NOTICE: This opinion is subject to formal revision before publication in
    the preliminary print of the United States Reports.  Readers are
    requested to notify the Reporter of Decisions, Supreme Court of the
    United States, Washington, D.C. 20543, of any typographical or other
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                       SUPREME COURT OF THE UNITED STATES

                                    --------
                                   No. 91-1306
                                    --------

                       UNITED STATES, PETITIONER v. GUY W.
                                                ____
                         OLANO, JR., AND RAYMOND M. GRAY

                       ON WRIT OF CERTIORARI TO THE UNITED
                      STATES COURT OF APPEALS FOR THE NINTH
                                     CIRCUIT

                                [April 26, 1993]

  JUSTICE O'CONNOR delivered the opinion of the Court.

  The question in this case is whether the presence of alternate jurors during
jury deliberations was a "plain error" that the Court of Appeals was authorized
to correct under Rule 52(b) of the Federal Rules of Criminal Procedure.
                                        I
  Each of the respondents, Guy W. Olano, Jr., and Raymond M. Gray, served on the
board of directors of a savings and loan association.  In 1986, the two were
indicted in the Western District of Washington on multiple federal charges for
their participation in an elaborate loan "kickback" scheme.  Their joint jury
trial with five other codefendants commenced in March, 1987.  All of the parties
agreed that fourteen jurors would be selected to hear the case, and that the two
alternates would be identified before deliberations began.
  On May 26, shortly before the end of the 3-month trial, the District Court
suggested to the defendants that the two alternate jurors, soon to be
identified, might be allowed to attend deliberations along with the regular
jurors:

   ". . . I'd just like you to think about it, you have a day, let me know, it's
   just a suggestion and you 

                                91-1306 - OPINION

2                            UNITED STATES v. OLANO
                                          ____

   can - if there is even one person who doesn't like it we won't do it, but it
   is a suggestion that other courts have followed in long cases where jurors
   have sat through a lot of testimony, and that is to let the alternates go in
   but not participate, but just to sit in on deliberations.
     "It's strictly a matter of courtesy and I know many judges have done it
   with no objections from counsel.  One of the other things it does is if they
   don't participate but they're there, if an emergency comes up and people
   decide they'd rather go with a new alternate rather than 11, which the rules
   provide, it keeps that option open.  It also keeps people from feeling
   they've sat here for three months and then get just kind of kicked out.  But
   it's certainly not worth - unless it's something you all agree to, it's not
   worth your spending time hassling about, you know what I mean?  You've got
   too much else on your mind.  I don't want it to be a big issue; it's just a
   suggestion.  Think about it and let me know."  App. 79.

  The matter arose again the next day, in an ambiguous exchange between Gray's
counsel and the District Court:

     "THE COURT: [H]ave you given any more thought as to whether you want the
   alternates to go in and not participate, or do you want them out?
     "MR. ROBISON [counsel for Gray]: We would ask they not.
     "THE COURT: Not."  App. 82.

One day later, on May 28, the last day of trial, the District Court for a third
time asked the defendants whether they wanted the alternate jurors to retire
into the jury room.  Counsel for defendant Davy Hilling gave an unequivocal,
affirmative answer.

     "THE COURT: Well, Counsel, I received your alternates. Do I understand that
   the defendants

                                91-1306 - OPINION

                             UNITED STATES v. OLANO                            3
                                          ____

   now - it's hard to keep up with you, Counsel.  It's sort of a day by day -
   but that's all right.  You do all agree that all fourteen deliberate? 
     "Okay.  Do you want me to instruct the two alternates not to participate in
   deliberation?
     "MR. KELLOGG [counsel for Hilling]: That's what I was on my feet to say. 
   It's my understanding that the conversation was the two alternates go back
   there instructed that they are not to take part in any fashion in the
   deliberations."  App. 86.

This discussion, like the preceding two, took place outside the hearing of the
jurors.  As before, both Gray's counsel and Olano's counsel were present.  Gray,
too, attended all three discussions.  Olano may not have attended the third - he
claims that the marshal failed to return him to the courtroom in time - but he
was present at the first two.  
  The District Court concluded that Hilling's counsel was speaking for the other
defendants as well as his own client.  None of the other counsel intervened
during the colloquy between the District Court and Hilling's counsel on May 28,
nor did anyone object later the same day when the court instructed the jurors
that the two alternates would be permitted to attend deliberations.  The court
instructed:

   "We have indicated to you that the parties would be selecting alternates at
   this time.  I am going to inform you who those alternates are, but before I
   do, let me tell you, I think it was a difficult selection for all concerned,
   and since the law requires that there be a jury of twelve, it is only going
   to be a jury of twelve.  But what we would like to do in this case is have
   all of you go back so that even the alternates can be there for the
   deliberations, but according to the law, the alternates must not participate
   in the deliberations.  It's going to be hard, but if you are an

                                91-1306 - OPINION

4                            UNITED STATES v. OLANO
                                          ____

   alternate, we think you should be there because things do happen in the
   course of lengthy jury deliberations, and if you need to step in, we want you
   to be able to step in having heard the deliberations.  But we are going to
   ask that you not participate.
     "The alternates are Norman Sargent and Shirley Kinsella.  I am going to ask
   at this time now, ladies and gentlemen, that you retire to the jury room and
   begin your deliberations."  App. 89-90.

During deliberations, one of the alternate jurors was excused at his request. 
The other alternate remained until the jury returned with its verdict.
  Both respondents were convicted on a number of charges.  They appealed to the
United States Court of Appeals for the Ninth Circuit.  934 F. 2d 1425 (1991). 
The Court of Appeals reversed certain counts for insufficient evidence and then
considered whether the presence of alternate jurors during jury deliberations
violated Rule 24(c) of the Federal Rules of Criminal Procedure:

   "The court may direct that not more than 6 jurors in addition to the regular
   jury be called and impanelled to sit as alternate jurors.  Alternate jurors
   in the order in which they are called shall replace jurors who, prior to the
   time the jury retires to consider its verdict, become or are found to be
   unable or disqualified to perform their duties. . . .  An alternate juror who
   does not replace a regular juror shall be discharged after the jury retires
   to consider its verdict."

Because respondents had not objected to the alternates' presence, the court
applied a "plain error" standard under Rule 52(b).  Noting that "[w]e have not
previously directly resolved the question of the validity of a verdict when
alternate jurors are permitted to be present during the jury's deliberations,"
the court relied on the "language of Rule 24(c), Rule 23(b), the Advisory
Committee Notes to Rule 23, and related Ninth Circuit precedent" to hold that

                                91-1306 - OPINION

                             UNITED STATES v. OLANO                            5
                                          ____

Rule 24(c) barred alternate jurors from attending jury deliberations unless the
defendant, on the record, explicitly consented to their attendance.  934 F. 2d,
at 1436-1437.  The court found that Rule 24(c) was violated in the instant case,
because "the district court did not obtain individual waivers from each
defendant personally, either orally or in writing."  Id., at 1438.  It then held
                                                     ___
that the presence of alternates in violation of Rule 24(c) was "inherently
prejudicial" and reversible per se.  Ibid. 
                            ______   _____
     "We cannot fairly ascertain whether in a given case the alternate jurors
   followed the district court's prohibition on participation.  However, even if
   they heeded the letter of the court's instructions and remained orally mute
                                                                   ______
   throughout, it is entirely possible that their attitudes, conveyed by facial
   expressions, gestures or the like, may have had some effect upon the decision
   of one or more jurors."  Ibid. (internal quotation marks and brackets
                            _____
   omitted).

Finally, in a footnote, the court decided that "[b]ecause the violation is
inherently prejudicial and because it infringes upon a substantial right of the
defendants, it falls within the plain error doctrine."  Id., at 1439, n. 23.
                                                        ___
  The Court of Appeals vacated respondents' remaining convictions and did not
reach the other "substantial issues" that they had raised.  Id., at 1428, n. 3. 
                                                            ___
We granted certiorari to clarify the standard for "plain error" review by the
Courts of Appeals under Rule 52(b).  504  U. S. ___ (1992).
                                       II
  "No procedural principle is more familiar to this Court than that a
constitutional right," or a right of any other sort, "may be forfeited in
criminal as well as civil cases by the failure to make timely assertion of the
right before a tribunal having jurisdiction to determine it."  Yakus v. United
                                                               _____    ______
States, 321 U. S. 414, 444 (1944).  Rule 52(b) of the Federal Rules of Criminal
______
Procedure, which governs

                                91-1306 - OPINION

6                            UNITED STATES v. OLANO
                                          ____

on appeal from criminal proceedings, provides the Court of Appeals a limited
power to correct errors that were forfeited because not timely raised in the
District Court.  The Rule has remained unchanged since the original version of
the Criminal Rules, and was intended as "a restatement of existing law." 
Advisory Committee's Notes on Fed. Rule Crim. Proc. 52, 18 U. S. C. App., p.
833.  It is paired, appropriately, with Rule 52(a), which governs nonforfeited
errors.  Rule 52 provides:

     "(a) HARMLESS ERROR.  Any error, defect, irregularity or variance which
   does not affect substantial rights shall be disregarded.
     "(b) PLAIN ERROR.  Plain errors or defects affecting substantial rights may
   be noticed although they were not brought to the attention of the court." 

  Although "[a] rigid and undeviating judicially declared practice under which
courts of review would invariably and under all circumstances decline to
consider all questions which had not previously been specifically urged would be
out of harmony with . . . the rules of fundamental justice," Hormel v.
                                                             ______
Helvering, 312 U. S. 552, 557 (1941), the authority created by Rule 52(b) is
_________
circumscribed.  There must be an "error" that is "plain" and that "affect[s]
substantial rights."  Moreover, Rule 52(b) leaves the decision to correct the
forfeited error within the sound discretion of the Court of Appeals, and the
court should not exercise that discretion unless the error "`seriously
affect[s] the fairness, integrity or public reputation of judicial
proceedings.'"  United States v. Young, 470 U. S. 1, 15 (1985) (quoting United
                _____________    _____                                  ______
States v. Atkinson, 297 U. S. 157, 160 (1936)).
______    ________
                                        A
  Rule 52(b) defines a single category of forfeited-but-reversible error. 
Although it is possible to read the Rule in the disjunctive, as creating two
separate categories -  ``plain errors'' and ``defects affecting substantial
rights'' - 

                                91-1306 - OPINION

                             UNITED STATES v. OLANO                            7
                                          ____

that reading is surely wrong.  See Young, supra, at 15, n. 12 (declining to
                                   _____  _____
adopt disjunctive reading).  As we explained in Young, the phrase "error or
                                                _____
defect" is more simply read as "error."  Ibid.  The forfeited error "may be
                                         _____
noticed" only if it is "plain" and "affect[s] substantial rights."  More
precisely, the Court of Appeals may correct the error (either vacating for a new
                                    _______
trial, or reversing outright) only if it meets these criteria.  The appellate
court must consider the error, putative or real, in deciding whether the
judgment below should be overturned, but cannot provide that remedy unless Rule
52(b) applies (or unless some other provision authorizes the error's correction,
an issue that respondents do not raise).
  The first limitation on appellate authority under Rule 52(b) is that there
indeed be an "error."  Deviation from a legal rule is "error" unless the rule
has been waived.  For example, a defendant who knowingly and voluntarily pleads
guilty in conformity with the requirements of Rule 11 cannot have his conviction
vacated by the Court of Appeals on the grounds that he ought to have had a
trial.  Because the right to trial is waivable, and because the defendant who
enters a valid guilty plea waives that right, his conviction without a trial is
not "error."
   Waiver is different from forfeiture.  Whereas forfeiture is the failure to
make the timely assertion of a right, waiver is the "intentional relinquishment
or abandonment of a known right."  Johnson v. Zerbst, 304 U. S. 458, 464 (1938);
                                   _______    ______
see, e.g., Freytag v. Commissioner, 501 U. S. ___, ___, n. 2 (1991) (SCALIA,
     ____
        _  _______    ____________
J., concurring in part and concurring in judgment) (distinguishing between
"waiver" and "forfeiture"); Spritzer, Criminal Waiver, Procedural Default and
the Burger Court, 126 U. Pa. L. Rev. 473, 474-477 (1978) (same); Westen, Away
from Waiver: A Rationale for the Forfeiture of Constitutional Rights in Criminal
Procedure, 75 Mich. L. Rev. 1214, 1214-1215 (1977) (same).  Whether a particular
right is waivable; whether the defendant must participate personally in the

                                91-1306 - OPINION

8                            UNITED STATES v. OLANO
                                          ____

waiver; whether certain procedures are required for waiver; and whether the
defendant's choice must be particularly informed or voluntary, all depend on the
right at stake.  See, e.g., 2 W. LaFave & J. Israel, Criminal Procedure S 11.6
                      ____
                         _
(1984) (allocation of authority between defendant and counsel); Dix, Waiver in
Criminal Procedure: A Brief for More Careful Analysis, 55 Texas L. Rev. 193
(1977) (waivability and standards for waiver).  Mere forfeiture, as opposed to
waiver, does not extinguish an "error" under Rule 52(b).  Although in theory it
could be argued that "[i]f the question was not presented to the trial court no
error was committed by the trial court, hence there is nothing to review,"
Orfield, The Scope of Appeal in Criminal Cases, 84 U. Pa. L. Rev. 825, 840
(1936), this is not the theory that Rule 52(b) adopts.  If a legal rule was
violated during the District Court proceedings, and if the defendant did not
waive the rule, then there has been an "error" within the meaning of Rule 52(b)
despite the absence of a timely objection.
  The second limitation on appellate authority under Rule 52(b) is that the
error be "plain."  "Plain" is synonymous with "clear" or, equivalently,
"obvious."  See Young, supra, at 17, n. 14; United States v. Frady, 456 U. S.
                _____  ______               _____________    _____
152, 163 (1982).  We need not consider the special case where the error was
unclear at the time of trial but becomes clear on appeal because the applicable
law has been clarified.  At a minimum, the Court of Appeals cannot correct an
error pursuant to Rule 52(b) unless the error is clear under current law.
  The third and final limitation on appellate authority under Rule 52(b) is that
the plain error "affec[t] substantial rights."  This is the same language
employed in Rule 52(a), and in most cases it means that the error must have been
prejudicial: It must have affected the outcome of the District Court
proceedings.  See, e.g., Bank of Nova Scotia v. United States, 487 U. S. 250,
                   ____
                      _  ___________________    _____________
255-257 (1988); United States v. Lane, 474 U. S. 438, 454-464 (1986)
                _____________    ____

                                91-1306 - OPINION

                             UNITED STATES v. OLANO                            9
                                          ____

(Brennan, J., concurring in part and dissenting in part); Kotteakos v. United
                                                          _________    ______
States, 328 U. S. 750, 758-765 (1946).  When the defendant has made a timely
______
objection to an error and Rule 52(a) applies, the Court of Appeals normally
engages in a specific analysis of the District Court record - a so-called
"harmless error" inquiry - to determine whether the error was prejudicial.  Rule
52(b) normally requires the same kind of inquiry, with one important difference:
It is the defendant rather than the Government who bears the burden of
persuasion with respect to prejudice.  In most cases, the Court of Appeals
cannot correct the forfeited error unless the defendant shows that the error was
prejudicial.  See Young, 470 U. S., at 17, n. 14 ("[F]ederal courts have
                  _____
consistently interpreted the plain-error doctrine as requiring an appellate
court to find that the claimed error . . . had [a] prejudicial impact on the
jury's deliberations").  This burden-shifting is dictated by a subtle but
important difference in language between the two parts of Rule 52: while Rule
52(a) precludes error-correction only if the error "does not affect substantial
                                                         ___
rights" (emphasis added), Rule 52(b) authorizes no remedy unless the error does
                                                                           ____
"affec[t] substantial rights."  See also Note, Appellate Review in a Criminal
Case of Errors Made Below Not Properly Raised and Reserved, 23 Miss. L. J. 42,
57 (1951) (summarizing existing law) ("The error must be real and such that it
probably influenced the verdict . . .").
  We need not decide whether the phrase "affecting substantial rights" is always
synonymous with "prejudicial."  See generally Arizona v. Fulminate, 499 U. S.
                                              _______    _________
___, ___ (1991) (slip op., at 8) (constitutional error may not be found harmless
if error deprives defendant of the "`basic protections [without which] a
criminal trial cannot reliably serve its function as a vehicle for determination
of guilt or innocence, and no criminal punishment may be regarded as
fundamentally fair'") (quoting Rose v. Clark, 478 U. S. 570, 577-578 (1986)). 
                               ____    _____
There may be a special

                                91-1306 - OPINION

10                           UNITED STATES v. OLANO
                                          ____

category of forfeited errors that can be corrected regardless of their effect on
the outcome, but this issue need not be addressed.  Nor need we address those
errors that should be presumed prejudicial if the defendant cannot make a
specific showing of prejudice.  Normally, although perhaps not in every case,
the defendant must make a specific showing of prejudice to satisfy the
"affecting substantial rights" prong of Rule 52(b).

                                        B
  Rule 52(b) is permissive, not mandatory.  If the forfeited error is "plain"
and "affect[s] substantial rights," the Court of Appeals has authority to order
correction, but is not required to do so.  The language of the Rule ("may be
noticed"), the nature of forfeiture, and the established appellate practice that
Congress intended to continue, all point to this conclusion.  "[I]n criminal
cases, where the life, or as in this case the liberty, of the defendant is at
stake, the courts of the United States, in the exercise of a sound discretion,
may notice [forfeited error]."  Sykes v. United States, 204 F. 909, 913-914 (CA8
                                _____    _____________
1913).  Accord, Crawford v. United States, 212 U. S. 183, 194 (1909); former
                ________    _____________
Supreme Court Rule 27.6 (1939) (cited in Advisory Committee's Notes on Fed. Rule
Crim. Proc. Rule 52(b), p. 833) (``the court, at its option, may notice a plain
error not assigned or specified'').
  We previously have explained that the discretion conferred by Rule 52(b)
should be employed "`in those circumstances in which a miscarriage of justice
would otherwise result.'"  Young, supra, at 15 (quoting Frady, supra, at 163,
                           ____________                 _____________
n. 14)).  In our collateral-review jurisprudence, the term "miscarriage of
justice" means that the defendant is actually innocent.  See, e.g., Sawyer v.
                                                              ____
                                                                 _  ______
Whitley, 505 U. S. ___, ___-___ (1992) (slip op., at 4-6).  The Court of Appeals
_______
should no doubt correct a plain forfeited error that causes the conviction or
sentencing of an actually innocent defendant, see, e.g., Wiborg v. United
                                                   ____
                                                      _  ______    ______
States, 163
______

                                91-1306 - OPINION

                             UNITED STATES v. OLANO                           11
                                          ____

U. S. 632 (1896), but we have never held that a Rule 52(b) remedy is only
                                                                     ____
warranted in cases of actual innocence.
  Rather, the standard that should guide the exercise of remedial discretion
under Rule 52(b) was articulated in United States v. Atkinson, 297 U. S. 157
                                    _____________    ________
(1936).  The Court of Appeals should correct a plain forfeited error affecting
substantial rights if the error "seriously affect[s] the fairness, integrity or
public reputation of judicial proceedings."  Id., at 160.  As we explained in
                                             ___
Young, the "standard laid down in United States v. Atkinson [was] codified in
_____                             _____________    ________
Federal Rule of Criminal Procedure 52(b)," 470 U. S., at 7, and we repeatedly
have quoted the Atkinson language in describing plain-error review.  See id., at
                ________                                             ___ ___
15; Frady, 456 U. S., at 163, n. 13; Silber v. United States, 370 U. S. 717, 718
    _____                            ______    _____________
(1962) (per curiam); Johnson v. United States, 318 U. S. 189, 200 (1943); United
       _____________ _______    _____________                             ______
States v. Socony-Vacuum Oil Co., 310 U. S. 150, 239 (1940); see also Connor v.
______    _____________________                                      ______
Finch, 431 U. S. 407, 421, n. 19 (1977) (civil appeal).  An error may "seriously
_____
affect the fairness, integrity or public reputation of judicial proceedings"
independent of the defendant's innocence.  Conversely, a plain error affecting
substantial rights does not, without more, satisfy the Atkinson standard, for
                                                       ________
otherwise the discretion afforded by Rule 52(b) would be illusory.  
  With these basic principles in mind, we turn to the instant case.
                                       III
  The presence of alternate jurors during jury deliberations is no doubt a
deviation from Rule 24(c).  The Rule explicitly states: "An alternate juror who
does not replace a regular juror shall be discharged after the jury retires to
consider its verdict."  It is a separate question whether such deviation amounts
to "error" when the defendant consents to the alternates' presence.  The
Government supposes that there was indeed an "error" in this case, on the
premise that Rule 24(c) is nonwaivable, see Reply

                                91-1306 - OPINION

12                           UNITED STATES v. OLANO
                                          ____

Brief for United States 9, n. 4, and we assume without deciding that this
premise is correct.  The Government also essentially concedes that the "error"
was "plain."  See id., at 8-9, and n. 4.  
                  ___
  We therefore focus our attention on whether the error "affect[ed] substantial
rights" within the meaning of Rule 52(b), and conclude that it did not.  The
presence of alternate jurors during jury deliberations is not the kind of error
that "affect[s] substantial rights" independent of its prejudicial impact.  Nor
have respondents made a specific showing of prejudice.  Finally, we see no
reason to presume prejudice here.
  Assuming arguendo that certain errors "affec[t] substantial rights"
           ________
independent of prejudice, the instant violation of Rule 24(c) is not such an
error.  Although the presence of alternate jurors does contravene "`the
cardinal principle that the deliberations of the jury shall remain private and
secret,'"  Advisory Committee's Notes on Fed. Rule Crim. Proc. 23(b), 18
U. S. C. App., p. 785 (quoting United States v. Virginia Erection Corp., 335
                               _____________    _______________________
F. 2d 868, 872 (CA4 1964)), the primary if not exclusive purpose of jury privacy
and secrecy is to protect the jury's deliberations from improper influence. 
"[I]f no harm resulted from this intrusion [of an alternate juror into the jury
room,] reversal would be pointless."  United States v. Watson, 669 F. 2d 1374,
                                      _____________    ______
1391 (CA11 1982).  We generally have analyzed outside intrusions upon the jury
for prejudicial impact.  See, e.g., Parker v. Gladden, 385 U. S. 363 (1967)
                              ____
                                 _  ______    _______
(per curiam) (bailiff's comments to jurors, such as "Oh that wicked fellow he is
 __________
guilty," were prejudicial); Patton v. Yount, 467 U. S. 1025 (1984) (pretrial
                            ______    _____
publicity was not prejudicial); Holbrook v. Flynn, 475 U. S. 560 (1986)
                                ________    _____
(presence of uniformed state troopers in courtroom was not prejudicial).  A
prime example is Remmer v. United States, 347 U. S. 227 (1954), where an
                 ______    _____________
outsider had communicated with a juror during a criminal trial, appearing to
offer a bribe, and the Federal Bureau of

                                91-1306 - OPINION

                             UNITED STATES v. OLANO                           13
                                          ____

Investigation then had investigated the incident.  We noted that "[t]he sending
of an F. B. I. agent in the midst of a trial to investigate a juror as to his
conduct is bound to impress the juror," and remanded for the District Court to
"determine the circumstances, the impact thereof upon the juror, and whether or
not it was prejudicial, in a hearing with all interested parties permitted to
participate."  Id., at 229-230.  
               ___
  This "intrusion" jurisprudence was summarized in Smith v. Phillips, 455 U. S.
                                                   _____    ________
209 (1982):

   "[D]ue process does not require a new trial every time a juror has been
   placed in a potentially compromising situation.  Were that the rule, few
   trials would be constitutionally acceptable. . . .  [I]t is virtually
   impossible to shield jurors from every contact or influence that might
   theoretically affect their vote.  Due process means a jury capable and
   willing to decide the case solely on the evidence before it, and a trial
   judge ever watchful to prevent prejudicial occurrences and to determine the
   effect of such occurrences when they happen."  Id., at 217. 
                                                  ___

There may be cases where an intrusion should be presumed prejudicial, see,
e.g., Patton, supra, at 1031-1035; Turner v. Louisiana, 379 U. S. 466 (1965),
____
   _  ______  _____                ______    _________
but a presumption of prejudice as opposed to a specific analysis does not change
the ultimate inquiry: Did the intrusion affect the jury's deliberations and
thereby its verdict?  We cannot imagine why egregious comments by a bailiff to a
juror (Parker) or an apparent bribe followed by an official investigation
      ________
(Remmer) should be evaluated in terms of "prejudice," while the mere presence of
________                                                             ________
alternate jurors during jury deliberations should not.  Of course, the issue
here is whether the alternates' presence sufficed to establish remedial
authority under Rule 52(b), not whether it violated the Sixth Amendment or Due
Process Clause, but we see no reason to depart from the normal interpre-

                                91-1306 - OPINION

14                           UNITED STATES v. OLANO
                                          ____

tation of the phrase "affecting substantial rights."
  The question, then, is whether the instant violation of Rule 24(c) prejudiced
respondents, either specifically or presumptively.  In theory, the presence of
alternate jurors during jury deliberations might prejudice a defendant in two
different ways: either because the alternates actually participated in the
deliberations, verbally or through "body language"; or because the alternates'
presence exerted a "chilling" effect on the regular jurors.  See Watson, supra,
                                                                 ______  ______
at 1391; United States v. Allison, 481 F. 2d 468, 472 (CA5 1973).  Conversely,
         _____________    _______
"if the alternate in fact abided by the court's instructions to remain orally
silent and not to otherwise indicate his views or attitude . . . and if the
presence of the alternate did not operate as a restraint upon the regular
jurors' freedom of expression and action, we see little substantive difference
between the presence of [the alternate] and the presence in the juryroom of an
unexamined book which had not been admitted into evidence."  Id., at 472.
                                                             ____
  Respondents have made no specific showing that the alternate jurors in this
case either participated in the jury's deliberations or "chilled" deliberation
by the regular jurors.  We need not decide whether testimony on this score by
the alternate jurors or the regular jurors, through affidavits or at a Remmer-
                                                                       ______
like hearing, would violate Rule 606(b) of the Federal Rules of Evidence,
compare Watson, supra, at 1391-1392, and n. 17, with United States v. Beasley,
        _______ _____                                _____________    _______
464 F. 2d 468 (CA10 1972), or whether the Courts of Appeals have authority to
remand for Remmer-like hearings on plain-error review.  Respondents have never
           ______
requested a hearing, and thus the record before us contains no direct evidence
that the alternate jurors influenced the verdict.  On this record, we are not
persuaded that the instant violation of Rule 24(c) was actually prejudicial.
  Nor will we presume prejudice for purposes of the Rule 52(b) analysis here. 
The Court of Appeals was incorrect

                                91-1306 - OPINION

                             UNITED STATES v. OLANO                           15
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in finding the error "inherently prejudicial."  934 F. 2d, at 1439.  Until the
close of trial, the two alternate jurors were indistinguishable from the twelve
regular jurors.  Along with the regular jurors, they commenced their office with
an oath, see Tr. 212 (Mar. 2, 1987), received the normal initial admonishment,
see id., at 212-218, heard the same evidence and arguments, and were not
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identified as alternates until after the District Court gave a final set of
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instructions, see App. 89-90.  In those instructions, the District Court
specifically enjoined the jurors that "according to the law, the alternates must
not participate in the deliberations," and reiterated, "we are going to ask that
you not participate."  Ibid.  The Court of Appeals should not have supposed that
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this injunction was contravened.  "[It is] the almost invariable assumption of
the law that jurors follow their instructions."  Richardson v. Marsh, 481 U. S.
                                                 __________    _____
200, 206 (1987).  "[We] presum[e] that jurors, conscious of the gravity of their
task, attend closely the particular language of the trial court's instructions
in a criminal case and strive to understand, make sense of, and follow the
instructions given them."  Francis v. Franklin, 471 U. S. 307, 324, n. 9 (1985). 
                           _______    ________
See also Strickland v. Washington, 466 U. S. 668, 694 (1984) (in assessing
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prejudice for purposes of ineffective-assistance claim, "a court should presume
. . . that the judge or jury acted according to law").  Nor do we think that the
mere presence of alternate jurors entailed a sufficient risk of "chill" to
justify a presumption of prejudice on that score.
  In sum, respondents have not met their burden of showing prejudice under Rule
52(b).  Whether the Government could have met its burden of showing the absence
of prejudice, under Rule 52(a), if respondents had not forfeited their claim of
error, is not at issue here.  This is a plain-error case, and it is respondents
who must persuade the appellate court that the deviation from Rule 24(c) was
prejudicial.
  Because the conceded error in this case did not ``affec[t]

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16                           UNITED STATES v. OLANO
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substantial rights,'' the Court of Appeals had no authority to correct it.  We
need not consider whether the error, if prejudicial, would have warranted
correction under the Atkinson standard as ``seriously affect[ing] the fairness,
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integrity or public reputation of judicial proceedings.''  The judgment of the
Court of Appeals is reversed, and the case is remanded for further proceedings
consistent with this opinion.
                                                                     So ordered.
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