice to the jury on the basic elements of the offense or on the standard of reasonable doubt are but two examples of factors not merely desirable but essential to a fair trial. Here, however, the defect was not of that nature. This court has the discretionary power to notice defects raised for the first time on appeal if substantial rights were clearly and prejudicially denied below.8

In Dixon v. United States, supra, we discussed the exercise of that discretion:

We believe that the wiser approach is to examine on a case by case basis the particular type of evidence sought to be introduced and then determine if an immediate cautionary instruction, sua sponte by the trial court, is required to prevent confusion on the part of the jury and thereby to protect the defendant’s interests. [Id. at 98.]

The fatal flaw in Lofty was its failure to appreciate that plain error is not the rule but is the exception to the rule. In applying Super.Ct.Cr.R. 52(b), supra note 8, the court neglected to apply Super.Ct.Cr.R. 30 which provides, in pertinent part:

No party may assign as error any portion of the charge or omission therefrom unless he objects thereto before the jury retires to consider its verdict, stating distinctly the matter to which he objects and the grounds of his objection.

Although Super.Ct.Cr.R. 30 is not controlling on this court we may, as with Rule 52, review errors in the exercise of our discretion. Watts v. United States, supra at 708 n. 3. The rule would be of little effectiveness unless enforced by this court. Of more importance, Rule 30 is but a codification of an old Supreme Court holding in Burns v. United States, 274 U.S. 328, 47 S.Ct. 650, 71 L.Ed. 1077 (1927), wherein the Court said at 336, 47 S.Ct. at 653:

Exceptions to a charge must be specifically made in order to give the court opportunity then and there to correct errors and omissions, if any. Pennsylvania R. R. Co. v. Minds, 250 U.S. 368, 375, 39 S.Ct. 53, 63 L.Ed. 1039 and cases cited; Allis v. *1089United States, 155 U.S. 117, 122, 15 S.Ct. 36, 39 L.Ed. 91 [1894]. Even if some of the instructions were erroneous, the exceptions taken were not such as to require a new trial.

The reason for requiring timely exceptions and requests with respect to final jury instructions is identical to the reason for requiring timely exceptions to trial errors: to give the trial court the opportunity to correct errors and omissions. See Pennsylvania R. R. Co. v. Minds, supra 250 U.S. at 375, 39 S.Ct. 53, 63 L.Ed. 1039; Allis v. United States, supra. Cf. Henderson v. Kibbe, 431 U.S. 145, 97 S.Ct. 1730, 1736, 52 L.Ed.2d 203 (1977) (failure to object to jury charge fatal to claim of constitutional error on collateral attack).

Acceptance of appellant’s contention here would prospectively deny this court the opportunity to make reasoned, case by case determinations that substantial rights were or were not prejudicially denied below. We deem this contrary to both case law and common sense. We hold that it is not plain error, per se, for a trial court not to give an immediate cautioning instruction on the use of evidence admitted for a limited purpose when no such instruction is requested.9

We hold, further, after having reviewed the entire record, that the trial court’s failure in the instant case to provide an immediate, unrequested cautionary instruction was not plain error.

Under the plain error standard, the error complained of must be so clearly prejudicial to substantial rights as to jeopardize the very fairness of the trial. Watts v. United States, supra at 709; Adams v. United States, supra; Bunter v. United States, supra. In the instant case, the trial court gave the jury a final charge which included an instruction on the limited purpose for which evidence of a prior inconsistent statement could be used. Thus, any prejudice resulting from the trial court’s failure to give such an instruction earlier was obviated sufficiently to ensure that appellant received a fair trial.10

The opinion of the division is reversed, and appellant’s conviction is affirmed.

So ordered.

dissenting, with whom MACK, Associate Judge, joins:

We can agree that it is a rare case in which this court has not followed the settled rule that an unobjected to error will not be noticed on appeal. But if the doctrine of plain error is ever to apply, I suggest that it must be applied here.

Government testimony at the trial described the details of a robbery, the stopping of a car driven by appellant shortly after the incident and the failure of the complaining witness to identify appellant as one of the robbers. A codefendant, Harry Allen, gave testimony exculpatory of appellant by denying that appellant had partici*1090pated in the robbery. He stated, as the majority notes, that throughout the robbery and its immediate aftermath appellant had been incapacitated by the effects of narcotics withdrawal and oblivious to the fact that a robbery had occurred. The witness was impeached in rebuttal with a contrary statement he had given after his arrest in which he implicated appellant in the robbery. The statement used to impeach Allen effectively controverted appellant’s sole defense to the crime and, in the absence of an immediate instruction on its limited admissibility, was most certainly viewed by the jury as substantive evidence of appellant’s guilt.1 In my judgment, the failure to give the cautionary instruction as to the only direct evidence implicating appellant in the crime was plain error necessitating reversal of appellant’s conviction. See generally United States v. Freeman, 169 U.S.App.D.C. 73, 514 F.2d 1314 (1975); United States v. Leonard, 161 U.S.App.D.C. 36, 494 F.2d 955 (1974); Jones v. United States, 128 U.S.App.D.C. 36, 40, 385 F.2d 296, 300 (1967); Coleman v. United States, 125 U.S.App.D.C. 246, 371 F.2d 343 (1966), cert. denied, 386 U.S. 945, 87 S.Ct. 979, 17 L.Ed.2d 875 (1967).

In the division opinion, citing Dixon v. United States,2 we acknowledged that generally where a party fails to request an instruction on limited admissibility of evidence, the failure of the trial judge to give such an instruction, sua sponte, will not be considered on appeal.3 We recognized as well, however, that there are occasions where the potential for jury confusion is so great in admitting prior inconsistent statements for a limited purpose that an immediate cautionary instruction is required.4 This is such a case.

Underlying the requirement that an immediate limiting instruction be given is the policy of restricting the jury’s exposure to hearsay evidence. Jones v. United States, supra. See also United States v. Leonard, supra. As hearsay, codefendant Allen’s pri- or inconsistent statement could not have properly been considered by the jury for the truth it stated. It could be considered as proving simply that the statement had been made since the mere fact that a witness has made a contradictory statement is relevant to an evaluation of credibility. It is apparent, however, that in reaching its verdict the jury credited Allen’s statement as substantive evidence of what had transpired in the robbery and that it was encouraged to do so by the prosecutor who, in closing argument, improperly emphasized the statement in a way which indicated that it could be so viewed. Considered as substantive evidence, Allen’s prior inconsistent statement effectively controverted appellant’s sole defense of nonparticipation in the crime.

There was no objection by counsel to the use of the prior inconsistent statement and no request for an immediate instruction. It is not helpful, however, to inject into the analysis of our problem gratuitous remarks about shrewd counsel sowing error in the record for what is in issue here is the fairness of the trial itself, not the dereliction of counsel. Moreover, the trial court is not without responsibility to guard against the injection into the trial of prejudicial error at the moment that possibility arises.5 Be*1091cause of that grave danger here, the trial judge should have been alert to avert the error and could have easily done so.

The majority has now disavowed, at least in part, this court's opinion in Lofty v. United States, D.C.App., 277 A.2d 99 (1971). Lofty was not dispositive of the instant case, however. We speak here not of government surprise by unexpected testimony of its own witness but of jury confusion occasioned by the unexplained use of a prior inconsistent statement. It is true that the same vice — the likelihood that the jury will consider the statement as substantive evidence rather than a limited attack on credibility — is present in both situations, but Dixon teaches that each case is to be decided on its own unique facts. Dixon v. United States, supra at 98. The majority does not explain why there should be a difference between the impeachment of one’s own witness and impeachment of a defense witness. Indeed, there is none. Jones v. United States, supra, 128 U.S.App.D.C. at 40, 385 F.2d at 300. Regardless of whose witness is being impeached, it is unrealistic to assume that jurors hearing testimony of a prior inconsistent statement would consider that statement as anything but substantive evidence unless they were instructed otherwise.

I close, as I began, by noting again that appellate courts do not readily grant relief under the plain error rule. Yet not to do so under the facts of this case is to ignore prejudicial error affecting substantial rights and the essential fairness of appellant’s trial. I would reverse appellant’s conviction and remand for a new trial.