dissenting.
The Sixth and Fourteenth Amendments guarantee a person accused of a crime the right to the aid of a lawyer in preparing and presenting his defense. It has long been settled that “the right to counsel is the right to the effective assist-*707anee of counsel.” McMann v. Richardson, 397 U. S. 759, 771, n. 14 (1970). The state and lower federal courts have developed standards for distinguishing effective from inadequate assistance.1 Today, for the first time, this Court attempts to synthesize and clarify those standards. For the most part, the majority’s efforts are unhelpful. Neither of its two principal holdings seems to me likely to improve the adjudication of Sixth Amendment claims. And, in its zeal to survey comprehensively this field of doctrine, the majority makes many other generalizations and suggestions that I find unacceptable. Most importantly, the majority fails to take adequate account of the fact that the locus of this case is a capital sentencing proceeding. Accordingly, I join neither the Court’s opinion nor its judgment.
I
The opinion of the Court revolves around two holdings. First, the majority ties the constitutional minima of attorney performance to a simple “standard of reasonableness.” Ante, at 688. Second, the majority holds that only an error of counsel that has sufficient impact on a trial to “undermine confidence in the outcome” is grounds for overturning a conviction. Ante, at 694. I disagree with both of these rulings.
A
My objection to the performance standard adopted by the Court is that it is so malleable that, in practice, it will either have no grip at all or will yield excessive variation in the manner in which the Sixth Amendment is interpreted and applied by different courts. To tell lawyers and the lower courts that counsel for a criminal defendant must behave *708“reasonably” and must act like “a reasonably competent attorney,” ante, at 687, is to tell them almost nothing. In essence, the majority has instructed judges called upon to assess claims of ineffective assistance of counsel to advert to their own intuitions regarding what constitutes “professional” representation, and has discouraged them from trying to develop more detailed standards governing the performance of defense counsel. In my view, the Court has thereby not only abdicated its own responsiblity to interpret the Constitution, but also impaired the ability of the lower courts to exercise theirs.
The debilitating ambiguity of an “objective standard of reasonableness” in this context is illustrated by the majority’s failure to address important issues concerning the quality of representation mandated by the Constitution. It is an unfortunate but undeniable fact that a person of means, by selecting a lawyer and paying him enough to ensure he prepares thoroughly, usually can obtain better representation than that available to an indigent defendant, who must rely on appointed counsel, who, in turn, has limited time and resources to devote to a given case. Is a “reasonably competent attorney” a reasonably competent adequately paid retained lawyer or a reasonably competent appointed attorney? It is also a fact that the quality of representation available to ordinary defendants in different parts of the country varies significantly. Should the standard of performance mandated by the Sixth Amendment vary by locale?2 The majority offers no clues as to the proper responses to these questions.
The majority defends its refusal to adopt more specific standards primarily on the ground that “[n]o particular set of detailed rules for counsel’s conduct can satisfactorily take ac*709count of the variety of circumstances faced by defense counsel or the range of legitimate decisions regarding how best to represent a criminal defendant.” Ante, at 688-689. I agree that counsel must be afforded “wide latitude” when making “tactical decisions” regarding trial strategy, see ante, at 689; cf. infra, at 712, 713, but many aspects of the job of a criminal defense attorney are more amenable to judicial oversight. For example, much of the work involved in preparing for a trial, applying for bail, conferring with one’s client, making timely objections to significant, arguably erroneous rulings of the trial judge, and filing a notice of appeal if there are color-able grounds therefor could profitably be made the subject of uniform standards.
The opinion of the Court of Appeals in this case represents one sound attempt to develop particularized standards designed to ensure that all defendants receive effective legal assistance. See 693 F. 2d 1243, 1251-1258 (CA5 1982) (en banc). For other, generally consistent efforts, see United States v. Decoster, 159 U. S. App. D. C. 326, 333-334, 487 F. 2d 1197, 1203-1204 (1973), disapproved on rehearing, 199 U. S. App. D. C. 359, 624 F. 2d 196 (en banc), cert. denied, 444 U. S. 944 (1979); Coles v. Peyton, 389 F. 2d 224, 226 (CA4), cert. denied, 393 U. S. 849 (1968); People v. Pope, 23 Cal. 3d 412, 424-425, 590 P. 2d 859, 866 (1979); State v. Harper, 57 Wis. 2d 543, 550-557, 205 N. W. 2d 1, 6-9 (1973).3 By refusing to address the merits of these proposals, and indeed suggesting that no such effort is worthwhile, the opinion of the Court, I fear, will stunt the development of constitutional doctrine in this area.
*710B
I object to the prejudice standard adopted by the Court for two independent reasons. First, it is often very difficult to tell whether a defendant convicted after a trial in which he was ineffectively represented would have fared better if his lawyer had been competent. Seemingly impregnable cases can sometimes be dismantled by good defense counsel. On the basis of a cold record, it may be impossible for a reviewing court confidently to ascertain how the government’s evidence and arguments would have stood up against rebuttal and cross-examination by a shrewd, well-prepared lawyer. The difficulties of estimating prejudice after the fact are exacerbated by the possibility that evidence of injury to the defendant may be missing from the record precisely because of the incompetence of defense counsel.4 In view of all these impediments to a fair evaluation of the probability that the outcome of a trial was affected by ineffectiveness of counsel, it seems to me senseless to impose on a defendant whose lawyer has been shown to have been incompetent the burden of demonstrating prejudice.
*711Second and more fundamentally, the assumption on which the Court’s holding rests is that the only purpose of the constitutional guarantee of effective assistance of counsel is to reduce the chance that innocent persons will be convicted. In my view, the guarantee also functions to ensure that convictions are obtained only through fundamentally fair procedures.5 The majority contends that the Sixth Amendment is not violated when a manifestly guilty defendant is convicted after a trial in which he was represented by a manifestly ineffective attorney. I cannot agree. Every defendant is entitled to a trial in which his interests are vigorously and conscientiously advocated by an able lawyer. A proceeding in which the defendant does not receive meaningful assistance in meeting the forces of the State does not, in my opinion, constitute due process.
In Chapman v. California, 386 U. S. 18, 23 (1967), we acknowledged that certain constitutional rights are “so basic to a fair trial that their infraction can never be treated as harmless error.” Among these rights is the right to the assistance of counsel at trial. Id., at 23, n. 8; see Gideon v. Wainwright, 372 U. S. 335 (1963).6 In my view, the right *712to effective assistance of counsel is entailed by the right to counsel, and abridgment of the former is equivalent to abridgment of the latter.7 I would thus hold that a showing that the performance of a defendant’s lawyer departed from constitutionally prescribed standards requires a new trial regardless of whether the defendant suffered demonstrable prejudice thereby.
II
Even if I were inclined to join the majority’s two central holdings, I could not abide the manner in which the majority elaborates upon its rulings. Particularly regrettable are the majority’s discussion of the “presumption” of reasonableness to be accorded lawyers’ decisions and its attempt to prejudge the merits of claims previously rejected by lower courts using different legal standards.
A
In defining the standard of attorney performance required by the Constitution, the majority appropriately notes that many problems confronting criminal defense attorneys admit of “a range of legitimate” responses. Ante, at 689. And the majority properly cautions courts, when reviewing a lawyer’s selection amongst a set of options, to avoid the hubris of hindsight. Ibid. The majority goes on, however, to suggest that reviewing courts should “indulge a strong presumption that counsel’s conduct” was constitutionally acceptable, ibid.; see ante, at 690, 696, and should “appl[y] a heavy measure of deference to counsel’s judgments,” ante, at 691.
I am not sure what these phrases mean, and I doubt that they will be self-explanatory to lower courts. If they denote nothing more than that a defendant claiming he was denied effective assistance of counsel has the burden of proof, I *713would agree. See United States v. Cronic, ante, at 658. But the adjectives “strong” and “heavy” might be read as imposing upon defendants an unusually weighty burden of persuasion. If that is the majority’s intent, I must respectfully dissent. The range of acceptable behavior defined by “prevailing professional norms,” ante, at 688, seems to me sufficiently broad to allow defense counsel the flexibility they need in responding to novel problems of trial strategy. To afford attorneys more latitude, by “strongly presuming” that their behavior will fall within the zone of reasonableness, is covertly to legitimate convictions and sentences obtained on the basis of incompetent conduct by defense counsel.
The only justification the majority itself provides for its proposed presumption is that undue receptivity to claims of ineffective assistance of counsel would encourage too many defendants to raise such claims and thereby would clog the courts with frivolous suits and “dampen the ardor” of defense counsel. See ante, at 690. I have more confidence than the majority in the ability of state and federal courts expeditiously to dispose of meritless arguments and to ensure that responsible, innovative lawyering is not inhibited. In my view, little will be gained and much may be lost by instructing the lower courts to proceed on the assumption that a defendant’s challenge to his lawyer’s performance will be insubstantial.
B
For many years the lower courts have been debating the meaning of “effective” assistance of counsel. Different courts have developed different standards. On the issue of the level of performance required by the Constitution, some courts have adopted the forgiving “farce-and-mockery” standard,8 while others have adopted various versions of *714the "reasonable competence” standard.9 On the issue of the level of prejudice necessary to compel a new trial, the courts have taken a wide variety of positions, ranging from the stringent “outcome-determinative” test,10 to the rule that a showing of incompetence on the part of defense counsel automatically requires reversal of the conviction regardless of the injury to the defendant.11
The Court today substantially resolves these disputes. The majority holds that the Constitution is violated when defense counsel’s representation falls below the level expected of reasonably competent defense counsel, ante, at 687-691, and so affects the trial that there is a “reasonable probability” that, absent counsel’s error, the outcome would have been different, ante, at 691-696.
Curiously, though, the Court discounts the significance of its rulings, suggesting that its choice of standards matters little and that few if any cases would have been decided differently if the lower courts had always applied the tests announced today. See ante, at 696-697. Surely the judges in the state and lower federal courts will be surprised to learn that the distinctions they have so fiercely debated for many years are in fact unimportant.
The majority’s comments on this point seem to be prompted principally by a reluctance to acknowledge that today’s decision will require a reassessment of many previously rejected ineffective-assistance-of-counsel claims. The majority’s unhappiness on this score is understandable, but its efforts to mitigate the perceived problem will be ineffectual. Nothing the majority says can relieve lower courts that hith*715erto have been using standards more tolerant of ineffectual advocacy of their obligation to scrutinize all claims, old as well as new, under the principles laid down today.
► — I l l — H
The majority suggests that, “[f]or purposes of describing counsel’s duties,” a capital sentencing proceeding “need not be distinguished from an ordinary trial.” Ante, at 687. I cannot agree.
The Court has repeatedly acknowledged that the Constitution requires stricter adherence to procedural safeguards in a capital case than in other cases.
“[T]he penalty of death is qualitatively different from a sentence of imprisonment, however long. Death, in its finality, differs more from life imprisonment than a 100-year prison term differs from one of only a year or two. Because of that qualitative difference, there is a corresponding difference in the need for reliability in the determination that death is the appropriate punishment in a specific case.” Woodson v. North Carolina, 428 U. S. 280, 305 (1976) (plurality opinion) (footnote omitted).12
The performance of defense counsel is a crucial component of the system of protections designed to ensure that capital punishment is'administered with some degree of rationality. “Reliability” in the imposition of the death sentence can be approximated only if the sentencer is fully informed of “all possible relevant information about the individual defendant whose fate it must determine.” Jurek v. Terns, 428 U. S. 262, 276 (1976) (opinion of Stewart, Powell, and Stevens, JJ.). The job of amassing that information and presenting it *716in an organized and persuasive manner to the sentencer is entrusted principally to the defendant’s lawyer. The importance to the process of counsel’s efforts,13 combined with the severity and irrevocability of the sanction at stake, require that the standards for determining what constitutes “effective assistance” be applied especially stringently in capital sentencing proceedings.14
It matters little whether strict scrutiny of a claim that ineffectiveness of counsel resulted in a death sentence is achieved through modification of the Sixth Amendment standards or through especially careful application of those standards. Justice Brennan suggests that the necessary adjustment of the level of performance required of counsel in capital sentencing proceedings can be effected simply by construing the phrase, “reasonableness under prevailing professional norms,” in a manner that takes into account the nature of the impending penalty. Ante, at 704-706. Though I would prefer a more specific iteration of counsel’s duties in this special context,151 can accept that proposal. However, when instructing lower courts regarding the probability of impact upon the outcome that requires a resentencing, I think the Court would do best explicitly to modify the legal standard itself.16 In my view, a person on death row, whose counsel’s performance fell below constitutionally acceptable levels, should not be compelled to demonstrate a “reasonable prob*717ability” that he would have been given a life sentence if his lawyer had been competent, see ante, at 694; if the defendant can establish a significant chance that the outcome would have been different, he surely should be entitled to a redeter-mination of his fate. Cf. United States v. Agurs, 427 U. S. 97, 121-122 (1976) (Marshall, J., dissenting).17
1 — 1 <1
The views expressed m the preceding section oblige me to dissent from the majority’s disposition of the case before us.18 It is undisputed that respondent’s trial counsel made virtually no investigation of the possibility of obtaining testimony from respondent’s relatives, friends, or former employers pertaining to respondent’s character or background. Had counsel done so, he would have found several persons willing and able to testify that, in their experience, respondent was a responsible, nonviolent man, devoted to his family, and active in the affairs of his church. See App. 338-365. Respondent contends that his lawyer could have and should have used that testimony to "humanize” respondent, to counteract the impression conveyed by the trial that he was little more than a cold-blooded killer. Had this evidence been admitted, respondent argues, his chances of obtaining a life sentence would have been significantly better.
*718Measured against the standards outlined above, respondent’s contentions are substantial. Experienced members of the death-penalty bar have long recognized the crucial importance of adducing evidence at a sentencing proceeding that establishes the defendant’s social and familial connections. See Goodpaster, The Trial for Life: Effective Assistance of Counsel in Death Penalty Cases, 58 N. Y. U. L. Rev. 299, 800-808, 334-335 (1983). The State makes a colorable— though in my view not compelling — argument that defense counsel in this case might have made a reasonable “strategic” decision not to present such evidence at the sentencing hearing on the assumption that an unadorned acknowledgment of respondent’s responsibility for his crimes would be more likely to appeal to the trial judge, who was reputed to respect persons who accepted responsiblity for their actions.19 But however justifiable such a choice might have been after counsel had fairly assessed the potential strength of the mitigating evidence available to him, counsel’s failure to make any significant effort to find out what evidence might be garnered from respondent’s relatives and acquaintances surely cannot be described as “reasonable.” Counsel’s failure to investigate is particularly suspicious in light of his candid admission that respondent’s confessions and conduct in the course of the trial gave him a feeling of “hopelessness” regarding the possibility of saving respondent’s life, see App. 383-384, 400-401.
*719That the aggravating circumstances implicated by respondent’s criminal conduct were substantial, see ante, at 700, does not vitiate respondent’s constitutional claim; judges and juries in cases involving behavior at least as egregious have shown mercy, particularly when afforded an opportunity to see other facets of the defendant’s personality and life.20 Nor is respondent’s contention defeated by the possibility that the material his counsel turned up might not have been sufficient to establish a statutory mitigating circumstance under Florida law; Florida sentencing judges and the Florida Supreme Court sometimes refuse to impose death sentences in cases “in which, even though statutory mitigating circumstances do not outweigh statutory aggravating circumstances, the addition of nonstatutory mitigating circumstances tips the scales in favor of life imprisonment.” Barclay v. Florida, 463 U. S. 939, 964 (1983) (Stevens, J., concurring in judgment) (emphasis in original).
If counsel had investigated the availability of mitigating evidence, he might well have decided to present some such material at the hearing. If he had done so, there is a significant chance that respondent would have been given a life sentence. In my view, those possibilities, conjoined with the unreasonableness of counsel’s failure to investigate, are more than sufficient to establish a violation of the Sixth Amendment and to entitle respondent to a new sentencing proceeding.
I respectfully dissent.
See Note, Identifying and Remedying Ineffective Assistance of Criminal Defense Counsel: A New Look After United States v. Decoster, 93 Harv. L. Rev. 752, 756-758 (1980); Note, Effective Assistance of Counsel: The Sixth Amendment and the Pair Trial Guarantee, 50 U. Chi. L. Rev. 1380, 1386-1387, 1399-1401, 1408-1410 (1983).
Cf., e. g., Moore v. United States, 432 F. 2d 730, 736 (CA3 1970) (defining the constitutionally required level of performance as “the exercise of the customary skill and knowledge which normally prevails at the time and place”).
For a review of other decisions attempting to develop guidelines for assessment of ineffective-assistance-of-counsel claims, see Erickson, Standards of Competency for Defense Counsel in a Criminal Case, 17 Am. Crim. L. Rev. 233, 242-248 (1979). Many of these decisions rely heavily on the standards developed by the American Bar Association. See ABA Standards for Criminal Justice 4-1.1 — 4-8.6 (2d ed. 1980).
Cf. United States v. Ellison, 557 F. 2d 128, 131 (CA7 1977). In discussing the related problem of measuring injury caused by joint representation of conflicting interests, we observed:
“[T]he evil... is in what the advocate finds himself compelled to refrain from doing, not only at trial but also as to possible pretrial plea negotiations and in the sentencing process. It may be possible in some cases to identify from the record the prejudice resulting from an attorney’s failure to undertake certain trial tasks, but even with a record of the sentencing hearing available it would be difficult to judge intelligently the impact of a conflict on the attorney’s representation of a client. And to assess the impact of a conflict of interests on the attorney’s options, tactics, and decisions in plea negotiations would be virtually impossible. Thus, an inquiry into a claim of harmless error here would require, unlike most cases, unguided speculation.” Holloway v. Arkansas, 435 U. S. 475, 490-491 (1978) (emphasis in original).
When defense counsel fails to take certain actions, not because he is “compelled” to do so, but because he is incompetent, it is often equally difficult to ascertain the prejudice consequent upon his omissions.
See United States v. Decoster, 199 U. S. App. D. C. 359, 454-457, 624 F. 2d 196, 291-294 (en banc) (Bazelon, J., dissenting), cert. denied, 444 U. S. 944 (1979); Note, 93 Harv. L. Rev., at 767-770.
In eases in which the government acted in a way that prevented defense counsel from functioning effectively, we have refused to require the defendant, in order to obtain a new trial, to demonstrate that he was injured. In Glasser v. United States, 315 U. S. 60, 75-76 (1942), for example, we held:
“To determine the precise degree of prejudice sustained by [a defendant] as a result of the court’s appointment of [the same counsel for two codefen-dants with conflicting interests] is at once difficult and unnecessary. The right to have the assistance of counsel is too fundamental and absolute to allow courts to indulge in nice calculations as to the amount of prejudice arising from its denial.”
As the Court today acknowledges, United States v. Cronic, ante, at 662, n. 31, whether the government or counsel himself is to blame for the inadequacy of the legal assistance received by a defendant should make no difference in deciding whether the defendant must prove prejudice.
See United States v. Yelardy, 567 F. 2d 863, 865, n. 1 (CA6), cert. denied, 439 U. S. 842 (1978); Beasley v. United States, 491 F. 2d 687, 696 (CA6 1974); Commonwealth v. Badger, 482 Pa. 240, 243-244, 393 A. 2d 642, 644 (1978).
See, e. g., State v. Pacheco, 121 Ariz. 88, 91, 588 P. 2d 830, 833 (1978); Hoover v. State, 270 Ark. 978, 980, 606 S. W. 2d 749, 751 (1980); Line v. State, 272 Ind. 353, 354-355, 397 N. E. 2d 975, 976 (1979).
See, e. g., Trapnell v. United States, 725 F. 2d 149, 156 (CA2 1983); Cooper v. Fitzharris, 586 F. 2d 1325, 1328-1330 (CA9 1978) (en banc), cert. denied, 440 U. S. 974 (1979).
See, e. g., United States v. Decoster, 199 U. S. App. D. C., at 370, and n. 74, 624 F. 2d, at 208, and n. 74 (plurality opinion); Knight v. State, 394 So. 2d 997, 1001 (Fla. 1981).
See n. 7, supra.
See also Zant v. Stephens, 462 U. S. 862, 884-885 (1983); Eddings v. Oklahoma, 455 U. S. 104, 110-112 (1982); Lockett v. Ohio, 438 U. S. 586, 604 (1978) (plurality opinion).
See Goodpaster, The Trial for Life: Effective Assistance of Counsel in Death Penalty Cases, 58 N. Y. U. L. Rev. 299, 303 (1983).
As Justice Brennan points out, ante, at 704, an additional reason for examining especially carefully a Sixth Amendment challenge when it pertains to a capital sentencing proceeding is that the result of finding a constitutional violation in that context is less disruptive than a finding that counsel was incompetent in the liability phase of a trial.
See Part I-A, supra. For a sensible effort to formulate guidelines for the conduct of defense counsel in capital sentencing proceedings, see Goodpaster, supra, at 343-345, 360-362.
For the purposes of this and the succeeding section, I assume, solely for the sake of argument, that some showing of prejudice is necessary to state a violation of the Sixth Amendment. But cf. Part I-B, supra.
As I read the opinion of the Court, it does not preclude this kind of adjustment of the legal standard. The majority defines “reasonable probability” as “a probability sufficient to undermine confidence in the outcome.” Ante, at 694. In view of the nature of the sanction at issue, and the difficulty of determining how a sentencer would have responded if presented with a different set of facts, it could be argued that a lower estimate of the likelihood that the outcome of a capital sentencing proceeding was influenced by attorney error is sufficient to “undermine confidence” in that outcome than would be true in an ordinary criminal case.
Adhering to my view that the death penalty is unconstitutional under all circumstances, Gregg v. Georgia, 428 U. S. 153, 231 (1976) (Marshall, J., dissenting), I would vote to vacate respondent’s sentence even if he had not presented a substantial Sixth Amendment claim.
Two considerations undercut the State’s explanation of counsel’s decision. First, it is not apparent why adducement of evidence pertaining to respondent’s character and familial connections would have been inconsistent with respondent’s acknowledgment that he was responsible for his behavior. Second, the Florida Supreme Court possesses — and frequently exercises — the power to overturn death sentences it deems unwarranted by the facts of a case. See State v. Dixon, 283 So. 2d 1, 10 (1973). Even if counsel’s decision not to try to humanize respondent for the benefit of the trial judge were deemed reasonable, counsel’s failure to create a record for the benefit of the State Supreme Court might well be deemed unreasonable.
See, e. g., Farmer & Kinard, The Trial of the Penalty Phase (1976), reprinted in 2 California State Public Defender, California Death Penalty Manual N-33, N-45 (1980).